Kids These Days! A Cross-Temporal Meta-Analysis of Changes in Emotional and Behavioral Problems of Population-Based Samples Over the Past Decades

Kids These Days! A Cross-Temporal Meta-Analysis of Changes in Emotional and Behavioral Problems of Population-Based Samples Over the Past Decades | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Systematic Review Kids These Days! A Cross-Temporal Meta-Analysis of Changes in Emotional and Behavioral Problems of Population-Based Samples Over the Past Decades Boglarka Vekety, Tamas Koi, Alexander H. N. Logemann, John Protzko, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7905820/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract There is a general conception that mental health problems are increasing in younger generations, though little objective comparisons exist. The current meta-analysis examined changes in subclinical mean-level emotional and behavioral problems among population-based samples of youth (1-18 years) globally over the last four decades. We searched systematically in PubMed, Web of Science, Scopus, EBSCO and Google Scholar with pre-registered criteria [removed for masked review]. Included studies ( k = 175, N = 418,528) used the standardized and cross-culturally validated Child Behavior Checklist with parents, teachers and self-reports. A cross-temporal meta-analysis was conducted with data points between 1981 to 2019. Age, sex, response rate, continent were used as moderators. Meta-regression analyses, with year of data collection as predictor, showed that total emotional and behavioral problems did not change in the past 40 years. However, there was evidence of change in specific problems. We find strong evidence for decreased aggression in children over time (parent report: k = 47, b year = -0.18, p = .009, 95%CI[-0.31,-0.05]; self-report: k = 9, b year = -0.41, p = .006, 95%CI[-0.66,-0.16]). There was evidence of a decrease in parent reported externalizing problems in middle childhood ( k = 60, b year = -0.21, p < .001, 95%CI[-0.30,-0.11]) and specifically in teenage boys ( k = 12, b year = -0.27, p = .049, 95%CI[-0.54,0]). In contrast, there were increases in parent-reported attention ( k = 63, b year= 0.24, p = .004, 95%CI[0.08,0.40]) and thought problems ( k = 40, b year= 0.09, p = .006, 95%CI[0.03,0.15]) for youth overall, and anxiety-depression symptoms specifically in teens ( k = 12, b year = 0.26, p = .011, 95%CI[0.07,0.45]), although with high heterogeneity. In sum, our results do not support concerns that children and young people today experience more emotional and behavioural problems than previous generations, rather, they experience subtly different patterns of difficulties. However, an important limitation of the study is that post COVID-19 changes were not studied. emotional problems behavioral problems trends youth Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Public Significance Statement This cross-temporal meta-analysis finds that ’kids these days’ have not been experiencing an overall decline in mental health over the past 40 years - contrary to common conception. However, there is strong evidence that the incidence of some emotional and behavioral problems has changed over the past decades. For example, aggression has decreased, while there is some evidence that attention and thought problems in children and teens, and anxiety-depression in teens might have increased. Introduction Understanding how emotional and behavioral problems in youth have changed over time is central to the broader study of mental health and psychopathology. Psychologists, educators, and policymakers are increasingly concerned with the apparent rise of mental health problems both in adults (e.g., Buecker et al., 2021; Zheng & Echave, 2021) and in children and adolescents (e.g., the Lancet Psychiatry Commission on youth mental health by McGorry et al., 2024). These concerns raise fundamental questions about the origins, development and classification of mental health disorders. A longstanding question is whether the observed increase in mental health disorder diagnoses simply reflects genuine changes in prevalence or is simply the result of improved detection and diagnostic practices, often referred to as the prevalence inflation hypothesis (Foulkes & Andrews, 2023). Addressing this issue requires not only an analysis of diagnostic trends but also a focus on underlying emotional and behavioral problems that precede clinical-level disorders. The present study definitively examines secular trends in emotional and behavioral problems that often precede formal diagnoses, among young people across the last decades. If mental health disorders are indeed increasing, one would also expect to see a concurrent increase in associated subclinical difficulties. Emotional and behavioral problems is an umbrella term that includes psychological difficulties related to one’s emotions and behavior. When the severity of certain difficulties is high, one is diagnosed with a mental health disorder. However, two to three times more people experience these difficulties below the threshold of a clinical diagnosis as above (Haller et al., 2014; Johnson et al., 2022). Subthreshold psychopathology early in life through late adolescence increases the risk of developing mental health disorders later in life (Schiavone et al., 2019; Shankman et al., 2009; Zhong et al., 2024). These life stages are especially malleable, offering critical opportunities for interventions that support long-term mental health (Jones & Meredith, 2000; Murray et al., 2015). There have been cross-temporal findings that suggest negative changes in the mental health of today’s youth, especially in adolescents and young adults, compared to previous generations: loneliness (Buecker et al., 2021), attention/working memory: (Graves et al., 2021; Wongupparaj et al., 2017), emotional intelligence: (Khan et al., 2021), depression: (Twenge, 2020), resilience: (Zhao et al., 2022). Yet, other studies highlight positive trends. For example, children’s self-control, specifically the ability to delay gratification, has improved globally from the 1960s to the 2010s (Protzko, 2020). In certain countries, cross-cohort comparisons reveal improvements (declines) in emotional and behavioral difficulties, rule-breaking, and aggression (Achenbach et al., 2003; Degli Esposti et al., 2023; Langley et al., 2017). In addition to these mixed findings, some indicating improvements and some indicating a decline in the mental health of current generations of youth, there is a general conception that the overall mental health in the current generation of youth is in decline in their qualities relative to earlier generations (Protzko, 2020; Protzko & Schooler, 2019; Russell et al., 2010). Such intuitions need to be definitely grounded in large population-based research. Ascriptions of generational decline is termed the ’kids these days’ effect (Protzko & Schooler, 2019, 2022, Protzko, 2020). However, such perceptions of decline are affected by memory and perception bias such as projecting our current qualities onto the youth of our past and comparing this skewed and nostalgic view with youth these days, and noticing the limitations of others more easily in something we have already mastered (Protzko & Schooler, 2019). Even experts are not immune to the ‘kids these days’ effect (Protzko, 2020), underscoring the need for empirical evidence to clarify whether, and in what ways, the mental health of young people has actually changed over time. Thus, instead of relying on a biased memory or biased intuitions, even expert ones, definitive quantitative evidence is required. This study seeks to answer several key questions: Has the mental health of young people genuinely declined over the past decades? Are there certain emotional and behavioral difficulties that affect today's young generations less or more? Do these changes vary by age, sex, region, or methodological approach? To address these questions, we investigated changes in subclinical levels of emotional and behavioral problems among youth over recent decades, and identified particularly vulnerable subgroups. Understanding the scale and nature of these changes in an objective way is essential for uncovering the drivers of secular trends and for designing effective, targeted interventions. These issues also hold widespread public interest, given the perception that socio-cultural and environmental shifts in recent decades may have adversely impacted young people’s mental well-being. This review extends previous systematic global research in three key ways: (a) by focusing on subclinical rather than clinical-level problems (Piao et al., 2022); (b) by incorporating data collected after 2010 (Bor et al., 2014; Collishaw, 2015); and (c) by employing cross-temporal meta-analysis, a powerful method for examining changes in psychological variables over time using large-scale, globally representative data in the absence of longitudinal datasets (Buecker et al., 2021). In the sections that follow, we present current evidence on the roles of age, sex, and cultural context in mean-level emotional problems, and review prior research on secular trends. Mean-Level Emotional and Behavioral Problems Among Young People The mean-level of emotional and behavioral problems is an important indicator of mental health in the youth population, with a higher mean-level of problems indicating worse mental health (Ford & Parker, 2016). Emotional and behavioral difficulties are typically distinguished into internalizing and externalizing problems (Holland et al., 2017). Externalizing problems are related to conflict with others (e.g., rule-breaking or deviant behavior, aggression, also known as conduct problems), while internalizing problems reflect inner distress (e.g., anxiety, depression, psychosomatic symptoms or withdrawal, also known as emotional problems) (Holland et al., 2017). Besides externalizing and internalizing problems, youth commonly exhibit other problems, such as attention, thought, or social problems (Achenbach, 2001). Generally, there are age, sex, and cultural differences in mean-level emotional and behavioral problems but also according to the informant. Internalizing problems become more prominent with age and are more common for girls, while externalizing problems become less prominent with age and are more common for boys (C.-Y. Chen et al., 2008; Gutman & Codiroli McMaster, 2020; L. Rescorla et al., 2007; Shaikh & Shinde, 2018). Studies show that when rating themselves, children and adolescents typically report more problems relative to assessments by parents or teachers, and parents report more problems than teachers (except for externalizing problems) (Achenbach et al., 2002; Huang, 2017; Tick et al., 2007; van der Ende et al., 2012). Regarding intercultural differences, although there have been cross-society differences reported between mean-level emotional and behavioral problems, variance was considerably greater within each society than between societies (L. Rescorla et al., 2007; L. A. Rescorla et al., 2019). Externalizing problems, especially aggression have been shown to be the least variant across cultures, while thought problems seem to be the most variant (Ivanova, Achenbach, et al., 2007; Ivanova, Dobrean, et al., 2007; L. A. Rescorla et al., 2007). The longest time and worldwide used measurement instrument of mean-level emotional and behavioral problems that has been translated into 80 languages are the rating scales of the Achenbach System of Empirically Based Assessment (ASEBA) consisting of the Child Behavior Checklist (CBCL) rated by the parent, the Teacher’s Report Form (TRF), and the Youth Self-Report (YSR) (Achenbach, 1991c, 1991b, 1991a). Along with the ASEBA rating scales, the Strengths and Difficulties Questionnaire (SDQ) is also a widely used instrument to measure mean-level emotional and behavioral difficulties (Goodman, 1997) However, the ASEBA battery has been used for longer, has more items and captures more psychological problems from more informants than the SDQ (e.g., the ASEBA includes self-report of youth as well). Both instruments identify children with subthreshold and threshold mental health disorders by cut-off scores based on validity measures of population-based samples (Smedje et al., 1999) Threshold or clinical-level emotional and behavioral problems are more commonly measured by diagnostic interviews with parents or children, for instance according to the DSM criteria by the American Psychological Association (APA). However, substantial changes have been made over the past decades in the diagnostic criteria between versions of the DSM. This makes it more difficult to compare the prevalence of clinical-level mental-health problems of youth from different decades (Collishaw, 2015). In the following section we will review findings about the secular changes in prevalence rates of clinical-level mental health disorders, as well as changes in subthreshold difficulties. Temporal Changes in Emotional and Behavioral Problems of Youth Temporal changes in psychopathology, defined as population-level fluctuations in the prevalence or expression of psychological symptoms over time, are more than descriptive trends (Armitage et al., 2024; Ford, 2008). Secular changes challenge prevailing theories about the origins and course of mental illness. Traditional models of psychopathology, particularly those emphasizing genetic etiology, have sometimes assumed a degree of stability across time and context. However, notable shifts in prevalence within a single generation imply that environmental and psychosocial factors may also play a substantial role (Borg et al., 2025; Fombonne, 1998; Rutter & Smith, 1995). If certain emotional or behavioral problems are increasing among youth, this suggests either that new risk factors have emerged or that existing protective factors are no longer as effective (Fine et al., 2022; Zoellner et al, 2024). In either case, temporal trends compel a re-evaluation of longstanding assumptions about the relative roles of genes and environment in the development of mental illness. Recent advances in psychiatric genetics, including large-scale genome-wide association studies (GWAS) by the Psychiatric Genomics Consortium (Sullivan et al., 2018), have highlighted the heritability of various psychiatric disorders, such as major depressive disorder (MDD). Yet these findings also underscore the complexity of gene–environment interplay. Models of gene–environment interaction and differential susceptibility (e.g., Belsky & Pluess, 2009) suggest that genetic predispositions are not deterministic, but instead confer varying degrees of sensitivity to environmental contexts. As the environments inhabited by children and adolescents have changed, due to shifts in technology use, educational pressures, family dynamics, or socioeconomic stressors, the developmental expression of underlying vulnerabilities also might have changed. Temporal change, in this sense, reflects not just epidemiological drift but evolving developmental pathways shaped by historical and cultural context. From a public health perspective, understanding these temporal patterns is essential for forecasting needs, allocating resources, and evaluating the effectiveness of mental health interventions. In order to plan and deliver effective mental health services, it is essential to know how many children are experiencing symptoms, what kinds of problems are most common, and whether these patterns are shifting over time (Ford, 2008). If the prevalence of certain difficulties is increasing, or if rates are stable despite the proliferation of intervention programs, this raises critical questions about the suitability and efficacy of existing approaches. It is possible that current interventions, developed in earlier decades, may not adequately address the challenges facing today’s youth. Evidence-based practices may need to be updated or re-contextualized to remain effective for contemporary cohorts. Temporal change also has implications for how clinical psychology conceptualizes and measures psychopathology. The dominant taxonomic systems, such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Diseases (ICD), use categorical models that define mental disorders based on symptom thresholds. However, these thresholds often exclude individuals with subclinical symptoms who nonetheless experience significant distress or impairment. Emerging dimensional models, such as the Hierarchical Taxonomy of Psychopathology (HiTOP; Kotov et al., 2017), address these limitations by conceptualizing psychopathology as a spectrum. These models allow researchers to capture gradations of severity, from mild to severe, and are particularly well-suited for detecting secular trends. For instance, dimensional assessments can reveal whether subthreshold symptoms are increasing over time, that is an important finding that may be masked by categorical diagnostic approaches. Moreover, secular trends differ by country, type of disorder, and developmental period, which adds additional complexity to etiological theories. Cross-national differences may reflect a range of methodological, cultural, and policy-related factors, but they also suggest that the social environment plays a powerful role in shaping mental health outcomes (Cosma et al., 2020; Fombonne, 1998). If rates of a given disorder rise in one context but fall or remain stable in another, this variability demands careful investigation into context-specific risk factors. Such trends force researchers to consider the malleability of youth behavior problems and whether some of these issues are more temporally and culturally sensitive than previously assumed (Zhao et al., 2021). The assumption that emotional and behavioral problems are inherently stable may obscure their dynamic responsiveness to shifting environmental and sociocultural forces. In sum, the study of temporal changes in youth psychopathology is not merely a historical or descriptive endeavor. It provides critical insights into the developmental origins of mental illness, the relevance and responsiveness of current clinical practices, and the conceptual frameworks used to define psychological disorders. As prevalence rates, symptom profiles, and risk factors evolve over time, so too must the tools and theories used by clinical scientists and practitioners. Ultimately, a deeper understanding of these changes can inform more accurate models of psychopathology, more responsive mental health services, and more effective prevention and intervention strategies for future generations. Previous Studies on Secular Changes in Clinical-Level Problems In 2019 8.8% of children and adolescents were diagnosed with mental health disorders globally (Piao et al., 2022). Within the subtypes of various mental disorders, anxiety disorder accounted for the highest prevalence, followed by developmental intellectual disability and attention-deficit/hyperactivity disorder. The Global Disease Burden study revealed a slight decrease (by 1.3%) in the prevalence rates of mental disorders from 1990 to 2019 in youth aged 0–19 years (Piao et al., 2022). In these three decades, the highest prevalence rate among mental disorders changed from developmental intellectual disability to anxiety disorders. The most significant increases in the prevalence of different mental disorders were observed for depression (an increase of 10.9% from 1990), conduct disorder (an increase of 8.2% from 1990), and anxiety disorder (an increase of 1.6% from 1990), while the most significant decreases were reported for developmental intellectual disability and attention-deficit/hyperactivity disorder. Secular Changes in Subclinical Problems There are no recent global findings about the cross-temporal changes in subclinical-level emotional and behavioral problems of youth but only country-specific studies (see Table 1). Certainly, there are advantages of national epidemiological cross-cohort comparisons, longitudinal studies, and cross-temporal meta-analysis as these can directly influence the policy making of a country, however, there are a lot of countries where no such study exists (see Table 1). Those countries can benefit even more from global results. There were only two systematic studies that examined global time trends in emotional and behavioral problems: one that showed no change in externalizing and internalizing problems between 1990 and 2010 for youth aged 0-18 years, but an increase in internalizing problems for 12-18 year old girls (Bor et al., 2014); the other showed an increase in emotional problems for all age groups, and no change in hyperactivity or conduct problems (Collishaw, 2015). These global results need to be updated by including data after 2010, improved with the empirical method of a cross-temporal meta-analysis and by investigating a more fine-grained picture on different emotional and behavioral problems. As Table 1 shows, country-specific studies on secular changes in emotional and behavioral problems are more common, especially in certain countries such as the UK, the Netherlands, the USA, Brazil or China. The most robust evidence is grouped around convergent evidence across multiple informants but these studies are limited in number (3 from the UK, 1 from the US, and 1 from the Netherlands) (see Table 1). In the UK the following trends were detected: between 1974-1999 increased emotional and conduct problems and no change in hyperactivity according to parent- and self-report (Collishaw et al., 2004); between 1986-2006 increased emotional problems reported by parents and teenage girls (Collishaw et al., 2010); between 1999-2008 total problems and conduct problems reducing in both sexes according to parents and teachers (Sellers et al., 2015). However, it is important to note that teachers’ and parents’ reports diverged regarding some problems, especially in emotional problems and hyperactivity (Maughan et al., 2008; Sellers et al., 2015). In the Netherlands, parents, teachers and children all reported no change in aggression, social problems and thought problems between 1983-2003 (Tick et al., 2007) but reports were divergent in changes in total, internalizing and externalizing problems. In the USA between 1976-1999 both parents and teachers reported an increase in total problems until 1989, and then a decrease until 1999 (Achenbach et al., 2003). Further strong evidence of changes in the mental health of young people comes from cross-sectional studies with annual measurements over long periods of time, such as the Health Behavior in School-aged Children study (HBSC). In Scotland and Sweden HBSC studies reported an increase in self-reported somatic complaints between 1998-2018 (Inchley et al., 2023) and in the number of students reporting frequent complaints (Högberg et al., 2023). However, only some somatic and mood symptoms are studied in the HBSC, not a diverse fine-categorized set of emotional and behavioral problems. In summary, previous evidence on secular changes in subclinical emotional and behavior problems show mixed results and is limited in the following ways: (a) there is a need for a more fine-grained classification of emotional and behavioral problems to study the time trends more specifically; (b) evidence across multiple informants is rare, which gathers the most robust evidence (e.g., there is a very limited number of previous studies on secular changes in the mental health of teens that is not self-reported); (c) there are no empirical studies with a broader framework in time and location. The current review overcomes these limitations by: (a-b) applying a more fine-grained classification system for emotional and behavioral problems by using the ASEBA battery with multiple informant (parents, teachers, and self reports); (c) studying a longer time period than previous studies, (over four decades) and reporting on global changes. Previous cross-cohort and cross-temporal studies showed that time trends of changes in emotional and behavioral problems may also differ by age, sex, and geographical location, thus these moderators were also taken into account when exploring time trends. Table 2 Summary of Previous Studies About Secular Changes Across Time in Subclinical Emotional and Behavioral Problems First author & publication year Study type Year of data Country Trend Age Informant Europe Sourander, 2004 Cross-cohort comparison (2 cohorts) 1989-1999 Finland ↓ conduct and total problem for boys 8 years parent Sellers, 2014 Cross-cohort comparison (3 cohorts) 1999-2008 UK ↓ total, conduct, and emotional problems, ↔ hyperactivity 7 years parent ↓ total and conduct problems, ↓ hyperactivity for boys, ↔ emotional problems teacher Tick, 2007 Cross-cohort comparison (2 cohorts) 1989-2003 Netherlands ↓ total problems 2-3 years parent Hölling, 2014 Cross-cohort comparison (2 cohorts) 2003-2012 Germany ↑ conduct problems,↔ hyperactivity 3-13 years parent ↑ emotional problems,↔ hyperactivity 14-17 years Santalahti, 2005 Cross-cohort comparison (2 cohorts) 1990-2000 Finland ↑ somatic problems 8-9 years parent Langley 2017 Cross-cohort comparison (2 cohorts) 2005-2015 Wales ↓ total problems, hyperactivity, aggression and rule-breaking for boys, ↔ for girls 4-7 years parent ↓ total problems, hyperactivity, aggression and rule-breaking for girls, ↔ for boys 7-12 years Collishaw (2004, 2007) Cross-cohort comparison (3 cohorts) 1974-1999 UK ↑ conduct problems, emotional problems, ↔ hyperactivity 15-16 years parent self Collishaw (2010, 2012) Cross-cohort comparison (2 cohorts) 1986-2006 UK ↑ emotional problems 16-17 years parent ↑ emotional problems for girls, ↔ for boys self Maughan, 2008 Cross-cohort comparison (2 cohorts) 1999-2004 UK ↓ total problems, conduct problems, hyperactivity, ↔ emotional problems 5-15 years parent ↔ total problems, conduct problems, hyperactivity, ↑ emotional problems teacher Tick, 2007 Cross-cohort comparison (2 cohorts) 1983-2003 Netherlands ↑ total, internalizing problems, ↔ aggression, thought and social problems 6-16 years parent ↔ total, externalizing, internalizing problems, aggression, thought or social problems, ↑ attention problems increase teacher ↓ total problems for boys, ↑ internalizing for girls self Armitage 2023 Cross-cohort comparison (2 cohorts) 2013-2019 UK ↑ emotional problems with an earlier onset of problems 11-16 years parent von Soest, 2014 Cross-cohort comparison (3 cohorts) 1992-2010 Norway ↑ depression for boys from 1992 to 2002, ↓ conduct problems for boys from 2002 to 2010 16-17 years self Torikka, 2014 Longitudinal study (10 assessments) 2000-2011 Finland ↔ in mild or moderate depression, ↑ in severe depression for both sexes 14-16 years self Sweeting (2009, 2010) Cross-cohort comparison (3 cohorts) 1987-2006 UK ↑ depression 15 years self Sigfusdottir, 2008 Cross-cohort comparison (4 cohorts) 1997-2006 Iceland ↑ depression for girls, anxiety for both sexes 14-15 years self Wangby, 2005 Cross-cohort comparison (2 cohorts) 1970-1996 Sweden ↔ emotional problems 15 years self Inchley 2023 Cross-cohort comparison (6 cohorts) 1998-2018 Scotland ↑ feeling low, feeling nervous, sleep difficulties and backache 11-15 years self Högber, 2022 Cross-cohort comparison (6 cohorts) 1998-2018 Sweden ↑ in the proportion of students with frequent somatic complaints 11-15 years self Anthony, 2023 Cross-cohort comparison (3 cohorts) 2013-2019 Wales ↑ emotional problems 11-16 years self North & South America Matijasevich 2014 Cross-cohort comparison (2 cohorts) 1993-2004 Brazil ↓ total problems, aggression and attention problems 4 years parent Degli Esposti, 2023 Cross-cohort comparison (3 cohorts) 1997-2019 Brazil ↑ total problems 1997-2010, ↓ aggression and rule-breaking 2010 -2020 4 years parent Achenbach, 2003 Cross-cohort comparison (2 cohorts) 1976-1999 USA ↑ total problems 1976-1989, ↓ total problems 1990-1999 7-16 years parent teacher Mason, 2023 Cross-cohort comparison (2 cohorts) 1997-2017 USA ↑ somatic problems and anxiety, ↔ social problems, depression, and rule-breaking 5-18 years teacher Keyes, 2019 Cross-cohort comparison (28 cohorts) 1991-2018 USA ↓ depression 1991-2011, ↑ 2011-2018 13-18 years self Asia Lin, 2007 Cross-cohort comparison (2 cohorts) 1993-2003 China ↑ emotional problems, ↑ externalizing problems for girls 6-14 years parent Su, 2020 Cross-temporal meta-analysis 1989-2018 China ↑ depression for boys, ↔ for girls 12-18 years self Xin, 2010 Cross-temporal meta-analysis 1992-2005 China ↑ anxiety 12-17 years self Du, 2025 Cross-temporal meta-analysis 2010-2023 China ↔ depression 2010-2020, ↑ 2021-2023 10-19 years self Australia Fleming, 2014 Cross-cohort comparison (2 cohorts) 2007-2012 New Zealand ↑ depression, emotional problems, hyperactivity, ↓ conduct problems 10-17 years self Global Bor 2014 Systematic review 1990-2010 more countries ↔ externalizing and internalizing problems, ↑ internalizing problems for girls above 12 years 0-18 years parent, teacher, self Collishaw 2014 Systematic review 1970-2012 more countries ↑ emotional problems, ↔ conduct problems and hyperactivity 0-18 years parent, teacher, self ↓ represents a decrease, ↑ represents an increase, and ↔ represents no change Methods Emotional and Behavioral Problem Measure We used the Achenbach System of Empirically Based Assessment (ASEBA), consisting of the Child Behavior Checklist (CBCL) rated by the parent, the Teacher’s Report Form (TRF), and the Youth Self-Report (YSR) (Achenbach, 1991b, 1991c, 1991a, 2001; Achenbach & Edelbrock, 1986, 1987, 1983; Achenbach & Rescorla, 2000), to measure cross-temporal changes in emotional and behavioral problems. All informant versions use a 3-point Likert scale (0 - not true, 1 - sometimes true, 2 - very or often true) for each individual item, with more points indicating more problems. For the eight main problems with behavioral and emotional examples see Table 2. Along with the cross-cultural comparability of the checklist, there is also evidence for the cross-temporal comparability. The checklist exists for 40 years, though subtle changes have been made to the items, from the 120 items of the 1980s, 1990s, and 2000s versions of the CBCL, 114 remained common allowing comparisons over time (Achenbach et al., 2003). Importantly, rank ordering of these item scores produces a high stability ( Q correlation .94-.98) over time. Additionally, for the subscales among versions of the checklist high and very high correlations have been reported based on the comparisons of the Achenbach normative samples in the U.S. from three different decades (Achenbach, 1991b, 1991c, 1991a, 2001; Achenbach & Rescorla, 2000). Findings from the cross-cohort comparison of the CBCL, TRF, and YSR supported the temporal measurement invariance of the rating scale, meaning that the same problems were being measured across time (Achenbach et al., 2002; L. A. Rescorla et al., 2011). In sum, despite some cross-temporal and cross-cultural variation, the evidence shows that the ASEBA rating scales have an empirically based methodology that is robust across diverse cultures and comparable across time, thus making it possible to use in cross-cohort comparisons or cross-temporal meta-analysis (Crijnen et al., 1999; Ivanova et al., 2019; Tick et al., 2007). Table 2 Subscales of the ASEBA Battery with Examples of Items Subscales of the CBCL, TRF, and YSR Examples of Items anxious- depressed fears school, fears certain situations or places, worries a lot, feels worthless, feeling hurt, feels pressure to be perfect, nervous or tense attention problems can’t pay attention for long, restless, hyperactive, impulsive or acts without thinking, talks too much, easily distracted, daydreams, fails to finish, poor school work aggression argues a lot, mean, destroy things, disobedient, gets in many fights, threatens or attacks others, screams, irritable, sudden mood changes, suspicious, temper tantrums, selfish deviant (or rule-breaking) behavior use alcohol/tobacco/drugs, hangs around with other who get in trouble, lacks of guilt, breaks rules, lies, cheats, steals, swears, runs away, sets fire, skips school, vandalism somatic complaints feels dizzy, trouble sleeping (i.e., nightmares), tired, physical problems without a medical cause (e.g., headache, stomachache, vomiting, rashes or skin problems, eye problems), not eating social problems feels lonely, not get along with other kids, easily jealous, teased a lot, not liked by other kids, speech problems, prefer being with younger kids thought problems can’t get mind off certain thought, hears and sees things that aren’t there, repeat certain acts compulsively, sleep less than most kids, strange behavior or ideas withdrawn- depressed spends time rather alone, overtired without a good reason, secretive, rather not talk, acts shy, feeling unhappy, underactive, avoids eye contact, little interest in things around Literature Search A systematic search was conducted in five databases (PubMed, Web of Science, Scopus, EBSCO, Google Scholar) for journal articles in English up until February 2022. The following search string was used: (“CBCL” OR “Child Behavior Checklist” OR “TRF” OR “Teacher Report Form” OR “YSR” OR “Youth Self-Report”) AND (representative OR population-based). The search string was screened in titles and abstracts in four databases, except for Google Scholar where there was no such option, so in that case the full texts of articles were screened with the search string. Moreover, using the snowball method (Sayers, 2008), reference lists of relevant meta-analyses, review articles, and included studies were screened to identify further studies for inclusion. Inclusion and Exclusion of Studies Criteria for studies to be included in this cross-temporal meta-analysis were the following: To explore the changes in emotional and behavioral problems within the last decades, we chose a universally well-known and widely used standardized measurement instrument of such problems among youth, the Child Behavior Checklist (CBCL) 14 . Those studies were included in the meta-analysis which used the parent-reported Child Behavior Checklist (CBCL), the Teacher’s Report Form (TRF), or the Youth Self-Report (YSR), which are different versions of the CBCL designed to be filled in by teachers and youth themselves. Only samples up until the age of 18 years were included. It should be noted that we extended the pre-registered age limit of 14 years in order to cover adolescence as a whole. There was no minimum age limit for the samples, however, the parent-reported CBCL can be used from around 1 year of age. Study samples had to be population-based, meaning that the participants were taken from the general population sharing common characteristics with a probability sampling method such as simple random sampling from the population, systematic sampling, stratified sampling, and clustered sampling, or the mix of these methods. The last inclusion criterion was that studies had to report the raw mean ( M ) and standard deviation ( SD ) for one or more subscales or the Total Problems score of the CBCL, TRF, or YSR. In cases when the M or SD was missing from the article, the first author was contacted through email to provide this data. Studies were excluded in cases when: (1) the items of the subscales were mixed with items from other questionnaires e.g., (Vergunst et al., 2019); (2) the data was incomplete or inappropriate for the analysis due to a missing M or SD e.g., (Ellersgaard et al., 2018); or only z-scores e.g., (Bohlin & Janols, 2004), t-scores e.g., (Kim et al., 2021), prevalence rates were reported e.g.,(Dudani et al., 2010); (3) it was a twin study e.g.,(Whipp et al., 2021); or (4) the sample was not representative of a general population e.g., (Shooshtari et al., 2014). In those cases, when behavioral data were reported for a population-based sample, but the sample was divided into subgroups e.g., picky eaters and non-picky eaters (Machado et al., 2016), means and SD s for all groups were coded and the weighted average was taken. There were cases when large cohort longitudinal data was reported in multiple studies (e.g., Generation R). These cases were reviewed by coders to avoid including the data of the same samples twice in the analysis and the most complete data was chosen. From longitudinal cohorts, a single time point was randomly chosen for each of the age group categories. Studies with year of data collection during or after the COVID-19 pandemic ( k = 3) were excluded from the analysis due to their low number. Lastly, there were only a few studies reporting on the Diagnostic and Statistical Manual of Mental Disorders (DSM) oriented subscales of the CBCL, TRF, or YSR, thus we decided to exclude studies which only reported on these subscales (El Marroun et al., 2014; Mossin et al., 2017; Oerbeck et al., 2020; Otterman et al., 2019; Sondeijker et al., 2007; Zerwas et al., 2014). Coding of Studies Each included study was coded in a standardized coding scheme in regards to (1) emotional and behavioral problems data: the number of participants (n),mean ( M ) and standard deviation ( SD ) of raw scores on all available CBCL, TRF, or YSR subscales and total problems score, (2) outcome information: informant, number of items on the subscale or total score, maximum possible point on the subscale or total score, Cronbach’s alpha coefficients regarding reliability, version of the questionnaire (1981, 1991 or 2001 versions), (3) characteristics of the sample: country and continent of data collection, mean and range of the age of the sample, birth year of the sample which was also categorized into birth cohorts, sex distribution, sampling frame, response rate (the percentage of approached participants who were willing to participate), the ratio of marginalized ethnicities in the sample and (4) the year of data collection. In those cases when the year of data collection was not reported (and could not be retrieved from another study on the same cohort), we subtracted 2 years from the publication year (for a similar procedure see (Buecker et al., 2021; Khan et al., 2021; Protzko, 2020)). In cases when the mean age of the sample was not reported, the two ends of the age range were averaged. When means and SD s were reported separately for boys and girls and for the mixed sex sample as well, we coded the separately reported means and SD s in order to allow for analyses separately for the two sexes. In all other analyses, the combined mean of the two sexes was used. This was true for different age groups as well. When the M or SD was not reported in a study, and those were also not found in other studies reporting on the same cohort, the corresponding authors were contacted to provide the missing data. The selection and coding were done by independent pairs from the two lead authors and a trained group of research assistants. Disagreements in the selection and coding of the studies were resolved by the first author. Data Preparation Firstly, as the CBCL, TRF, and YSR have old and new versions (from 1981, 1991 and 2001) with different maximum points, we calculated the percentage of maximum possible (POMP) scores that obtain comparable scores across studies (Buecker et al., 2021). The maximum possible points on the (sub)scales were coded based on the information written in the individual studies, or if not reported in the study then it was coded based on the referred manual. The POMP scores were calculated with linear transformation of the raw scores ( M and SD ). The following steps were used for the M : (1) subtracting the minimum possible score from the raw mean, (2) subtracting the minimum possible score from the maximum possible score, (3) dividing these previously calculated two scores, (4) multiplying the received quotient by 100. POMP SDs were calculated in a similar manner: (1) subtracting the minimum possible score from the maximum possible score, (2) dividing the raw SD with the previously calculated score, (3) multiplying the received quotient by 100. Higher POMP scores and higher raw means both indicate more emotional and/or behavioral problems. Secondly, as most emotional and behavioral problems on average show age and sex-specific patterns, age and sex were used for categorization to provide more fine-grained analyses of the cross-temporal changes. Based on their mean age, samples were categorized into one of the three age groups (i.e., early childhood from 1 to 6 years, middle childhood from 7 to 14 years, and teens from 15 to 18 years). Additionally, a more fine-grained age grouping was also used for a sensitivity analysis of age groups (i.e., early childhood was divided into toddlers until 2 years and preschoolers from 3 to 6 years, and middle childhood into primary school-age from 7 to 10 years and middle school-age from 11 to 14 years, and teens from 15 to 18 years). Thirdly, as previous evidence on changes in emotional and behavioral problems over time show some cross-national differences among youth, we categorized the included population-based studies on a regional level, based on continents. However, as the total number of included studies for Australian, and African samples were too small to estimate meta-regression coefficients, these continents were not included in the subgroup analysis of continents. Meta-Analytic Procedure Statistical analyses were carried out using the packages `meta` (Schwarzer, 2007) and `metafor' (Viechtebauer, 2021) in the R statistical software (R Core Team, 2021). The statistical analyses followed guidelines from a book about meta-analysis (Harrer et al., 2021). A p -value of less than 0.050 was considered significant. Note, however, that the number of performed hypothesis tests was quite large; hence, false significant results can be present in the study. The size of the effect and the corresponding confidence intervals are most informative. Regarding p -values, in case of a significant result ( p < 0.050), the smaller the p -value, the more unlikely that the significant result is false. We analyzed the CBCL, TRF and YSR problem scale mean values separately. All analyses detailed below are random-effect analyses using restricted maximum likelihood estimators. To analyze the temporal changes in the score means, we used meta-regression analyses. Importantly, there is no effect size computation in a cross-temporal meta-analysis, instead, the change in mean scores on psychological measures is examined among similar-aged groups in different time points of the past (Gonthier & Grégoire, 2022). The coefficient of the predictor year of data collection has a clear interpretation: it shows how much the corresponding score (in the corresponding stratum) changes on average within one year. We visualized the results on regression plots showing the fitted regression line along with the study results. These scatterplots made it possible to check graphically whether the linear usage of the year is adequate or not. Heterogeneity was assessed by calculating I 2 statistics and by reporting Tau , the estimated standard deviation of the random effect term. The fitted random effect meta-model estimates the average true effects of each data year. The random effect term, and hence its estimated standard deviation denoted by Tau , describes the additional random fluctuation of the true effects of the studies. According to the fitted model, ignoring that Tau is just an estimate of the true SD of the random effects, it is roughly true that 95% of the true effects of the studies deviate less than two times Tau from the year-specific average provided by the regression. To assess whether the temporal changes of the scores depended on other moderators (i.e., age group, sex, continent, response rate), we applied stratified exploratory analyses. The reason why we chose stratified analysis instead of using age as a continuous moderator is that in our sample age was a broad category including children from ages 1 to 18 years from very different developmental stages. As far as we know, this can cause aggregation bias in meta-analysis, and analyses in stratified subgroups are advisable (Harrer et al., 2021). Importantly, we chose not to correct for multiple tests is due to the explorative nature of the current study as the number of performed statistical tests is enormous. It is not clear to which subsets we should apply corrections. In this situation, in our opinion, it is a much clearer approach to report the original p-value. If the number of studies was less than 5 in a stratum, we did not perform the meta-regression. In the case of the univariate sex analyses, to take into account that the random effects of the boys' and girls' results within a study are correlated, we fitted a two-dimensional random-effect model (Olkin & Gleser, 2009). We performed influential analysis using the default setting of the influential() function of the metafor R package (Viechtebauer, 2021). It calculates several influential statistics and automatically marks studies as influential if one of the DFFIT, Cook's distance, hat value, or DFBETA statistics indicates a significant influence. We performed a sensitivity analysis by simultaneously leaving out all the studies marked as influential (see supplementary Table S5-S7). Additionally, many sensitivity analyses were performed. Firstly, in multivariate meta-regression models response rate was used as a control variable, in order to identify if the main effect of the year of data collection deviated from the univariate results when controlling for response rate (the percentage of approached participants who were willing to participate). We considered response rate an important control variable because lower response rates can suggest a response bias (i.e., disadvantaged families are usually harder to reach) and potential issues with representativeness. In addition to conducting the analyses regarding the three age groups (early childhood, middle childhood, teens) we repeated these analyses for a finer categorization with five categories (toddlers, preschoolers, elementary school aged children, middle school aged children, teens). However, as there were not much deviations in the results and the analyses with three categories have more statistical power, results regarding the five categories are only reported in the Supplemental Materials (see Table S2). In order to assess potential differences due to the three different versions of the CBCL, we performed supplementary analyses excluding the version from 1981, as there were substantially fewer studies using the earliest version of the CBCL. Further, analyses were also performed to test the differences between the 1991 and the 2001 version of the CBCL, TRF, and YSR by (see Table S3), and the cross-temporal changes only with the 2001 version of the CBCL, TRF, and YSR was also supplementary tested (see Table S8). These separate analyses also served as a simple non-linearity check, complementing the visual check of the scatterplots. Lastly, in response to reviewer feedback, we conducted simple regressions to assess (1) whether the reliability of the subscales changed over the years and if reliability was related to the means and (2) whether the ratio of marginalized ethnic minorities in the sample was related to the means. Transparency and Openness We adhered to the PRISMA 2020 guidelines for systematic reviews (Page et al., 2021). Data, analysis code, and supplementary analysis plots are available at the repository linked below the data availability statement. Data were modeled using the packages `meta` (Schwarzer, 2007) and `metafor' (Viechtebauer, 2021) in the R statistical software (R Core Team, 2021). This review project was pre-registered at [link removed for masked review] . There were some small deviations from the pre-registration protocol, for instance in the search string, that are disclosed in the supplementary (see Table S1 ). Additionally, in October 2023, an updated and expanded systematic search was performed by removing „representative or population-based” and using „epidemiol*” and „populat*” instead in response to reviewer requests. This second systematic search was conducted in all previously searched databases except for Google Scholar. The PRISMA flow diagram shows both systematic search processes, with the first one identifying 100 eligible studies, and the second one with 75 additional studies, resulting in a sum of 175 studies (see Figure A1). Results Descriptive Statistics In total, 175 included studies, with most studies reporting parent-reported externalizing problems for the combined age analysis (with 1-18 year olds; k = 100), followed by internalizing ( k = 97), and total problems ( k = 74). There were34 studies for self- and 24 for teacher-report of externalizing problems, with a similar number of studies for internalizing and total problems. Earliest data was from 1981 and latest from 2021. The lowest number of studies were from the 1980s ( k = 10), then the 1990s ( k = 48), with the most from the 2000s ( k = 65). The majority of the studies included samples from European countries ( k = 91), followed by North and South American ( k = 41), Asian ( k = 30), Australian ( k = 7), and African ( k = 3) countries. The countries with the most data collection points were the Netherlands in Europe, the U.S. in North and South America, and China in Asia (see Table S4 for the year of data collection points by country). The average age of the samples was 10.87 years ( SD = 4.12), ranging from 1 to 18 years. Reliability of the Subscales Cronbach alpha for the subscales and/or the total score was reported in 76/175 primary studies and ranged between 0.27 and 0.98. Internal reliability did not show any significant changes over the years except for a significant decrease in the reliability of parent-reported attention problems ( k = 16, b year = -0.005, p = .005) and deviant behaviour ( k = 18, b year = -0.008, p = .033) (for scatter plots see the OSF link under the Data Availability statement). Reliability estimates of parent-reported attention problems, in turn, had a significant, negative relationship with the means of parent-reported attention problems with studies reporting better reliability showing smaller scores. This was not the case for deviant behaviour. Thus measurement invariance seems to be problematic in the case of the parent-reported attention problem subscales and it might have affected the results regarding this subscale. Univariate Differences in Emotional and Behavioral Problems There were a few significant differences in mean emotional and behavioral problems within subgroups of continents (Europe, America, Asia) and age groups (early, middle childhood, teens), and several differences of sexes (girls, boys) and response rates revealed by univariate analysis. The significant differences are summarized and written in bold in Table A2-4. The ratio of marginalized ethnic minorities in the samples was reported for almost half (53%) of the studies. The ratio of marginalized ethnic minorities had significant, positive relationships with the amount of aggression reported by teachers, thought problems reported by both parents and self-reports, and total problems reported by parents (for scatter plots see the OSF link under the Data Availability statement). However, the ratio of marginalized ethnicities did only show significant changes in case of self-reported anxiety-depression with a decrease over the years ( k = 11, b year = -1.782, p = .048). Changes in Total Emotional and Behavioral Problems Table A5 gives an overview and Table A6-A16 gives detailed results from the stratified analysis by informant, age group, sex, and continent, and shows those cases where the analysis was not conducted due to a low number of studies. Importantly, there were many cases where the study number was low, especially for continental results by age groups. Analyses controlling for response rate are also presented in the previously mentioned tables. The results of the sensitivity and supplementary analyses and the models excluding influential cases are shown in the supplemental materials (Table S2-S5). All scatterplots and heterogeneity analysis are shared through the OSF link under the Data Availability statement. The I 2 were substantially high in almost all cases (<90%), heterogeneity ( Tau ) is reported for the significant analysis. The univariate meta-regressions showed no change in total emotional and behavioral problems of youth over the last 40 years according to parent reports. When response rate was controlled, parent reported total problems decreased over the last four decades among early childhood samples ( k = 20, b year = -0.22, p = .029, 95%CI[-0.41,-0.03], Tau = 3.19) and among European samples of children in middle childhood ( k = 21, b year = -0.09, p = .047, 95%CI[-0.18,0], Tau = 1.5). Similarly, teacher reports showed no change in total problems of youth overall, however, the sensitivity analysis excluding the study that used the 1980s version, showed a significant decrease over the last 30 years ( k = 22, b year = -0.17, 95%CI[-0.32,-0.02], p = .033). Similarly, a decrease in teacher reported total problems was detected in middle childhood among European samples ( k = 9, b year = -0.12, p = .030, 95%CI[-0.22,-0.02], Tau = 0.96), which was similar in magnitude but no longer statistically significant when response rate was included in the model. Thus, according to direct measures from parents and teachers, children have either had fewer or the same number of total problems since the 1980s. Meta-regression analyses of self-reports of total problems of youth showed mixed results. There was a significant increase in total problems overall ( k = 28, b year = 0.22, 95%CI[0.02,0.42], p = .029), however, this effect was substantially reduced and not significant when response rate was controlled for. When analyzing age groups separately, there was no change in self-reported total problems over the last decades among middle childhood samples, yet, when response rate was partialed out it showed a significant decrease with time ( k = 8, b year = -0.33, p = .029, 95%CI[-0.61,-0.05], Tau = 1.49). Among teens, the univariate analysis of self-reports detected a significant increase with year of data collection ( k = 18, b year = 0.29, 95%CI[0.01,0.57], p = .046, Tau = 3.8). This effect was similar in size but no longer significant when response rate was controlled for. In the same vein, when influential cases ( k = 2) were excluded, the effect became non-significant. On the other hand, a significant decrease was found among teenage boys based on self-reports, but only when response rate was controlled for ( k = 11, b year = -0.57, p = .032, 95%CI[-1.08,-0.06], Tau = 2.23). Changes in Externalizing Problems There were no significant changes in externalizing problems overall. However, we found a significant decrease in middle childhood based on parents’ ( k = 60, b year = -0.21, p < .001, 95%CI[-0.30,-0.11], Tau = 3.29) over the last 40 years (see Figure 1). The effect was very similar in size when we controlled for response rate. This decrease in middle childhood was confirmed when inspecting parents’ reports in North and South America ( k = 16, b year = -0.21, p = .030, 95%CI[-0.40,-0.03], Tau = 3.41), which effect was the same in size but no longer significant when response rate was controlled for. The decrease in middle childhood was also confirmed in parent reports in Europe ( k = 30, b year = -0.20, p = .028, 95%CI[-0.38,-0.02], Tau = 3.78), which effect was still significant when response rate was controlled for, however, when we excluded the two studies using the oldest version of the CBCL in a sensitivity analysis, the effect was substantially reduced and no longer significant. Again, the decrease in middle childhood based on parental reports was also confirmed in samples of boys ( k = 29, b year = -0.38, p < .001, 95%CI[-0.59,-0.17], Tau = 3.65) and girls ( k = 29, b year = -0.43, p = .001, 95%CI[-0.68,-0.18], Tau = 4.22), even when controlling for response rates. Additionally, self-reported externalizing problems of girls in middle childhood also showed a significant decrease when response rate was included ( k = 5, b year = -0.55, p = .024, 95%CI[-0.96,-0.14], Tau = 0.64). However, this result should be interpreted with caution because the supplementary analysis of the difference between the 1991 and 2001 versions of the YSR showed that studies using the 1991 version of the questionnaire found higher scores than the ones using the 2001 version over a crossover period between 2001-2010 when both versions were used in studies. Among teenagers, there was a significant decrease in externalizing problems based on parental reports ( k = 16, b year = -0.29, p = .045, 95%CI[-0.57,-0.01], Tau = 3.60), which was very similar in size but no longer significant when response rate was controlled for, or when the only study using the version of the CBCL from the 1980s was excluded in a sensitivity analysis. Furthermore, when influential cases were excluded ( k = 1), the effect became non-significant. A decrease in parent reported externalizing problems was confirmed in samples of teenage boys ( k = 12, b year = -0.27, p = .049, 95%CI[-0.54,0], Tau = 2.50), which remained after controlling for response rate. These results suggest between 2 and 6 points decrease every 10 years in externalizing problems. Interestingly, in early childhood there were no significant changes in externalizing problems, however, the sensitivity analysis without the one study using the version of the CBCL from the 1980s showed a significant increase among both boys ( k = 12, b year = 0.89, 95%CI[0.17,1.61], p = .021) and girls ( k = 12, b year = 0.82, 95%CI[0.17,1.47], p = .019). Although, this might be due to a major change in the 2001 version of the CBCL for young children (1.5 to 5 years) compared to the 1991 version, as externalizing problems were extended with attention problems in the 2001 version, but only for this young age group. When we inspected the results only regarding the 2001 version of the CBCL, the effect size was similar but did not reach significance. Changes in Aggression There were no significant changes in aggression overall. However, we found a significant decrease over the last 40 years in middle childhood based on parental reports ( k = 47, b year = -0.18, p = .009, 95%CI[-0.31,-0.05], Tau = 4.47 ) and self-reports ( k = 9, b year = -0.41, p = .006, 95%CI[-0.66,-0.16], Tau = 3.27) (see Figure 2), both of which remained significant when controlling for response rate. The decrease in parent-reported aggression among children in middle childhood was confirmed in South and North American samples ( k = 16, b year = -0.24, p = .028, 95%CI[-0.45,-0.03], Tau = 4.25), which was similar in size but no longer statistically-significant when response rate was controlled for. It was also confirmed in European samples when response rate was included in the model ( k = 14, b year = -0.27, p = .042, 95%CI[-0.53,-0.01], Tau = 2.95). A decrease in parent-reported aggression in middle childhood among girls also appeared ( k = 22, b year = -0.27, p = .008, 95%CI[-0.46,-0.08], Tau = 3.35), however, this effect was substantially reduced and no longer significant when considering response rate. Finally, there was a decrease in self-reported aggression of teenage boys when response rate was partialled out ( k = 10, b year = -1.06, p < .001, 95%CI[-1.76,-0.36], Tau = 5.03). These trends suggest about 2 to 10 points of decrease in aggression problems every 10 years. Changes in Deviant Behavior Univariate meta-regressions showed a significant decrease in teacher-reported deviant behavior ( k = 15, b year = -0.22, p = .042, 95%CI[-0.43,-0.01]), which effect was substantially reduced and no longer significant when response rate was included. Parent report showed a similar decrease of youth’s deviant behavior but only when controlled for response rate ( k = 40, b year = -0.19, p = .042, 95%CI[-0.37,-0.01]). A significant decrease was detected in middle childhood based on parent report when response rate was controlled for ( k = 33, b year = -0.15, p = .009, 95%CI[-0.26,-0.04], Tau = 2.25), and also based on teacher report ( k = 15, b year = -0.22, p = .035, 95%CI[-0.42,-0.02], Tau = 2.93), however, this effect was reduced and no longer significant when response rate was taken into account. Additionally, when excluding influential cases ( k =1), the effect became non-significant. A significant decrease of deviant behavior was found in Asia among middle childhood samples ( k = 13, b year = -0.14, p = .045, 95%CI[-0.28,0], Tau = 1.95) but, again, this effect was smaller and no longer significant next to response rate and became non-significant when influential cases were excluded. Changes in Internalizing Problems There were no significant changes in internalizing problems overall. Results among early childhood samples showed mixed results. A decrease in internalizing problems was found based on parental reports of both boys ( k = 8, b year = -0.58, p = .037, 95%CI[-1.11,-0.05], Tau = 4.32) and girls ( k = 8, b year = -0.53, p = .040, 95%CI[-1.03,-0.03], Tau = 4.06) when response rate was included in the models, but the sensitivity analysis without the only study using the oldest version of the CBCL from the 1980s changed the direction of the effect size and showed significant increases in parent reported internalizing problems of boys ( k = 9, b year = 0.46, p = .042, 95%CI[0.02,0.9]) and girls ( k = 9, b year = 0.47, p = .028, 95%CI[0.07,0,87]). There was a significant decrease in middle childhood based on parents’ report ( k = 60, b year = -0.10, p = .033, 95%CI[-0.18,-0.01], Tau = 2.99), but this was no longer statistically-significant when response rate was controlled for or when studies using the oldest version of the CBCL ( k = 5) were excluded. This was also confirmed when the effect became non-significant when influential cases ( k = 3) were excluded. The same decreasing tendency was confirmed in middle childhood samples of both boys ( k = 29, b year = -0.22, p = .036, 95%CI[-0.42,-0.02], Tau = 3.96) and girls ( k = 29, b year = -0.19, p = .046, 95%CI[-0.38,0], Tau = 3.63), again, even after controlling for response rate, but no longer significant when studies using the oldest version of the CBCL were excluded ( k = 5). Additionally, when excluding influential cases ( k = 2), the effect for boys became non-significant. Finally, a significant decrease was found in internalizing problems among European samples of children in middle childhood based on teacher reports ( k = 9, b year = -0.17, p = .038, 95%CI[-0.33,-0.01], Tau = 1.26), which remained when controlling for response rate. Similarly, significant decreases were detected among teenage boys ( k = 12, b year = -0.32, p = .044, 95%CI[-0.06,-0.01], Tau = 3.93) and girls ( k = 12, b year = -0.33, p = .042, 95%CI[-0.65,-0.01], Tau = 3.05) based on parents’ report, which effects remained when response rate was included in the models, but were no longer significant when the studies using the oldest version of the CBCL from the 1980s were excluded in the sensitivity analysis. Additionally, when excluding influential cases ( k = 2), effect for both boys and girls became non-significant. Changes in Anxiety-Depression There was no significant change in anxious-depressed problems overall. However, a significant decrease was shown in early childhood in Asia based on parents’ report ( k = 5, b year = -0.64, p = .010, 95%CI[-0.99,-0.29]). In contrast, global parent reports showed an increase in anxiety-depression among teens ( k = 12, b year = 0.26, p = .011, 95%CI[0.07,0.45], Tau = 1.96) (see Figure 3), which remained even after controlling for response rate. This increasing trend in anxiety based on parent reports was confirmed in European teen samples ( k = 9, b year = 0.28, p = .030, 95%CI[0.04,0.52], Tau = 2.27), which effect was similar in size but no longer statistically-significant when response rate was taken into account. Changes in Somatic Complaints Overall, no change was detected in somatic complaints over the last 40 years. However, we found an increase in self-reported somatic complaints in teenage boys (k = 12, b year = 0.61, p < .001, 95%CI[0.34,0.87], Tau = 2.95), which effect remained significant but substantially reduced when response rate was controlled for. No other subgroups showed significant changes (see Table A12). Changes in Withdrawn-Depression Overall, there was a significant decrease in withdrawn-depressed behavior based on self-report but only when response rate was partialled out (k = 20, b year = -0.28, p = .023, 95%CI[-0.52,-0.04]). A decrease with year of data collection was also detected for parent reports in middle childhood but only when response rate was controlled for ( k = 34, b year = -0.15, p = .039, 95%CI[-0.29,-0.01], Tau = 3.39), which was also confirmed for samples of girls ( k = 18, b year = -0.34, p = .044, 95%CI[-0.67,-0.01], Tau = 3.43). A decrease with year of data collection was also shown in parent reports of Asian samples in early childhood (k = 5, b year = -0.27, p = .040, 95%CI[-0.52,-0.02], Tau = 0.86), however, when influential cases were excluded ( k = 1), the effect became non-significant. Changes in Attention Problems A significant increase in attention problems with year of data collection was detected based on parent reports ( k = 63, b year = 0.24, p = .004, 95%CI[0.08,0.40]) (see Figure 4), which remained significant when response rate was controlled for. However, as mentioned above we found a decreasing reliability of parent-reported attention problems over the years and these reliability estimates were negatively related to the means on parent-reported attention problems. This suggests that the observed increase in parent-reported attention problems over the years might be explained by the issue of measurement variance. When analyzing age groups and sexes separately, we found a significant increase in attention problems in middle childhood boys ( k = 24, b year = 0.29, p = .031, 95%CI[0.03,0.55], Tau = 4.00), which effect remained when response rate was partialled out. Controversially, teacher reports of attention problems in middle childhood showed a decreasing trend with time for both boys ( k = 8, b year = -0.65, p = .003, 95%CI[-0.98,-0.32], Tau = 2.34) and girls ( k = 8, b year = -0.56, p = .033, 95%CI[-1.06,-0.06], Tau = 3.56), and these were similar when response rate was included in the models, although no longer statistically-significant in the case of girls. Additionally, it should be noted that continent was a confound here: all studies in these analyses were from Europe from the earlier years, and from North or South America in the later years. This might explain the difference between the trends based on parent and teacher reports. Changes in Social Problems Overall, there was a significant increase with time in self-reported social problems of youth (k = 26, b year = 0.33, p = .029, 95%CI[0.11,0.85]), however, the effect size was reduced substantially and not significant when response rate was controlled for. This increase was significant for teens ( k = 19, b year = 0.48, p = .013, 95%CI[0.11,0.85], Tau = 5.68), however, it was substantially reduced and no longer statistically-significant when response rate was also taken into account. This significant univariate increase in self-reports was also confirmed in teenage boys ( k = 12, b year = 0.68, p = .003, 95%CI[0.29,1.07], Tau = 4.38) and girls ( k = 13, b year = 0.63, p = .035, 95%CI[0.05,1.21], Tau = 6.89), however, these effects were substantially reduced and no longer statistically-significant when response rate was controlled. Additionally, when excluding influential cases, the effects became non-significant for both boys and girls. The only increase in self-reported social problems of teens that remained after controlling for response rate was found in European samples ( k = 16, b year = 0.67, p = .001, 95%CI[0.32,1.02], Tau = 2.19). Thus, there may be an increase in social problems over time, but the results may not be robust to methodological differences and response rate. Changes in Thought Problems Thought problems showed an increasing trend over the last decades according to parent-report ( k = 40, b year = 0.09, p = .006, 95%CI[0.03,0.15]) (see Figure 5), which remained even when response rate was controlled for. Self-reports of thought problems also showed an increasing tendency over time among the overall youth sample ( k = 24, b year = 0.47, p = .044, 95%CI[0.01,0.93]), but this effect was substantially reduced and no longer statistically-significant when response rate was partialled out. We found a significant increase in parent reported thought problems in middle childhood samples ( k = 35, b year = 0.07, p = .046, 95%CI[0,0.14], Tau = 1.78), which was confirmed in European samples ( k = 13, b year = 0.13, p = .044, 95%CI[0,0.26], Tau = 1.63). These effects were similar but no longer significant when response rate was included in the models. A similar increase was also found among European teenagers based on parent-report, which was only significant when response rate was also taken into account ( k = 8, b year = 0.14, p = .030, 95%CI[0.02,0.26], Tau = 0.87). Self-report data of teens globally also showed an increase ( k = 19, b year = 0.74, p = .009, 95%CI[0.21,1.27], Tau = 8.19), however, this effect was substantially reduced and no longer significant when response rate was controlled for. Additionally, when influential cases were excluded, the effect became non-significant. This pattern was confirmed in European samples. When interpreting these results it should also be noted that self-report data on thought problems were found to be biased by whether the 1991 or 2001 version of the CBCL was used: studies in the crossover period of 2001-2010 using the latter found larger scores on average. This might be explained by the change in the instrument because the thought problem subscale of the 2001 version also includes items regarding self-harm. Upon closer inspection, self-report data using neither the 1991, nor the 2001 version showed no changes over time in teens. Thus, there may be increases in thought problems, but the results are not robust to methodological differences and response rate or version of the scale used. Discussion Findings of this cross-temporal meta-analysis of 175 included studies from around the world (44 countries) covering four decades between 1981–2019 show there are very few robust changes in the mean-level of subclinical emotional and behavioral problems. In the mean-level of total problems, we found no evidence of change either based on reports of parents, teachers or youth themselves. However, stratified analysis by age groups and sexes, controlled for response rate (and thus for a possible representativeness bias), showed decreases in total problems for some groups: in early childhood (based on parent ratings), among teenage boys’ (based on self-report) and in middle childhood European samples (based on teacher reports). Thus, where there were changes in total problems, they were often seen as improvements rather than deterioration over time. These findings indicate that ‘kids these days’ are not facing more mental health problems, moreover, recent generations might be experiencing slightly better mental health than young people four decades ago. The lack of change in total behavioural and emotional problems seems to support the prevalence inflation hypothesis (Foulkes & Andrews, 2023) that an increase in mental health disorders is due to increasing awareness of mental health disorders as opposed to an actual increase in these mental health problems. If mental health disorders were truly on a rise, so should be the anteceding behavioural and emotional problems during childhood. Instead, based on the results of the present study it seems that the increase in mental health disorder diagnoses might be due to increased awareness of these disorders and more likelihood of receiving the diagnosis. These findings align with those of a recent Canadian longitudinal time-lag study, which found no overall increase in mental health problems across the past two generations, although the proportion of youth at risk for a “mental health crisis” was increasing (Borg et al., 2025). A key finding from our meta-analysis, supported by converging evidence from multiple informants, was a decrease in externalizing problems, particularly aggression during middle childhood, based on both parent reports and self-reports, as well as a decline in self-reported aggression among adolescent boys. These positive changes in young people’s mental health might be explained by complex socio-cultural and environmental changes over the last decades, for instance: (1) increasing living standards of families and a rise in parents’ educational level (Our World in Data, 2016, 2018); (2) rising public investments in prevention and intervention programs in schools or community services (e.g., social-emotional learning programs decrease externalizing problems) (Cox, 2005; Farrington & Welsh, 2008); (3) rising public awareness and reduced stigma towards mental disorders (Evans-Lacko et al., 2014; Pescosolido et al., 2021); (4) increased parental warmth (Collishaw et al., 2010; Garcia et al., 2020); (5) rising levels of child-care time, child-centered and time-intensive parenting (e.g., more time invested in children either spent together or organizing extracurricular activities) (Dotti Sani & Treas, 2016; Ishizuka, 2019; Schiffrin et al., 2015); and (6) a decrease of physical punishment in parenting practice from the 80’s (Durrant & Ensom, 2012; Wiggers & Paas, 2022). It is important to note, however, that the ASEBA battery measures offline physical and verbal aggression; it does not include cyberbullying, which may represent a form of aggression that has not declined over the past decades. Importantly, there were no convergent opinions between parents, teachers and young people, about changes in other problems, such as attention problems, thought problems, anxiety-depression, social problems, or somatic complaints. However, we have to note here that opinions were not divergent (except for attention problems), but data from one informant indicated a change, while the other showed stability over time. Previous studies on secular changes also reported different opinions of informants (Maughan et al., 2008; Tick et al., 2007). Cross-informant discrepancies might display that there are genuine differences in young people’s behavior in a given social context and problems occur to be context-specific (e.g., a problem is present only at home or in the presence of the parent) (De Los Reyes et al., 2013). Alternatively, informants’ concepts of what constitutes these behavioural and emotional problems might have shown different changes over the last decades. We found single-informant evidence of increases (parent reports: attention problems and thought problems for youth overall, anxiety-depression for teens; self-reports: somatic complaints of teen boys) and decreases too (parent reports: externalizing problems in middle childhood; self-reports: aggression of teen boys). These should be interpreted with caution considering that data only from one informant reflected such a change. Firstly, the potential rise in thought problems indicates that parents report more symptoms like intrusive thoughts, compulsive behavior, disorganized thinking, disturbed sleep, strange behaviors or ideas, and delusions, in more recent generations of young people. Importantly, from 2001 the ASEBA battery includes a self-harm related item in the thought problems subscale, which could also contribute to the slightly rising numbers, as self-harm and suicide has been reported to increase in many countries since the 2000s (Griffin et al., 2018; Twenge, 2020; Universities UK, 2018). Various socio-cultural and environmental factors have been reported in previous studies that might explain this increasing tendency in parent-reported thought problems over the last decades: (1) increase in parental conflict or divorce, which can contribute to ruminative and self-critical thoughts (Raley & Sweeney, 2020; Schmuck, 2013; Zalewski et al., 2012); (2) increase in loneliness and reduced interaction with other can lead to distorted thinking and detachment from reality (Buecker et al., 2021; Twenge et al., 2019); and (3) increase in media (especially social media) use and unrealistic expectations (Twenge et al., 2019; Vuong et al., 2021). If future studies also confirm an increasing tendency in thought problems in recent and future generations of young people, we list some examples of skills that have been reported to have a positive effect on thought problems: self-regulation (Atta et al., 2024), positive thinking (Davoodi et al., 2024; Rood et al., 2012), cognitive flexibility (Y. Yang et al., 2017), problem solving (Watkins & Baracaia, 2002), self-compassion and mindfulness (Hilt & Pollak, 2012; Perestelo-Perez et al., 2017). In case such an increasing tendency is confirmed in future research, we would like to encourage both parents and educational institutions to consider nurturing these skills and strategies that can reduce thought problems and the closely associated mental health disorders (e.g., anxiety, depression). Secondly, we also found evidence for an increase in parent reported anxiety-depression among adolescents and in self-reported somatic complaints of boys. There was no strong evidence for a change in withdrawn-depressed behavior. However, we have to note that there was an increase among European teenagers self-reported withdrawn-depression between 2001–2019, although the study number was relatively small. These findings are partly congruent with many studies from worldwide reporting a rise in emotional problems of adolescents over the last decades (Armitage et al., 2024; Collishaw, 2015; Hölling et al., 2014; Su & Liu, 2020; Twenge, 2020). The rise in adolescent’s emotional problems could be explained by the following examples of socio-cultural and environmental changes over the last decades: (1) increase in parental emotional problems (Schepman et al., 2011); (2) increase in technology use and screen time (in 2008 average screen time/week of an adolescent overcame active leisure time such as physical activity, arts, writing, reading and socializing), which has been directly linked to anxiety, somatic complaints, and depression (Sawhill, 2016; Twenge et al., 2018); and (3) increase in cyberbullying victimization that is linked to negative self-perception and altered impulse control (Evans-Lacko et al., 2017; Kennedy, 2021). Based on previous evidence and our findings about the increase in emotional problems, recent generations of teenagers, especially boys for whom somatic complaints are also on the rise could benefit from nurturing skills such as stress management (Sahranavard et al., 2018; Yazdani et al., 2010), mindfulness (Call et al., 2014), or emotional intelligence (Fernandez-Berrocal et al., 2006). Thirdly, we found some evidence for an increase in social problems of European teenagers (based on self-report). Yet, no study reported about recent cross-temporal changes in social problems in European samples, thus we highly recommend future studies to investigate this, as the social isolation due to the COVID-19 pandemic could have further worsened these symptoms. Fourthly, we also found evidence for a rise in parent-reported attention problems for children and adolescents, however, this might be due to a problem with measurement invariance of the CBCL’s subscale as we found a decrease in the reliability of this subscale over the years. Moreover, reliability was negatively related to the mean attention problems reported. For future studies improving the factor structure of the CBCL, the items of this subscale might need an update so that they can reliably measure attention problems of more recent generations. Additionally, teacher reports showed the opposite: a decrease in attention problems. It should be noted though that there was a low number of studies in case of teacher reports, and the results seemed to have been confounded by the continent where data was collected. Future studies should examine how parents’ and teacher’s ratings regarding children’s attention problems have changed over the last decades as we cannot draw strong conclusions here. In sum, the only strong evidence for a change reflected a decrease in externalizing problems, especially aggression. For potential changes for which we found some evidence, the patterns were a mix of increases and decreases, and often not robust to methodological checks. For the most analyses, however, we found null results. In sum, our results do not support concerns regarding that kids these days are more problematic. Instead, these results suggest that the level of behavior and emotional problems in total is constant over time but there is a variation in the way young people (and their parents) experience problems: kids in the last decade seem to experience less externalizing problems which involve conflict and interaction with the social environment, but potentially more internalizing problems which reflect inner distress. Overall, it is tempting to think things are getting worse. Such complaints of generational decline are ever present and a long-standing trope. Even experts mispredict secular changes in their own field highlighting the presence of researcher misconceptions (Grossman et al., 2024). This does not mean that temporal changes do not occur, but the default belief should not be declined, especially without evidence. In addition, an increase in mental health disorders has been proposed to potentially reflect an increasing awareness of these disorders and the corresponding larger likelihood that one received the diagnosis as opposed to an increase in people experiencing such mental health disorders (Foulkes & Andrews, 2023 ). We tried to contribute to the evidence on whether change is actually occurring in the mental health of our societies by focusing on the antecedent of mental health disorders: behavioural and emotional difficulties in childhood and adolescence. We found little reliable change in behavioural and emotional symptoms for children since the 1980s. We urge caution for researchers to believe change is occurring without evidence, and our evidence here is only one part of a larger discussion. Limitations Importantly, there are limitations of the present study. First of all, null results should be interpreted with caution. The present paper reports exploratory analyses in which we conducted many analyses, including ones on small sets of studies, which might have resulted in low statistical power in these cases. On the other hand, due to the fact that we conducted a large number of analyses, we cannot exclude the possibility of some incidental significant results just due to chance, which would only further heighten the fact that the majority of results show no significant change in behavior problems since the 1980s. Additionally, findings of this cross-temporal meta-analysis explored a longer time frame compared to many previous studies, this could result in no detectable change as rises and falls could cancel each other out. Although, we would like to highlight that it is also important to look at short-term (e.g., 5 years) rises in emotional and behavioral problems, as these can influence policy making (e.g., intervention programs) to target a certain problem. Importantly, another limitation was that the post COVID-19 period (from 2019) was not included in this cross-temporal meta-analysis due to a limited number of studies, and the pandemic might have had a substantial negative impact on children and adolescents mental health (Panchal et al., 2023). Another limitation was that heterogeneity was substantially high for all analysis. However, the I 2 estimate generally used for the measurement of heterogeneity have been proposed to be somewhat imprecise in case of meta-analysis of cohort and population-based studies as due to the large sample sizes, and within-study variation the I 2 can be large (> 75%) even if the between-study variation is small (Coory, 2010). Although, the standard deviation of the random effect term (Tau) also showed large variations of the effect sizes among studies. In the light of this, we would like to highlight that the changes can vary by countries, certain groups of youth, or even individuals. Previous researchers caution about drawing conclusions from the individual based on population-level or ecological data, that is the so-called aggregation bias or ecological fallacy (Robinson, 1950). Along with this, it is important to highlight that there were countries with much more data collection points than other countries from each continent, for instance the Netherlands from Europe, the USA from North and South America, and China from Asia. These countries could influence the continental results. Connected to the multicultural comparison in the current meta-analysis, it is important to mention that from the ASEBA battery, only the YSR have been tested for measurement invariance across multiple cultures (Stevanovic et al., 2017), thus we cannot exclude the possibility that the parent and teacher reported versions might have measurement noninvariance across cultures. This is also true within cultures but over time. It could be that certain items are noninvariant, and operate differently across time. Without the raw item-level data, measurement invariance cannot be tested, unfortunately. If behavior problems (latent) are increasing, but certain items (or raters) are operating differently and decreasing, true changes could be masked. There is an ongoing need to track changes in the subclinical level of emotional and behavioral problems with standardized questionnaires in recent cohorts of young people. In the future with moves towards standardisation of scales/measures (e.g., the Wellcomes ‘Common metrics in mental health research’ guidance), and possibly linked health records, there may well be other opportunities to measure or triangulate with. Lastly, it may not be excluded that increases and decreases reflect whether informants’ reports have changed over the years as expectations or tolerance for different types of behavior have also changed. However, there is a gap in the literature about possible changes in reporting biases, which might be very hard to quantify. Conclusion In conclusion, between 1981-2019, our data suggest that children have not been in general decline in deviant, aggressive or mentally unhealthy behaviors. The most robust changes are actually improvements in externalizing behavior, specifically aggression. At the same time, changes in emotional and behavioral problems showed some differences according to age levels, sexes, continents, and informants that we presented in exploratory analyses in the present study. These findings indicate that kids these days have different challenges: specifically children and adolescents regarding thought problems (and perhaps attention problems), and teenagers need more support regarding anxiety and depression. Overall the results do not support concerns regarding a genuine decline in young people’s mental health. Declarations Data availability The datasets, all scatterplots and heterogeneity analysis generated for the meta-analysis are available in the Open Science Framework repository, https://osf.io/9yzjs/?view_only=fa6a705b8a2c4482911dc3d5c5fcd8f6. Code availability The R code created for the meta-analysis is also available in the Open Science Framework repository, https://osf.io/9yzjs/?view_only=fa6a705b8a2c4482911dc3d5c5fcd8f6. Author Contribution B.V., Z.K.T., A.L., and J.P. contributed to the planning of the project. B.V. and Z.K.T. performed the systematic search, the inclusion process and the coding of the studies. T.K. performed the statistical analysis. W.H.C. helped in the revision of the introduction and discussion of the paper. The manuscript was revised by all authors. Acknowledgement B.V. received funding for this work from the ÚNKP-22-4 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. Declaration of interests ☐ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☒ The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: References References marked with an asterisk indicate studies included in the meta-analysis. *Achenbach, T. M. (1991a). Child behavior checklist/4–18. University of Vermont . Achenbach, T. M. (1991b). Manual for the Teacher’s Report Form and 1991 Profile . University of Vermont, Department of Psychiatry. Achenbach, T. M. (1991c). Manual for the Youth Self-Report Form and 1991 Profile . University of Vermont, Department of Psychiatry. Achenbach, T. M. (2001). Manual for ASEBA school-age forms & profiles. University of Vermont, Research Center for Children, Youth & Families . Achenbach, T. M., Dumenci, L., & Rescorla, L. A. (2002). Ten-year comparisons of problems and competencies for national samples of youth: Self, parent, and teacher reports. Journal of Emotional and Behavioral Disorders , 10 (4), 194–203. Achenbach, T. M., Dumenci, L., & Rescorla, L. A. (2003). Are American children’s problems still getting worse? A 23-year comparison. Journal of Abnormal Child Psychology , 31 (1), 1–11. Achenbach, T. M., & Edelbrock, C. (1986). Manual for the Teacher’s Report Form and Teacher Version of the Child Behavior Profile . University of Vermont, Department of Psychiatry. Achenbach, T. M., & Edelbrock, C. (1987). Manual for the Youth Self-Report and Profile . University of Vermont, Department of Psychiatry. Achenbach, T. M., & Edelbrock, C. S. (1983). Manual for the child behavior checklist and revised child behavior profile. (No Title) . Achenbach, T. M., & Rescorla, L. A. (2000). Manual for the ASEBA preschool forms and profiles (Vol. 30). Burlington, VT: University of Vermont, Research center for children, youth …. *Ahmad, A., Abdul-Majeed, A. M., Siddiq, A. A., Jabar, F., Qahar, J., Rasheed, J., & von Knorring, A.-L. (2007). Reporting questionnaire for children as a screening instrument for child mental health problems in Iraqi Kurdistan. Transcultural Psychiatry , 44 (1), 5–26. https://doi.org/10.1177/1363461507074949 *Ajduković, M., Rajhvajn Bulat, L., & Sušac, N. (2018). The internalising and externalising problems of adolescents in Croatia: Socio‐demographic and family victimisation factors. International Journal of Social Welfare , 27 (1), 88–100. https://doi.org/10.1111/ijsw.12284 *Alati, R., Najman, J. M., O’Callaghan, M., Bor, W., Williams, G. M., & Clavarino, A. (2009). Fetal growth and behaviour problems in early adolescence: Findings from the Mater University Study of Pregnancy. International Journal of Epidemiology , 38 (5), 1390–1400. *Albaugh, M. D., Nguyen, T.-V., Ducharme, S., Collins, D. L., Botteron, K. N., D’Alberto, N., Evans, A. C., Karama, S., Hudziak, J. J., & Brain Development Cooperative Group. (2017). Age-related volumetric change of limbic structures and subclinical anxious/depressed symptomatology in typically developing children and adolescents. Biological Psychology , 124 , 133–140. *Alvarenga, P. G., Do Rosario, M. C., Cesar, R. C., Manfro, G. G., Moriyama, T. S., Bloch, M. H., Shavitt, R. G., Hoexter, M. Q., Coughlin, C. G., & Leckman, J. F. (2016). Obsessive–compulsive symptoms are associated with psychiatric comorbidities, behavioral and clinical problems: A population-based study of Brazilian school children. European Child & Adolescent Psychiatry , 25 (2), 175–182. *An, S., Rauch, S. A., Maphula, A., Obida, M., Kogut, K., Bornman, R., Chevrier, J., & Eskenazi, B. (2022). In-utero exposure to DDT and pyrethroids and child behavioral and emotional problems at 2 years of age in the VHEMBE cohort, South Africa. Chemosphere , 306 , 135569. https://doi.org/10.1016/j.chemosphere.2022.135569 Armitage, J. M., Collishaw, S., & Sellers, R. (2024). Explaining long-term trends in adolescent emotional problems: What we know from population-based studies. Discover Social Science and Health , 4 (1), 14. https://doi.org/10.1007/s44155-024-00076-2 *Ashford, J., Smit, F., Van Lier, P. A., Cuijpers, P., & Koot, H. M. (2008). Early risk indicators of internalizing problems in late childhood: A 9-year longitudinal study. Journal of Child Psychology and Psychiatry , 49 (7), 774–780. *Athanasiou, K., Melegkovits, E., Andrie, E. K., Magoulas, C., Tzavara, C. K., Richardson, C., Greydanus, D., Tsolia, M., & Tsitsika, A. K. (2018). Cross-national aspects of cyberbullying victimization among 14–17-year-old adolescents across seven European countries. BMC Public Health , 18 (1), 800. https://doi.org/10.1186/s12889-018-5682-4 Atta, M. H. R., El-Gueneidy, M. M., & Lachine, O. A. R. (2024). The influence of an emotion regulation intervention on challenges in emotion regulation and cognitive strategies in patients with depression. BMC Psychology , 12 (1), 496. https://doi.org/10.1186/s40359-024-01949-6 *Barkmann, C., & Schulte-Markwort, M. (2005). Emotional and behavioral problems of children and adolescents in Germany: An epidemiological screening. Social Psychiatry and Psychiatric Epidemiology , 40 , 357–366. *Bartels, M., Hendriks, A., Mauri, M., Krapohl, E., Whipp, A., Bolhuis, K., Conde, L. C., Luningham, J., Fung Ip, H., Hagenbeek, F., Roetman, P., Gatej, R., Lamers, A., Nivard, M., van Dongen, J., Lu, Y., Middeldorp, C., van Beijsterveldt, T., Vermeiren, R., … Boomsma, D. I. (2018). Childhood aggression and the co-occurrence of behavioural and emotional problems: Results across ages 3–16 years from multiple raters in six cohorts in the EU-ACTION project. European Child and Adolescent Psychiatry , 27 (9), Article 9. https://doi.org/10.1007/s00787-018-1169-1 *Barzeva, S. A., Meeus, W. H. J., & Oldehinkel, A. J. (2019). Social Withdrawal in Adolescence and Early Adulthood: Measurement Issues, Normative Development, and Distinct Trajectories. Journal of Abnormal Child Psychology , 47 (5), 865–879. https://doi.org/10.1007/s10802-018-0497-4 *Bayer, J. K., Hiscock, H., Ukoumunne, O. C., Price, A., & Wake, M. (2008). Early childhood aetiology of mental health problems: A longitudinal population-based study. Journal of Child Psychology and Psychiatry and Allied Disciplines , 49 (11), Article 11. https://doi.org/10.1111/j.1469-7610.2008.01943.x *Bayer, J. K., Ukoumunne, O. C., Mathers, M., Wake, M., Abdi, N., & Hiscock, H. (2012). Development of children’s internalising and externalising problems from infancy to five years of age. Australian & New Zealand Journal of Psychiatry , 46 (7), 659–668. *Bedregal, P., Lermanda, V., Sierra, R., & Viviani, P. (2023). Risk factors associated with higher scores in internalizing and externalizing behaviors in Chilean preschoolers. Infant Mental Health Journal , 44 (5), 663–678. https://doi.org/10.1002/imhj.22082 *Begovac, I., Rudan, V., Skočić, M., Filipović, O., & Szirovicza, L. (2004). Comparison of self-reported and parent-reported emotional and behavioral problems in adolescents from Croatia. Collegium Antropologicum , 28 (1), 393–401. Belsky, J., & Pluess, M. (2009). Beyond diathesis stress: differential susceptibility to environmental influences. Psychological Bulletin , 135 (6), 885-908. *Berg-Nielsen, T. S., Solheim, E., Belsky, J., & Wichstrom, L. (2012). Preschoolers’ Psychosocial Problems: In the Eyes of the Beholder? Adding Teacher Characteristics as Determinants of Discrepant Parent–Teacher Reports. Child Psychiatry & Human Development , 43 (3), 393–413. https://doi.org/10.1007/s10578-011-0271-0 *Berkien, M., Louwerse, A., Verhulst, F., & van der Ende, J. (2012). Children’s perceptions of dissimilarity in parenting styles are associated with internalizing and externalizing behavior. European Child & Adolescent Psychiatry , 21 (2), 79–85. https://doi.org/10.1007/s00787-011-0234-9 *Bhola, P., Manjula, M., Rajappa, V., & Phillip, M. (2017). Predictors of non-suicidal and suicidal self-injurious behaviours, among adolescents and young adults in urban India. Asian Journal of Psychiatry , 29 , 123–128. *Bilenberg, N. (1999). The Child Behavior Checklist (CBCL) and related material: Standardization and validation in Danish population based and clinically based samples. Acta Psychiatrica Scandinavica , 100 , 2–52. *Bishop, S. A., Okagbue, H. I., & Odukoya, J. A. (2020). Statistical analysis of childhood and early adolescent externalizing behaviors in a middle low income country. Heliyon , 6 (2). https://www.cell.com/heliyon/pdf/S2405-8440(20)30222-X.pdf *Bohlin, G., & Janols, L.-O. (2004). Behavioural problems and psychiatric symptoms in 5–13 year-old Swedish children—A comparison of parent ratings on the FTF (Five to Fifteen) with the ratings on CBCL (Child Behavior Checklist). European Child & Adolescent Psychiatry , 13 , iii14–iii22. *Bongers, I. L., Koot, H. M., Van der Ende, J., & Verhulst, F. C. (2003). The normative development of child and adolescent problem behavior. Journal of Abnormal Psychology , 112 (2), 179. Bor, W., Dean, A. J., Najman, J., & Hayatbakhsh, R. (2014). Are child and adolescent mental health problems increasing in the 21st century? A systematic review. Australian & New Zealand Journal of Psychiatry , 48 (7), 606–616. Borg, M. E., Heffer, T., & Willoughby, T. (2024). Generational Shifts in Adolescent Mental Health: A Longitudinal Time-Lag Study. Journal of Youth and Adolescence , 1-12. *Bouvette-Turcot, A.-A., Unternaehrer, E., Gaudreau, H., Lydon, J. E., Steiner, M., Meaney, M. J., & Team, M. R. (2017). The joint contribution of maternal history of early adversity and adulthood depression to socioeconomic status and potential relevance for offspring development. Journal of Affective Disorders , 207 , 26–31. *Boyd, M., Kisely, S., Najman, J., & Mills, R. (2019). Child maltreatment and attentional problems: A longitudinal birth cohort study. Child Abuse & Neglect , 98 , 104170. *Broberg, A. G., Ekeroth, K., Gustafsson, P., Hansson, K., Hägglöf, B., Ivarsson, T., & Larsson, B. (2001). Self-reported competencies and problems among Swedish adolescents: A normative study of the YSR. European Child & Adolescent Psychiatry , 10 , 186–193. *Brunner, R., Parzer, P., Haffner, J., Steen, R., Roos, J., Klett, M., & Resch, F. (2007). Prevalence and psychological correlates of occasional and repetitive deliberate self-harm in adolescents. Archives of Pediatrics & Adolescent Medicine , 161 (7), 641–649. Buecker, S., Mund, M., Chwastek, S., Sostmann, M., & Luhmann, M. (2021). Is loneliness in emerging adults increasing over time? A preregistered cross-temporal meta-analysis and systematic review. Psychological Bulletin , 147 (8), 787. Call, D., Miron, L., & Orcutt, H. (2014). Effectiveness of Brief Mindfulness Techniques in Reducing Symptoms of Anxiety and Stress. Mindfulness , 5 (6), 658–668. https://doi.org/10.1007/s12671-013-0218-6 *Camfferman, R., Jansen, P. W., Rippe, R. C., Mesman, J., Derks, I. P., Tiemeier, H., Jaddoe, V., & Van der Veek, S. M. (2016). The association between overweight and internalizing and externalizing behavior in early childhood. Social Science & Medicine , 168 , 35–42. *Cassidy, A. R. (2016). Executive function and psychosocial adjustment in healthy children and adolescents: A latent variable modelling investigation. Child Neuropsychology , 22 (3), Article 3. https://doi.org/10.1080/09297049.2014.994484 *Cederblad, M., Pruksachatkunakorn, P., Boripunkul, T., Intraprasert, S., & H÷÷k, B÷. (2001). Behaviour Problems and Competence in Thai Children and Youths: Teachers’, Parents’ and Subjects’ Perspectives. Transcultural Psychiatry , 38 (1), 64–79. https://doi.org/10.1177/136346150103800106 *Cerniglia, L., & Cimino, S. (2023). Eating Disorders and Internalizing/Externalizing Symptoms in Adolescents before and during the COVID-19 Pandemic. Journal of the American Nutrition Association , 42 (5), 445–451. https://doi.org/10.1080/07315724.2022.2063206 *Cerniglia, L., Cimino, S., & Ammaniti, M. (2021). What are the effects of screen time on emotion regulation and academic achievements? A three-wave longitudinal study on children from 4 to 8 years of age. Journal of Early Childhood Research , 19 (2), 145–160. *Chang, J.-C., Huang, W.-L., Chen, Y.-L., & Gau, S. S.-F. (2020). The mental health of immigrant mother’s offspring in Taiwan: A national epidemiological study. Journal of the Formosan Medical Association = Taiwan Yi Zhi , 119 (2), 601–609. https://doi.org/10.1016/j.jfma.2019.08.033 Chen, C.-Y., Storr, C. L., Tang, G.-M., Huang, S.-L., Hsiao, C. K., & Chen, W. J. (2008). Early alcohol experiences and adolescent mental health: A population-based study in Taiwan. Drug and Alcohol Dependence , 95 (3), 209–218. https://doi.org/10.1016/j.drugalcdep.2008.01.018 *Chen, Y.-Y., Ho, S.-Y., Lee, P.-C., Wu, C.-K., & Gau, S. S.-F. (2017). Parent-child discrepancies in the report of adolescent emotional and behavioral problems in Taiwan. PLoS One , 12 (6), e0178863. *Choe, R., Sim, Y. F., Hong, C. H. L., Mohideen, S., Nadarajan, R., Yap, F., Shek, L. P.-C., Hsu, C.-Y. S., Broekman, B. F. P., & Ferreira, J. N. (2021). Internalizing problems are associated with oral health-related quality of life in early childhood: Outcomes from an Asian multi-ethnic prospective birth cohort. PloS One , 16 (8), e0256163. https://doi.org/10.1371/journal.pone.0256163 *Christensen, H. B., & Bilenberg, N. (2000). Behavioural and emotional problems in children of alcoholic mothers and fathers. European Child & Adolescent Psychiatry , 9 (3), 219–226. Collishaw, S. (2015). Annual research review: Secular trends in child and adolescent mental health. Journal of Child Psychology and Psychiatry , 56 (3), 370–393. Collishaw, S., Maughan, B., Goodman, R., & Pickles, A. (2004). Time trends in adolescent mental health. Journal of Child Psychology and Psychiatry , 45 (8), 1350–1362. Collishaw, S., Maughan, B., Natarajan, L., & Pickles, A. (2010). Trends in adolescent emotional problems in England: A comparison of two national cohorts twenty years apart. Journal of Child Psychology and Psychiatry , 51 (8), 885–894. https://doi.org/10.1111/j.1469-7610.2010.02252.x Coory, M. D. (2010). Comment on: Heterogeneity in meta-analysis should be expected and appropriately quantified. International Journal of Epidemiology , 39 (3), 932–932. Cosma, A., Stevens, G., Martin, G., Duinhof, E. L., Walsh, S. D., Garcia-Moya, I., ... & De Looze, M. (2020). Cross-national time trends in adolescent mental well-being from 2002 to 2018 and the explanatory role of schoolwork pressure. Journal of Adolescent Health , 66 (6), S50-S58. *Coulombe, J. A., Reid, G. J., Boyle, M. H., & Racine, Y. (2010). Sleep problems, tiredness, and psychological symptoms among healthy adolescents. Journal of Pediatric Psychology , 36 (1), 25–35. Cox, D. D. (2005). Evidence-based interventions using home-school collaboration. School Psychology Quarterly , 20 (4), 473. Crijnen, A. A., Achenbach, T. M., & Verhulst, F. C. (1999). Problems reported by parents of children in multiple cultures: The Child Behavior Checklist syndrome constructs. American Journal of Psychiatry , 156 (4), 569–574. *Cui, Y., Li, F., Leckman, J. F., Guo, L., Ke, X., Liu, J., Zheng, Y., & Li, Y. (2021). The prevalence of behavioral and emotional problems among Chinese school children and adolescents aged 6–16: A national survey. European Child & Adolescent Psychiatry , 30 , 233–241. *Darvay, S, Gádoros, J., Joubert, K., Ágfalvi Varga Teghze-Gerber, R. & Rózsa, Zs., S. (1996). Effect of maturity at birth on the child behavior. Anthropologiai. Közlemény. , 38 , 165–170. Davoodi, E., Sharifi, T., & Ahmadi, R. (2024). Comparison of the Effectiveness of Group Training of Positive Thinking Skills and Stress Management Based on Cognitive-Behavioral Approach on Perceived Stress and Rumination of Female Students of the First Year of High School Students with Test Anxiety. Journal of Applied Psychological Research . https://japr.ut.ac.ir/article_98595_en.html De Los Reyes, A., Thomas, S. A., Goodman, K. L., & Kundey, S. M. A. (2013). Principles Underlying the Use of Multiple Informants’ Reports. Annual Review of Clinical Psychology , 9 (1), 123–149. https://doi.org/10.1146/annurev-clinpsy-050212-185617 *Dekker, M. C., Koot, H. M., van der Ende, J., & Verhulst, F. C. (2002). Emotional and behavioral problems in children and adolescents with and without intellectual disability. Journal of Child Psychology and Psychiatry, and Allied Disciplines , 43 (8), 1087–1098. https://doi.org/10.1111/1469-7610.00235 *Desmarais, E., Brown, K., Campbell, K., French, B. F., Putnam, S. P., Casalin, S., Linhares, M. B. M., Lecannelier, F., Wang, Z., & Raikkonen, K. (2021). Links between television exposure and toddler dysregulation: Does culture matter? Infant Behavior and Development , 63 , 101557. Dotti Sani, G. M., & Treas, J. (2016). Educational gradients in parents’ child‐care time across countries, 1965–2012. Journal of Marriage and Family , 78 (4), 1083–1096. Dudani, A., Macpherson, A., & Tamim, H. (2010). Childhood behavior problems and unintentional injury: A longitudinal, population-based study. Journal of Developmental & Behavioral Pediatrics , 31 (4), 276–285. Durrant, J., & Ensom, R. (2012). Physical punishment of children: Lessons from 20 years of research. CMAJ , 184 (12), 1373–1377. *Effenberger, P. S., Send, T. S., Gilles, M., Wolf, I. A. C., Frank, J., Bongard, S., Kumsta, R., Witt, S. H., Rietschel, M., Deuschle, M., & Streit, F. (2022). Urbanicity, behavior problems and HPA axis regulation in preschoolers. Psychoneuroendocrinology , 137 , 105660. https://doi.org/10.1016/j.psyneuen.2022.105660 El Marroun, H., White, T. J., van der Knaap, N. J., Homberg, J. R., Fernandez, G., Schoemaker, N. K., Jaddoe, V. W., Hofman, A., Verhulst, F. C., & Hudziak, J. J. (2014). Prenatal exposure to selective serotonin reuptake inhibitors and social responsiveness symptoms of autism: Population-based study of young children. The British Journal of Psychiatry , 205 (2), 95–102. Ellersgaard, D., Jessica Plessen, K., Richardt Jepsen, J., Soeborg Spang, K., Hemager, N., Klee Burton, B., Jerlang Christiani, C., Gregersen, M., Søndergaard, A., & Uddin, M. J. (2018). Psychopathology in 7‐year‐old children with familial high risk of developing schizophrenia spectrum psychosis or bipolar disorder–The Danish High Risk and Resilience Study‐VIA 7, a population‐based cohort study. World Psychiatry , 17 (2), 210–219. *Equit, M., Klein, A.-M., Braun-Bither, K., Gräber, S., & von Gontard, A. (2014). Elimination disorders and anxious-depressed symptoms in preschool children: A population-based study. European Child & Adolescent Psychiatry , 23 , 417–423. *Erol, N., Simsek, Z., Oner, O., & Munir, K. (2005). Behavioral and emotional problems among Turkish children at ages 2 to 3 years. Journal of the American Academy of Child & Adolescent Psychiatry , 44 (1), 80–87. *Erol, N., Simsek, Z., Oner, O., & Munir, K. (2008). Epidemiology of Attention Problems Among Turkish Children and Adolescents A National Study. JOURNAL OF ATTENTION DISORDERS , 11 (5), Article 5. https://doi.org/10.1177/1087054707311214 *Evans, S. F., Kobrosly, R. W., Barrett, E. S., Thurston, S. W., Calafat, A. M., Weiss, B., Stahlhut, R., Yolton, K., & Swan, S. H. (2014). Prenatal bisphenol A exposure and maternally reported behavior in boys and girls. Neurotoxicology , 45 , 91–99. https://doi.org/10.1016/j.neuro.2014.10.003 Evans-Lacko, S., Corker, E., Williams, P., Henderson, C., & Thornicroft, G. (2014). Effect of the Time to Change anti-stigma campaign on trends in mental-illness-related public stigma among the English population in 2003–13: An analysis of survey data. The Lancet Psychiatry , 1 (2), 121–128. Evans-Lacko, S., Takizawa, R., Brimblecombe, N., King, D., Knapp, M., Maughan, B., & Arseneault, L. (2017). Childhood bullying victimization is associated with use of mental health services over five decades: A longitudinal nationally representative cohort study. Psychological Medicine , 47 (1), 127–135. *Faleschini, S., Doyon, M., Arguin, M., Lepage, J.-F., Tiemeier, H., Van Lieshout, R. J., Perron, P., Bouchard, L., & Hivert, M.-F. (2023). Maternal Hyperglycemia in Pregnancy and Offspring Internalizing and Externalizing Behaviors. Maternal and Child Health Journal , 27 (10), 1765–1773. *Fang, Y., Raat, H., Windhorst, D. A., Fierloos, I. N., Jonkman, H., Hosman, C. M., Crone, M. R., Jansen, W., & van Grieken, A. (2022). The association between stressful life events and emotional and behavioral problems in children 0–7 years old: The CIKEO study. International Journal of Environmental Research and Public Health , 19 (3), 1650. *Fanti, K. A., & Henrich, C. C. (2010). Trajectories of pure and co-occurring internalizing and externalizing problems from age 2 to age 12: Findings from the National Institute of Child Health and Human Development Study of Early Child Care. Developmental Psychology , 46 (5), 1159–1175. https://doi.org/10.1037/a0020659 Farrington, D. P., & Welsh, B. C. (2008). Saving Children from a Life of Crime: Early Risk Factors and Effective Interventions . Oxford University Press. Fernandez-Berrocal, P., Alcaide, R., Extremera, N., & Pizarro, D. (2006). The role of emotional intelligence in anxiety and depression among adolescents. Individual Differences Research , 4 (1). https://www.academia.edu/download/30661585/PDF60among_adolescents.pdf Fine, S. L., Musci, R. J., Bass, J. K., Chipeta, E., Mafuta, E. M., Pinandari, A. W., ... & Blum, R. W. (2022). A multi-country study of risk and protective factors for emotional and behavioral problems among early adolescents. Journal of Adolescent Health , 71 (4), 480-487. *Fitzpatrick, C., & Deehan, A. (1999). Competencies and problems of Irish children and adolescents. European Child & Adolescent Psychiatry , 8 (1), 17–23. *Fombonne, E. (1992). Parent reports on behaviour and competencies among 6–11-year-old French Children. European Child & Adolescent Psychiatry , 1 (4), 233–243. https://doi.org/10.1007/BF02094184 Fombonne, E. (1998). Increased rates of psychosocial disorders in youth. European Archives of Psychiatry and Clinical Neuroscience , 248 , 14-21. Ford, T. (2008). Practitioner review: How can epidemiology help us plan and deliver effective child and adolescent mental health services?. Journal of Child Psychology and Psychiatry , 49 (9), 900-914. Ford, T., & Parker, C. (2016). Emotional and behavioural difficulties and mental (ill)health. Emotional and Behavioural Difficulties , 21 (1), 1–7. https://doi.org/10.1080/13632752.2016.1139300 Foulkes, L., & Andrews, J. L. (2023). Are mental health awareness efforts contributing to the rise in reported mental health problems? A call to test the prevalence inflation hypothesis. New Ideas in Psychology , 69 , 101010. *Francis, K., Katsani, G., Sotiropoulou, X., Roussos, A., & Roussos, C. (2007). Cigarette Smoking Among Greek Adolescents: Behavior, Attitudes, Risk, and Preventive Factors. Substance Use & Misuse , 42 (8), 1323–1336. https://doi.org/10.1080/10826080701212410 *Fransson, E., Sörensen, F., Kallak, T. K., Ramklint, M., Eckerdal, P., Heimgärtner, M., Krägeloh-Mann, I., & Skalkidou, A. (2020). Maternal perinatal depressive symptoms trajectories and impact on toddler behavior–the importance of symptom duration and maternal bonding. Journal of Affective Disorders , 273 , 542–551. *Frigerio, A., Cattaneo, C., Cataldo, M., Schiatti, A., Molteni, M., & Battaglia, M. (2004). Behavioral and emotional problems among Italian children and adolescents aged 4 to 18 years as reported by parents and teachers. European Journal of Psychological Assessment , 20 (2), 124–133. Garcia, O. F., Fuentes, M. C., Gracia, E., Serra, E., & Garcia, F. (2020). Parenting warmth and strictness across three generations: Parenting styles and psychosocial adjustment. International Journal of Environmental Research and Public Health , 17 (20), 7487. *Garton, A. F., Zubrick, S. R., & Silburn, S. R. (1995). The Western Australian child health survey: A pilot study. The Australian and New Zealand Journal of Psychiatry , 29 (1), 48–57. https://doi.org/10.3109/00048679509075891 *Ghassabian, A., Bongers-Schokking, J. J., Henrichs, J., Jaddoe, V. W., Visser, T. J., Visser, W., de Muinck Keizer-Schrama, S. M., Hooijkaas, H., Steegers, E. A., & Hofman, A. (2011). Maternal thyroid function during pregnancy and behavioral problems in the offspring: The generation R study. Pediatric Research , 69 (7), 454–459. *Giles, L., Davies, M., Whitrow, M., Rumbold, A., Lynch, J., Sawyer, M., & Moore, V. (2011). Structured regression analyses of life course processes: An example exploring how maternal depression in early childhood affects children’s subsequent internalizing behavior. Annals of Epidemiology , 21 (9), 654–659. *Girard, L.-C., & Farkas, C. (2019). Breastfeeding and behavioural problems: Propensity score matching with a national cohort of infants in Chile. BMJ Open , 9 (2), Article 2. https://doi.org/10.1136/bmjopen-2018-025058 *Glover, S. H., Pumariega, A. J., Holzer, C. E., Wise, B. K., & Rodriguez, M. (1999). Anxiety symptomatology in Mexican-American adolescents. Journal of Child and Family Studies , 8 , 47–57. Gonthier, C., & Grégoire, J. (2022). Flynn effects are biased by differential item functioning over time: A test using overlapping items in Wechsler scales. Intelligence , 95 , 101688. Goodman, R. (1997). The Strengths and Difficulties Questionnaire: A Research Note. Journal of Child Psychology and Psychiatry , 38 (5), 581–586. https://doi.org/10.1111/j.1469-7610.1997.tb01545.x *Gori, A., Giannini, M., Topino, E., Cacioppo, M., Palmieri, G., De Sanctis, E., Loscalzo, Y., Burgassi, C., Manzi, C., & Giovannelli, P. (2021). Mental health and rural communities: Prevalence of psychopathology among children and preadolescents in a mountainous area of Italy. J. Psychopathol , 27 , 90–98. Graves, L. V., Drozdick, L., Courville, T., Farrer, T. J., Gilbert, P. E., & Delis, D. C. (2021). Cohort differences on the CVLT-II and CVLT3: Evidence of a negative Flynn effect on the attention/working memory and learning trials. The Clinical Neuropsychologist , 35 (3), 615–632. Griffin, E., McMahon, E., McNicholas, F., Corcoran, P., Perry, I. J., & Arensman, E. (2018). Increasing rates of self-harm among children, adolescents and young adults: A 10-year national registry study 2007–2016. Social Psychiatry and Psychiatric Epidemiology , 53 , 663–671. *Grigorenko, E. L., Geiser, C., Slobodskaya, H. R., & Francis, D. J. (2010). Cross-informant symptoms from CBCL, TRF, and YSR: Trait and method variance in a normative sample of Russian youths. Psychological Assessment , 22 (4), 893. Grossmann, I., Varnum, M. E., Hutcherson, C. A., & Mandel, D. R. (2024). When expert predictions fail. Trends in Cognitive Sciences , 28 (2), 113-123. *Guerrero, M. D., Barnes, J. D., Chaput, J.-P., & Tremblay, M. S. (2019). Screen time and problem behaviors in children: Exploring the mediating role of sleep duration. International Journal of Behavioral Nutrition and Physical Activity , 16 (1), 1–10. *Guerrero, N., Gangnon, R., Curtis, M. A., Valdez, C. R., Ehrenthal, D. B., & Jacobs, E. A. (2021). The association between exposure to maternal depression during year 2 of a child’s life and future child problem behavior. Maternal and Child Health Journal , 25 , 731–740. *Guilbert, A., Rolland, M., Pin, I., Thomsen, C., Sakhi, A. K., Sabaredzovic, A., Slama, R., Guichardet, K., & Philippat, C. (2021). Associations between a mixture of phenols and phthalates and child behaviour in a French mother-child cohort with repeated assessment of exposure. Environment International , 156 , 106697. https://doi.org/10.1016/j.envint.2021.106697 Gutman, L. M., & Codiroli McMaster, N. (2020). Gendered Pathways of Internalizing Problems from Early Childhood to Adolescence and Associated Adolescent Outcomes. Journal of Abnormal Child Psychology , 48 (5), 703–718. https://doi.org/10.1007/s10802-020-00623-w Haller, H., Cramer, H., Lauche, R., Gass, F., & Dobos, G. J. (2014). The prevalence and burden of subthreshold generalized anxiety disorder: A systematic review. BMC Psychiatry , 14 (1), 128. https://doi.org/10.1186/1471-244X-14-128 *Hannesdóttir, H., & Einarsdóttir, S. (1995). The Icelandic Child Mental Health Study. An epidemiological study of Icelandic children 2–18 years of age using the Child Behavior Checklist as a screening instrument. European Child & Adolescent Psychiatry , 4 (4), 237–248. *Hay, D. F., van Goozen, S. H., Mundy, L., Phillips, R., Roberts, S., Meeuwsen, M., Goodyer, I., & Perra, O. (2017). If you go down to the woods today: Infants’ distress during a teddy bear’s picnic in relation to peer relations and later emotional problems. Infancy , 22 (4), 552–570. *Heflinger, C. A., Simpkins, C. G., & Combs-Orme, T. (2000). Using the CBCL to determine the clinical status of children in state custody. Children and Youth Services Review , 22 (1), 55–73. *Hellinckx, W., Grietens, H., & De Munter, A. (2000). 12 Parent-reported Problem Behavior in12-16-Year Old American and Russian Children: A Cross-National Comparison. In International perspectives on child and adolescent mental health (Vol. 1, pp. 205–222). Elsevier. *Hellinckx, W., Grietens, H., & Verhulst, F. (1994). Competence and behavioral problems in 6-to 12-year-old children in Flanders (Belgium) and Holland: A cross-national comparison. Journal of Emotional and Behavioral Disorders , 2 (3), 130–142. *Henriksen, J., Nielsen, P. F., & Bilenberg, N. (2012). New Danish standardization of the Child Behaviour Checklist. Danish Medical Journal , 59 (7), A4462. *Hensley, V. R. (1988). Australian normative study of the Achenbach child behaviour checklist. Australian Psychologist , 23 (3), 371–382. *Heyerdahl, S., Kvernmo, S., & Wichstrøm, L. (2004). Self-reported behavioural/emotional problems in Norwegian adolescents from multiethnic areas. European Child & Adolescent Psychiatry , 13 , 64–72. Hilt, L. M., & Pollak, S. D. (2012). Getting Out of Rumination: Comparison of Three Brief Interventions in a Sample of Youth. Journal of Abnormal Child Psychology , 40 (7), 1157–1165. https://doi.org/10.1007/s10802-012-9638-3 *Hoffmann, M. D., Barnes, J. D., Tremblay, M. S., & Guerrero, M. D. (2022). Associations between organized sport participation and mental health difficulties: Data from over 11,000 US children and adolescents. PLoS One , 17 (6), e0268583. Högberg, B., Strandh, M., Johansson, K., & Petersen, S. (2023). Trends in adolescent psychosomatic complaints: A quantile regression analysis of Swedish HBSC data 1985–2017. Scandinavian Journal of Public Health , 51 (4), 619–627. https://doi.org/10.1177/14034948221094497 Holland, M. L., Malmberg, J., & Peacock, G. G. (2017). Emotional and behavioral problems of young children: Effective interventions in the preschool and kindergarten years . Guilford Publications. Hölling, H., Schlack, R., Petermann, F., Ravens-Sieberer, U., & Mauz, E. (2014). Psychische Auffälligkeiten und psychosoziale Beeinträchtigungen bei Kindern und Jugendlichen im Alter von 3 bis 17 Jahren in Deutschland–Prävalenz und zeitliche Trends zu 2 Erhebungszeitpunkten (2003–2006 und 2009–2012) . https://edoc.rki.de/handle/176904/1894 Huang, C. (2017). Cross-informant agreement on the child behavior checklist for youths: A meta-analysis. Psychological Reports , 120 (6), 1096–1116. Inchley, J. C., Willis, M., Mabelis, J., Brown, J., & Currie, D. B. (2023). Inequalities in health complaints: 20-year trends among adolescents in Scotland, 1998–2018. Frontiers in Psychology , 14 , 1095117. Ishizuka, P. (2019). Social class, gender, and contemporary parenting standards in the United States: Evidence from a national survey experiment. Social Forces , 98 (1), 31–58. Ivanova, M. Y., Achenbach, T. M., Rescorla, L. A., Dumenci, L., Almqvist, F., Bilenberg, N., Bird, H., Broberg, A. G., Dobrean, A., Döpfner, M., Erol, N., Forns, M., Hannesdottir, H., Kanbayashi, Y., Lambert, M. C., Leung, P., Minaei, A., Mulatu, M. S., Novik, T., … Verhulst, F. C. (2007). The generalizability of the Youth Self-Report syndrome structure in 23 societies. Journal of Consulting and Clinical Psychology , 75 (5), 729–738. https://doi.org/10.1037/0022-006X.75.5.729 Ivanova, M. Y., Achenbach, T. M., Rescorla, L. A., Guo, J., Althoff, R. R., Kan, K.-J., Almqvist, F., Begovac, I., Broberg, A. G., Chahed, M., Da Rocha, M. M., Dobrean, A., Döepfner, M., Erol, N., Fombonne, E., Fonseca, A. C., Forns, M., Frigerio, A., Grietens, H., … Verhulst, F. C. (2019). Testing Syndromes of Psychopathology in Parent and Youth Ratings Across Societies. Journal of Clinical Child & Adolescent Psychology , 48 (4), 596–609. https://doi.org/10.1080/15374416.2017.1405352 Ivanova, M. Y., Dobrean, A., Dopfner, M., Erol, N., Fombonne, E., Fonseca, A. C., Frigerio, A., Grietens, H., Hannesdottir, H., Kanbayashi, Y., Lambert, M., Achenbach, T. M., Larsson, B., Leung, P., Liu, X., Minaei, A., Mulatu, M. S., Novik, T. S., Oh, K. J., … Chen, W. J. (2007). Testing the 8-syndrome structure of the child behavior checklist in 30 societies. Journal of Clinical Child and Adolescent Psychology : The Official Journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53 , 36 (3), Article 3. https://doi.org/10.1080/15374410701444363 *Jansen, J., Van Schaik, G., Renes, R., & Lam, T. (2010). The effect of a national mastitis control program on the attitudes, knowledge, and behavior of farmers in the Netherlands. Journal of Dairy Science , 93 (12), 5737–5747. Johnson, J. C. S., Byrne, G. J., & Pelecanos, A. M. (2022). The prevalence of subthreshold psychiatric symptoms and associations with alcohol and substance use disorders: From a nationally representative survey of 36,309 adults. BMC Psychiatry , 22 (1), 270. https://doi.org/10.1186/s12888-022-03834-1 Jones, C. J., & Meredith, W. (2000). Developmental paths of psychological health from early adolescence to later adulthood. Psychology and Aging , 15 (2), 351. *Jozefiak, T., Larsson, B., Wichstrøm, L., & Rimehaug, T. (2012). Competence and emotional/behavioural problems in 7-16-year-old Norwegian school children as reported by parents. Nordic Journal of Psychiatry , 66 (5), 311–319. https://doi.org/10.3109/08039488.2011.638934 *Kaess, M., Parzer, P., Haffner, J., Steen, R., Roos, J., Klett, M., Brunner, R., & Resch, F. (2011). Explaining gender differences in non-fatal suicidal behaviour among adolescents: A population-based study. BMC Public Health , 11 , 1–7. *Kahr Nilsson, K., Landorph, S., Houmann, T., Olsen, E. M., & Skovgaard, A. M. (2019). Developmental and mental health characteristics of children exposed to psychosocial adversity and stressors at the age of 18-months: Findings from a population-based cohort study. Infant Behavior & Development , 57 , 101319. https://doi.org/10.1016/j.infbeh.2019.04.001 *Kapi, A., Veltsista, A., Sovio, U., Järvelin, M.-R., & Bakoula, C. (2007). Comparison of self-reported emotional and behavioural problems in adolescents from Greece and Finland. Acta Paediatrica (Oslo, Norway : 1992) , 96 (8), 1174–1179. https://doi.org/10.1111/j.1651-2227.2007.00370.x *Kariuki, S. M., Abubakar, A., Kombe, M., Kazungu, M., Odhiambo, R., Stein, A., & Newton, C. R. (2018). Prevalence, risk factors and behavioural and emotional comorbidity of acute seizures in young Kenyan children: A population-based study. BMC Medicine , 16 (1), 1–12. *Kekkonen, V. K., Kivimäki, P., Valtonen, H., Tolmunen, T., Lehto, S. M., Hintikka, J., & Laukkanen, E. (2015). Psychosocial problems in adolescents associated with frequent health care use. Family Practice , 32 (3), 305–310. https://doi.org/10.1093/fampra/cmu090 Kennedy, R. S. (2021). Bullying Trends in the United States: A Meta-Regression. Trauma, Violence, & Abuse , 22 (4), 914–927. https://doi.org/10.1177/1524838019888555 *Kerr, D. C., Lunkenheimer, E. S., & Olson, S. L. (2007). Assessment of child problem behaviors by multiple informants: A longitudinal study from preschool to school entry. Journal of Child Psychology and Psychiatry , 48 (10), 967–975. Khan, M., Minbashian, A., & MacCann, C. (2021). College students in the western world are becoming less emotionally intelligent: A cross‐temporal meta‐analysis of trait emotional intelligence. Journal of Personality , 89 (6), 1176–1190. Kim, H., Choi, J., & Oh, Y. (2021). The impact of maternal personality traits on behavioral problems in preschool-aged children: A population-based panel study in South Korea. Archives of Women’s Mental Health , 24 (2), 321–328. *Klahr, A. M., Klump, K. L., & Burt, S. A. (2014). The etiology of the association between child antisocial behavior and maternal negativity varies across aggressive and non-aggressive rule-breaking forms of antisocial behavior. Journal of Abnormal Child Psychology , 42 , 1299–1311. *Klassen, A. F., Lee, S. K., Raina, P., Chan, H. W. P., Matthew, D., & Brabyn, D. (2004). Health status and health-related quality of life in a population-based sample of neonatal intensive care unit graduates. Pediatrics , 113 (3 Pt 1), 594–600. https://doi.org/10.1542/peds.113.3.594 *Knudsen, A. K., Ystrom, E., Skogen, J. C., & Torgersen, L. (2015). Maternal heavy alcohol use and toddler behavior problems: A fixed effects regression analysis. European Child & Adolescent Psychiatry , 24 , 1269–1277. *Kobrosly, R. W., Evans, S., Miodovnik, A., Barrett, E. S., Thurston, S. W., Calafat, A. M., & Swan, S. H. (2014). Prenatal phthalate exposures and neurobehavioral development scores in boys and girls at 6–10 years of age. Environmental Health Perspectives , 122 (5), 521–528. *Koenig, J., Oelkers-Ax, R., Parzer, P., Haffner, J., Brunner, R., Resch, F., & Kaess, M. (2015). The association of self-injurious behaviour and suicide attempts with recurrent idiopathic pain in adolescents: Evidence from a population-based study. Child and Adolescent Psychiatry and Mental Health , 9 , 1–9. Kotov, R., Krueger, R. F., Watson, D., Achenbach, T. M., Althoff, R. R., Bagby, R. M., ... & Zimmerman, M. (2017). The Hierarchical Taxonomy of Psychopathology (HiTOP): A dimensional alternative to traditional nosologies. Journal of Abnormal Psychology , 126 (4), 454. *Kristensen, S., Henriksen, T. B., & Bilenberg, N. (2010). The Child Behavior Checklist for Ages 1.5–5 (CBCL/1½–5): Assessment and analysis of parent-and caregiver-reported problems in a population-based sample of Danish preschool children. Nordic Journal of Psychiatry , 64 (3), 203–209. *Lambert, M. C., & Lyubansky, M. (1999). Behavior and emotional problems among Jamaican children and adolescents: An epidemiological survey of parent, teacher, and self-reports for ages 6–18 years. International Journal of Intercultural Relations , 23 (5), 727–751. *Lansford, J. E., Malone, P. S., Dodge, K. A., Crozier, J. C., Pettit, G. S., & Bates, J. E. (2006). A 12-year prospective study of patterns of social information processing problems and externalizing behaviors. Journal of Abnormal Child Psychology , 34 , 709–718. *Larsson, B., & Drugli, M. B. (2011). School competence and emotional/behavioral problems among Norwegian school children as rated by teachers on the Teacher Report Form. Scandinavian Journal of Psychology , 52 (6), 553–559. https://doi.org/10.1111/j.1467-9450.2011.00889.x *Larsson, B., & Frisk, M. (1999). Social competence and emotional/behaviour problems in 6–16 year-old Swedish school children. European Child & Adolescent Psychiatry , 8 (1), 24–33. *Li, Y.-C., Kwan, M. Y., King-Dowling, S., Rodriguez, M. C., & Cairney, J. (2021). Does physical activity and BMI mediate the association between DCD and internalizing problems in early childhood? A partial test of the Environmental Stress Hypothesis. Human Movement Science , 75 , 102744. *Liang, Y., Zhou, Y., Ruzek, J. I., & Liu, Z. (2020). Patterns of childhood trauma and psychopathology among Chinese rural-to-urban migrant children. Child Abuse & Neglect , 108 , 104691. *Lisi, G., Rossi, R., Ribolsi, M., Di Lorenzo, G., Parisi, C., Siracusano, M., Morciano, L., De Stefano, A., Pesaresi, A., Niolu, C., Palombi, L., & Siracusano, A. (2020). ‘Too many BeEPs in our teens!’ Behavioral and emotional problems in a large group of Italian adolescents. Psychological Medicine , 1–10. https://doi.org/10.1017/S0033291720002767 *Liu, J., Cheng, H., & Leung, P. W. (2011). The application of the preschool child behavior checklist and the caregiver–teacher report form to mainland chinese children: Syndrome structure, gender differences, country effects, and inter-informant agreement. Journal of Abnormal Child Psychology , 39 , 251–264. *Liu, X., Kurita, H., Guo, C., Miyake, Y., Ze, J., & Cao, H. (1999). Prevalence and risk factors of behavioral and emotional problems among Chinese children aged 6 through 11 years. Journal of the American Academy of Child & Adolescent Psychiatry , 38 (6), 708–715. *Liu, X., Kurita, H., Guo, C., Tachimori, H., Ze, J., & Okawa, M. (2000). Behavioral and emotional problems in Chinese children: Teacher reports for ages 6 to 11. Journal of Child Psychology and Psychiatry, and Allied Disciplines , 41 (2), 253–260. *Loftus, C. T., Ni, Y., Szpiro, A. A., Hazlehurst, M. F., Tylavsky, F. A., Bush, N. R., Sathyanarayana, S., Carroll, K. N., Young, M., & Karr, C. J. (2020). Exposure to ambient air pollution and early childhood behavior: A longitudinal cohort study. Environmental Research , 183 , 109075. *Loo, S. K., & Rapport, M. D. (1998). Ethnic variations in children’s problem behaviors: A cross-sectional, developmental study of Hawaii school children. The Journal of Child Psychology and Psychiatry and Allied Disciplines , 39 (4), 567–575. *Luan, M., Zhang, X., Fang, G., Liang, H., Yang, F., Song, X., Chen, Y., Yuan, W., & Miao, M. (2022). Preconceptional paternal alcohol consumption and the risk of child behavioral problems: A prospective cohort study. Scientific Reports , 12 (1), 1508. *Machado, B. C., Dias, P., Lima, V. S., Campos, J., & Gonçalves, S. (2016). Prevalence and correlates of picky eating in preschool-aged children: A population-based study. Eating Behaviors , 22 , 16–21. *Machado, B. C., Dias, P., Lima, V. S., Carneiro, A., & Gonçalves, S. (2021). Frequency and correlates of picky eating and overeating in school-aged children: A Portuguese population-based study. Journal of Child and Family Studies , 30 , 1198–1213. Maughan, B., Collishaw, S., Meltzer, H., & Goodman, R. (2008). Recent trends in UK child and adolescent mental health. Social Psychiatry and Psychiatric Epidemiology , 43 , 305–310. McGorry, P. D., Mei, C., Dalal, N., Alvarez-Jimenez, M., Blakemore, S. J., Browne, V., ... & Killackey, E. (2024). The Lancet Psychiatry Commission on youth mental health. The Lancet Psychiatry , 11 (9), 731-774. *McKelvey, R. S., Davies, L. C., Sang, D. L., Pickering, K. R., & Tu, H. C. (1999). Problems and competencies reported by parents of Vietnamese children in Hanoi. Journal of the American Academy of Child & Adolescent Psychiatry , 38 (6), 731–737. *McKnight, C. G., Huebner, E. S., & Suldo, S. (2002). Relationships among stressful life events, temperament, problem behavior, and global life satisfaction in adolescents. Psychology in the Schools , 39 (6), 677–687. *Miller, A. R., Kohen, D., & Johnston, C. (2008). Child characteristics and receipt of stimulant medications: A population-based study. Ambulatory Pediatrics , 8 (3), 175–181. Mossin, M. H., Aaby, J. B., Dalgård, C., Lykkedegn, S., Christesen, H. T., & Bilenberg, N. (2017). Inverse associations between cord vitamin D and attention deficit hyperactivity disorder symptoms: A child cohort study. Australian & New Zealand Journal of Psychiatry , 51 (7), 703–710. *Motti-Stefanidi, F., Tsiantis, J., & Richardson, S. (1993). Epidemiology of behavioural and emotional problems of primary schoolchildren in Greece. European Child & Adolescent Psychiatry , 2 , 111–118. Murray, D. W., Rosanbalm, K. D., Christopoulos, C., & Hamoudi, A. (2015). Self-regulation and toxic stress: Foundations for understanding self-regulation from an applied developmental perspective . Mustonen, A., Alakokkare, A.-E., Salom, C., Hurtig, T., Levola, J., Scott, J. G., Miettunen, J., & Niemelä, S. (2021). Age of first alcohol intoxication and psychiatric disorders in young adulthood—A prospective birth cohort study. Addictive Behaviors , 118 , 106910. https://doi.org/10.1016/j.addbeh.2021.106910 *Nøvik, T. S. (1999). Validity of the Child Behaviour Checklist in a Norwegian sample. European Child & Adolescent Psychiatry , 8 (4), 247–254. *Obando, D., Hill, J., Sharp, H., Pickles, A., Fisher, L., & Wright, N. (2022). Synergy between callous–unemotional traits and aggression in preschool children: Cross-informant and cross-cultural replication in the UK Wirral Child Health and Development Study, and the Colombian La Sabana Parent–Child Study. Development and Psychopathology , 34 (3), 1079–1087. *Obot, I. S., & Anthony, J. C. (2004). Mental Health Problems in Adolescent Children of Alcohol Dependent Parents: Epidemiologic Research with a Nationally Representative Sample. Journal of Child & Adolescent Substance Abuse , 13 (4), 83–96. https://doi.org/10.1300/J029v13n04_06 Oerbeck, B., Overgaard, K. R., Pripp, A. H., Reichborn-Kjennerud, T., Aase, H., & Zeiner, P. (2020). Early predictors of ADHD: evidence from a prospective birth cohort. Journal of Attention Disorders , 24 (12), 1685–1692. *Okada, M., Otaga, M., Tsutsui, T., Tachimori, H., Kitamura, S., Higuchi, S., & Mishima, K. (2018). Association of sleep with emotional and behavioral problems among abused children and adolescents admitted to residential care facilities in Japan. PloS One , 13 (6), e0198123. Olkin, I., & Gleser, L. (2009). Stochastically dependent effect sizes. The Handbook of Research Synthesis and Meta-Analysis , 2 , 357–376. *Öncü, B., Öner, Ö., Öner, P., Erol, N., Aysev, A., & Canat, S. (2004). Symptoms defined by parents’ and teachers’ ratings in attention-deficit hyperactivity disorder: Changes with age. The Canadian Journal of Psychiatry , 49 (7), 487–491. Otterman, D. L., Koopman-Verhoeff, M. E., White, T. J., Tiemeier, H., Bolhuis, K., & Jansen, P. W. (2019). Executive functioning and neurodevelopmental disorders in early childhood: A prospective population-based study. Child and Adolescent Psychiatry and Mental Health , 13 , 1–12. Our World in Data. (2016). World population living in extreme poverty . https://ourworldindata.org/grapher/world-population-in-extreme-poverty-absolute?stackMode=relative Our World in Data. (2018). World population by level of education . https://ourworldindata.org/grapher/projection-of-world-population-SSP2-IIASA Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., Shamseer, L., Tetzlaff, J. M., Akl, E. A., & Brennan, S. E. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. Bmj , 372 . https://www.bmj.com/content/372/bmj.n71.short Panchal, U., Vaquerizo-Serrano, J. D., Conde-Ghigliazza, I., Genc, H. A., Marchini, S., Pociute, K., Ocakoğlu, B. K., Sanchez-Roman, S., Ori, D., & Catalan, A. (2023). Anxiety symptoms and disorders during the COVID-19 pandemic in children and adolescents: Systematic review and meta-analysis. The European Journal of Psychiatry , 37 (4), 100218. Perestelo-Perez, L., Barraca, J., Peñate, W., Rivero-Santana, A., & Alvarez-Perez, Y. (2017). Mindfulness-based interventions for the treatment of depressive rumination: Systematic review and meta-analysis. International Journal of Clinical and Health Psychology , 17 (3), 282–295. https://doi.org/10.1016/j.ijchp.2017.07.004 Pescosolido, B. A., Halpern-Manners, A., Luo, L., & Perry, B. (2021). Trends in public stigma of mental illness in the US, 1996-2018. JAMA Network Open , 4 (12), e2140202–e2140202. *Pettit, G. S., Bates, J. E., Dodge, K. A., & Meece, D. W. (1999). The impact of after‐school peer contact on early adolescent externalizing problems is moderated by parental monitoring, perceived neighborhood safety, and prior adjustment. Child Development , 70 (3), 768–778. Piao, J., Huang, Y., Han, C., Li, Y., Xu, Y., Liu, Y., & He, X. (2022). Alarming changes in the global burden of mental disorders in children and adolescents from 1990 to 2019: A systematic analysis for the Global Burden of Disease study. European Child & Adolescent Psychiatry , 31 (11), 1827–1845. https://doi.org/10.1007/s00787-022-02040-4 *Prinzie, P., Onghena, P., & Hellinckx, W. (2005). Parent and child personality traits and children’s externalizing problem behavior from age 4 to 9 years: A cohort-sequential latent growth curve analysis. Merrill-Palmer Quarterly (1982-) , 335–366. *Prinzie, P., Onghena, P., & Hellinckx, W. (2006). A cohort-sequential multivariate latent growth curve analysis of normative CBCL aggressive and delinquent problem behavior: Associations with harsh discipline and gender. International Journal of Behavioral Development , 30 (5), 444–459. https://doi.org/10.1177/0165025406071901 *Propper, C. B., McLaughlin, K., Goldblum, J., Camerota, M., Gueron-Sela, N., Mills-Koonce, W. R., & Wagner, N. J. (2022). Parenting and maternal reported child sleep problems in infancy predict school-age aggression and inattention. Sleep Health , 8 (1), 62–68. Protzko, J. (2020). Kids These Days! Increasing delay of gratification ability over the past 50 years in children. Intelligence , 80 , 101451. Protzko, J., & Schooler, J. W. (2019). Kids these days: Why the youth of today seem lacking. Science Advances , 5 (10), eaav5916. Protzko, J., & Schooler, J. W. (2022). Who denigrates today’s youth?: The role of age, implicit theories, and sharing the same negative trait. Frontiers in Psychology , 13 , 723515. *Quaak, I., De Cock, M., De Boer, M., Lamoree, M., Leonards, P., & Van de Bor, M. (2016). Prenatal exposure to perfluoroalkyl substances and behavioral development in children. International Journal of Environmental Research and Public Health , 13 (5), 511. R Core Team. (2021). R: A language and environment for statistical computing. R Foundation for Statistical Computing [Computer software]. https://www.R-project.org/ *Raadal, M., Milgrom, P., Cauce, A. M., & Mancl, L. (1994). Behavior problems in 5− to 11-year-old children from low-income families. Journal of the American Academy of Child & Adolescent Psychiatry , 33 (7), 1017–1025. Raley, R. K., & Sweeney, M. M. (2020). Divorce, repartnering, and stepfamilies: A decade in review. Journal of Marriage and Family , 82 (1), 81–99. *Reijneveld, S. A., De Kleine, M., van Baar, A. L., Kollée, L. A., Verhaak, C. M., Verhulst, F. C., & Verloove-Vanhorick, S. P. (2006). Behavioural and emotional problems in very preterm and very low birthweight infants at age 5 years. Archives of Disease in Childhood-Fetal and Neonatal Edition , 91 (6), F423–F428. *Reijneveld, S. A., Wiegersma, P. A., Ormel, J., Verhulst, F. C., Vollebergh, W. A., & Jansen, D. E. (2014). Adolescents’ use of care for behavioral and emotional problems: Types, trends, and determinants. PLoS One , 9 (4), e93526. Rescorla, L. A., Achenbach, T. M., Ginzburg, S., Ivanova, M., Dumenci, L., Almqvist, F., Bathiche, M., Bilenberg, N., Bird, H., Domuta, A., Erol, N., Fombonne, E., Fonseca, A., Frigerio, A., Kanbayashi, Y., Lambert, M. C., Liu, X., Leung, P., Minaei, A., … Verhulst, F. (2007). Consistency of Teacher-Reported Problems for Students in 21 Countries. School Psychology Review , 36 (1), 91–110. https://doi.org/10.1080/02796015.2007.12087954 Rescorla, L. A., Achenbach, T. M., Ivanova, M. Y., Harder, V. S., Otten, L., Bilenberg, N., Bjarnadottir, G., Capron, C., De Pauw, S. S. W., Dias, P., Dobrean, A., Döpfner, M., Duyme, M., Eapen, V., Erol, N., Esmaeili, E. M., Ezpeleta, L., Frigerio, A., Fung, D. S. S., … Verhulst, F. C. (2011). International Comparisons of Behavioral and Emotional Problems in Preschool Children: Parents’ Reports From 24 Societies. Journal of Clinical Child & Adolescent Psychology , 40 (3), 456–467. https://doi.org/10.1080/15374416.2011.563472 Rescorla, L. A., Althoff, R. R., Ivanova, M. Y., & Achenbach, T. M. (2019). Effects of society and culture on parents’ ratings of children’s mental health problems in 45 societies. European Child & Adolescent Psychiatry , 28 (8), 1107–1115. https://doi.org/10.1007/s00787-018-01268-3 Rescorla, L., Achenbach, T. M., Ivanova, M. Y., Dumenci, L., Almqvist, F., Bilenberg, N., Bird, H., Broberg, A., Dobrean, A., Döpfner, M., Erol, N., Forns, M., Hannesdottir, H., Kanbayashi, Y., Lambert, M. C., Leung, P., Minaei, A., Mulatu, M. S., Novik, T. S., … Verhulst, F. (2007). Epidemiological comparisons of problems and positive qualities reported by adolescents in 24 countries. Journal of Consulting and Clinical Psychology , 75 (2), 351–358. https://doi.org/10.1037/0022-006X.75.2.351 *Riva, A., Nacinovich, R., Brivio, E., Mapelli, F., Rossi, S. M., Neri, F., & Bomba, M. (2018). Psychopathological risk in a sample of immigrant preadolescents in Italy. Minerva Pediatrica , 04959–9. Robinson, W. S. (1950). Ecological Correlations and the Behavior of Individuals. American Sociological Review , 15 (3), 351–357. https://doi.org/10.2307/2087176 *Rodriguez, M. C., Wade, T. J., Veldhuizen, S., Missiuna, C., Timmons, B., & Cairney, J. (2019). Emotional and behavioral problems in 4-and 5-year old children with and without motor delays. Frontiers in Pediatrics , 7 , 474. Rood, L., Roelofs, J., Bögels, S. M., & Arntz, A. (2012). The Effects of Experimentally Induced Rumination, Positive Reappraisal, Acceptance, and Distancing When Thinking About a Stressful Event on Affect States in Adolescents. Journal of Abnormal Child Psychology , 40 (1), 73–84. https://doi.org/10.1007/s10802-011-9544-0 *Roussos, A., Francis, K., Zoubou, V., Kiprianos, S., Prokopiou, A., & Richardson, C. (2001). The standardization of Achenbach’s Youth Self-Report in Greece in a national sample of high school students. European Child & Adolescent Psychiatry , 10 , 47–53. *Roussos, A., Karantanos, G., Richardson, C., Hartman, C., Karajiannis, D., Kyprianos, S., Lazaratou, H., Mahaira, O., Tassi, M., & Zoubou, V. (1999). Achenbach’s Child Behavior Checklist and Teachers’ Report Form in a normative sample of Greek children 6–12 years old. European Child & Adolescent Psychiatry , 8 (3), 165–172. *Rudan, V., Begovac, I., Szirovicza, L., Filipović, O., & Skočić, M. (2005). The child behavior checklist, teacher report form and youth self report problem scales in a normative sample of Croatian children and adolescents aged 7–18. Collegium Antropologicum , 29 (1), 17–26. Russell, G., Kelly, S., & Golding, J. (2010). A qualitative analysis of lay beliefs about the aetiology and prevalence of autistic spectrum disorders. Child: Care, Health and Development , 36 (3), 431–436. https://doi.org/10.1111/j.1365-2214.2009.00994.x *Rutherford, C., Sharp, H., Hill, J., Pickles, A., & Taylor-Robinson, D. (2019). How does perinatal maternal mental health explain early social inequalities in child behavioural and emotional problems? Findings from the Wirral child health and development study. PloS One , 14 (5), e0217342. Rutter, M., & Smith, D. J. (1997). Psychosocial disorders in young people: time trends and their cause. British Journal of Educational Studies, 45(3), 306-336. httős://doi.org/10.1111/1467-8527.t01-1-00054 Sahranavard, S., Esmaeili, A., Dastjerdi, R., & Salehiniya, H. (2018). The effectiveness of stress-management-based cognitive-behavioral treatments on anxiety sensitivity, positive and negative affect and hope. BioMedicine , 8 (4). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6254097/ *Salum, G. A., Mogg, K., Bradley, B. P., Stringaris, A., Gadelha, A., Pan, P. M., Rohde, L. A., Polanczyk, G. V., Manfro, G. G., Pine, D. S., & Leibenluft, E. (2017). Association between irritability and bias in attention orienting to threat in children and adolescents. Journal of Child Psychology and Psychiatry, and Allied Disciplines , 58 (5), 595–602. https://doi.org/10.1111/jcpp.12659 *Sampasa-Kanyinga, H., Colman, I., Goldfield, G. S., Janssen, I., Wang, J., Tremblay, M. S., Barnes, J. D., Walsh, J. J., & Chaput, J.-P. (2021). 24-hour movement behaviors and internalizing and externalizing behaviors among youth. Journal of Adolescent Health , 68 (5), 969–977. *Sandoval, M., Lemos, S., & Vallejo, G. (2006). Self-reported competences and problems in Spanish adolescents: A normative study of the YSR. Psicothema , 804–809. *Santos, I. S., Matijasevich, A., Capilheira, M. F., Anselmi, L., & Barros, F. C. (2015). Excessive crying at 3 months of age and behavioural problems at 4 years age: A prospective cohort study. Journal of Epidemiology and Community Health , 69 (7), 654–659. https://doi.org/10.1136/jech-2014-204568 Sawhill, E. K. and I. V. (2016, September 13). How free time became screen time. Brookings . https://www.brookings.edu/blog/social-mobility-memos/2016/09/13/how-free-time-became-screen-time/ Schepman, K., Collishaw, S., Gardner, F., Maughan, B., Scott, J., & Pickles, A. (2011). Do changes in parent mental health explain trends in youth emotional problems? Social Science & Medicine (1982) , 73 (2), 293–300. https://doi.org/10.1016/j.socscimed.2011.05.015 Schiavone, N., Virta, M., Leppämäki, S., Launes, J., Vanninen, R., Tuulio-Henriksson, A., Immonen, S., Järvinen, I., Lehto, E., Michelsson, K., & Hokkanen, L. (2019). ADHD and subthreshold symptoms in childhood and life outcomes at 40 years in a prospective birth-risk cohort. Psychiatry Research , 281 , 112574. https://doi.org/10.1016/j.psychres.2019.112574 Schiffrin, H. H., Godfrey, H., Liss, M., & Erchull, M. J. (2015). Intensive parenting: Does it have the desired impact on child outcomes? Journal of Child and Family Studies , 24 , 2322–2331. Schmuck, D. (2013). Single parenting: Fewer negative effects of children’s behaviors than claimed. Modern Psychological Studies , 18 (2), 12. Schwarzer, G. (2007). meta: An R package for meta-analysis. R News , 7 (3), 40–45. Sellers, R., Maughan, B., Pickles, A., Thapar, A., & Collishaw, S. (2015). Trends in parent‐ and teacher‐rated emotional, conduct and ADHD problems and their impact in prepubertal children in G reat B ritain: 1999–2008. Journal of Child Psychology and Psychiatry , 56 (1), 49–57. https://doi.org/10.1111/jcpp.12273 *Shahini, M., Rescorla, L. A., Ahmeti, A. P., Begovac, I., Dobrean, A., Markovıć, J., Rudan, V., Wancata, J., Wolanczyk, T., Zhjeqi, V., & Zukauskiene, R. (2015). Parent-reported behavioural and emotional problems in Albanian Kosovar children. Epidemiology and Psychiatric Sciences , 24 (3), 266–273. https://doi.org/10.1017/S204579601400016X Shaikh, E. A., & Shinde, V. R. (2018). Gender differences in internalized and externalized behavioral problems among school going children. Indian Journal of Health and Well-Being , 9 (3), 584–589. Shankman, S. A., Lewinsohn, P. M., Klein, D. N., Small, J. W., Seeley, J. R., & Altman, S. E. (2009). Subthreshold conditions as precursors for full syndrome disorders: A 15-year longitudinal study of multiple diagnostic classes. Journal of Child Psychology and Psychiatry , 50 (12), 1485–1494. https://doi.org/10.1111/j.1469-7610.2009.02117.x *Shin, K. M., Cho, S.-M., Shin, Y. M., & Park, K. S. (2016). Effects of early childhood peer relationships on adolescent mental health: A 6-to 8-year follow-up study in South Korea. Psychiatry Investigation , 13 (4), 383. Shooshtari, S., Brownell, M., Dik, N., Chateau, D., Yu, C. T., Mills, R. S., Burchill, C. A., & Wetzel, M. (2014). A population-based longitudinal study of depression in children with developmental disabilities in Manitoba. Journal of Mental Health Research in Intellectual Disabilities , 7 (3), 191–207. *Sivertsen, B., Harvey, A. G., Reichborn-Kjennerud, T., Torgersen, L., Ystrom, E., & Hysing, M. (2015). Later emotional and behavioral problems associated with sleep problems in toddlers: A longitudinal study. JAMA Pediatrics , 169 (6), 575–582. Smedje, H., Broman, J.-E., Hetta, J., & von Knorring, A.-L. (1999). Psychometric properties of a Swedish version of the “Strengths and Difficulties Questionnaire”. European Child & Adolescent Psychiatry , 8 (2), 63–70. https://doi.org/10.1007/s007870050086 Sondeijker, F. E., Ferdinand, R. F., Oldehinkel, A. J., Veenstra, R., Tiemeier, H., Ormel, J., & Verhulst, F. C. (2007). Disruptive behaviors and HPA-axis activity in young adolescent boys and girls from the general population. Journal of Psychiatric Research , 41 (7), 570–578. *Sourander, A. (2001). Emotional and behavioural problems in a sample of Finnish three-year-olds. European Child & Adolescent Psychiatry , 10 (2), 98–104. https://doi.org/10.1007/s007870170032 *Sourander, A., Helstelä, L., & Helenius, H. (1999). Parent-adolescent agreement on emotional and behavioral problems. Social Psychiatry and Psychiatric Epidemiology , 34 , 657–663. *Steinhausen, H.-C., Bearth-Carrari, C., & Winkler Metzke, C. (2009). Psychosocial adaptation of adolescent migrants in a Swiss community survey. Social Psychiatry and Psychiatric Epidemiology , 44 , 308–316. *Steinhausen, H.-C., & Metzke, C. W. (2001). Risk, compensatory, vulnerability, and protective factors influencing mental health in adolescence. Journal of Youth and Adolescence , 30 (3), 259–280. *Steinhausen, H.-C., Metzke, C. W., Meier, M., & Kannenberg, R. (1997). Behavioral and emotional problems reported by parents for ages 6 to 17 in a Swiss epidemiological study. European Child & Adolescent Psychiatry , 6 (3), 136–141. *Stensen, K., Stenseng, F., Lydersen, S., de Wolff, M. S., Wallander, J., & Drugli, M. B. (2018). Screening for mental health problems in a Norwegian preschool population. A validation of the ages and stages questionnaire: Social‐emotional (ASQ: SE). Child and Adolescent Mental Health , 23 (4), 368–375. Stevanovic, D., Jafari, P., Knez, R., Franic, T., Atilola, O., Davidovic, N., Bagheri, Z., & Lakic, A. (2017). Can we really use available scales for child and adolescent psychopathology across cultures? A systematic review of cross-cultural measurement invariance data. Transcultural Psychiatry , 54 (1), 125–152. https://doi.org/10.1177/1363461516689215 *Stevens, G. W. J. M., Pels, T., Bengi-Arslan, L., Verhulst, F. C., Vollebergh, W. A. M., & Crijnen, A. A. M. (2003). Parent, teacher and self-reported problem behavior in The Netherlands: Comparing Moroccan immigrant with Dutch and with Turkish immigrant children and adolescents. Social Psychiatry and Psychiatric Epidemiology , 38 (10), 576–585. https://doi.org/10.1007/s00127-003-0677-5 Su, Q., & Liu, G. (2020). Birth cohort changes in the subjective well-being of Chinese college students: A cross-temporal meta-analysis, 2002–2017. Frontiers in Psychology , 11 , 1011. Sullivan, P. F., Agrawal, A., Bulik, C. M., Andreassen, O. A., Børglum, A. D., Breen, G., Cichon, S., Edenberg, H. J., Faraone, S. V., Gelernter, J., Mathews, C. A., Nievergelt, C. M., Smoller, J. W., O'Donovan, M. C., & Psychiatric Genomics Consortium. (2018). Psychiatric genomics: An update and an agenda. The American Journal of Psychiatry, 175 (1), 15–27. https://doi.org/10.1176/appi.ajp.2017.17030283 *Tehrani-Doost, M., Shahrivar, Z., Pakbaz, B., Rezaie, A., & Ahmadi, F. (2011). Normative data and psychometric properties of the child behavior checklist and teacher rating form in an Iranian community sample. Iranian Journal of Pediatrics , 21 (3), 331. *Tepper, P., Liu, X., Guo, C., Zhai, J., Liu, T., & Li, C. (2008). Depressive symptoms in Chinese children and adolescents: Parent, teacher, and self reports. Journal of Affective Disorders , 111 (2–3), 291–298. *Theunissen, M. H., Klein Velderman, M., Cloostermans, A. P., & Reijneveld, S. A. (2017). Emotional and behavioural problems in young children with divorced parents. The European Journal of Public Health , 27 (5), 840–845. Tick, N. T., Van Der Ende, J., & Verhulst, F. C. (2007). Twenty-year trends in emotional and behavioral problems in Dutch children in a changing society. Acta Psychiatrica Scandinavica , 116 (6), 473–482. *Tolmunen, T., Honkalampi, K., Hintikka, J., Rissanen, M.-L., Maaranen, P., Kylmä, J., & Laukkanen, E. (2010). Adolescent dissociation and alexithymia are distinctive but overlapping phenomena. Psychiatry Research , 176 (1), 40–44. https://doi.org/10.1016/j.psychres.2008.10.029 *Tong, L., Shi, H., & Li, X. (2017). Associations among ADHD, abnormal eating and overweight in a non-clinical sample of Asian children. Scientific Reports , 7 (1), 2844. *Tsotsi, S., Broekman, B. F., Shek, L. P., Tan, K. H., Chong, Y. S., Chen, H., Meaney, M. J., & Rifkin‐Graboi, A. E. (2019). Maternal parenting stress, child exuberance, and preschoolers’ behavior problems. Child Development , 90 (1), 136–146. Twenge, J. M. (2020). Increases in depression, self‐harm, and suicide among US adolescents after 2012 and links to technology use: Possible mechanisms. Psychiatric Research and Clinical Practice , 2 (1), 19–25. Twenge, J. M., Joiner, T. E., Rogers, M. L., & Martin, G. N. (2018). Increases in depressive symptoms, suicide-related outcomes, and suicide rates among US adolescents after 2010 and links to increased new media screen time. Clinical Psychological Science , 6 (1), 3–17. Twenge, J. M., Spitzberg, B. H., & Campbell, W. K. (2019). Less in-person social interaction with peers among U.S. adolescents in the 21st century and links to loneliness. Journal of Social and Personal Relationships , 36 (6), 1892–1913. https://doi.org/10.1177/0265407519836170 *Uddin, M. J., Ekstrøm, C. T., Hemager, N., Christiani, C. A., Gregersen, M., Ellersgaard, D. V., Spang, K. S., Greve, A., Gantriis, D. L., & Burton, B. K. (2021). Is the Association Between Parents’ Mental Illness and Child Psychopathology Mediated via Home Environment and Caregiver’s Psychosocial Functioning? A Mediation Analysis of the Danish High Risk and Resilience Study—VIA7, a Population-Based Cohort Study. Schizophrenia Bulletin Open , 2 (1), sgab024. *Uljas, H., Rautava, P., Helenius, H., & Sillanpää, M. (1999). Behaviour of Finnish 3-year-old children. I: Effects of sociodemographic factors, mother’s health, and pregnancy outcome. Developmental Medicine and Child Neurology , 41 (6), 412–419. https://doi.org/10.1017/s0012162299000882 Universities UK. (2018). Minding our future: Starting a conversation about the support of student mental health . https://www.universitiesuk.ac.uk/what-we-do/policy-and-research/publications/minding-our-future-starting-conversation van der Ende, J., Verhulst, F. C., & Tiemeier, H. (2012). Agreement of informants on emotional and behavioral problems from childhood to adulthood. Psychological Assessment , 24 (2), 293. *van Zeijl, J., Mesman, J., Stolk, M. N., Alink, L. R. A., van Ijzendoorn, M. H., Bakermans-Kranenburg, M. J., Juffer, F., & Koot, H. M. (2006). Terrible ones? Assessment of externalizing behaviors in infancy with the Child Behavior Checklist. Journal of Child Psychology and Psychiatry, and Allied Disciplines , 47 (8), 801–810. https://doi.org/10.1111/j.1469-7610.2006.01616.x *Vásquez-Echeverría, A., Alvarez-Nuñez, L., González, M., & Rudnitzky, F. (2020). Behavioural problems in a nationally representative sample of Uruguay. Characterisation of latent profiles by socioeconomic status, maternal depression and family violence. Child Psychiatry & Human Development , 51 , 801–812. *Vassi, I., Veltsista, A., Lagona, E., Gika, A., Kavadias, G., & Bakoula, C. (2008). The generation gap in numbers: Parent-child disagreement on youth’s emotional and behavioral problems: A Greek community based-survey. Social Psychiatry and Psychiatric Epidemiology , 43 (12), 1008–1013. https://doi.org/10.1007/s00127-008-0389-y *Veldman, K., Bültmann, U., Stewart, R. E., Ormel, J., Verhulst, F. C., & Reijneveld, S. A. (2014). Mental health problems and educational attainment in adolescence: 9-year follow-up of the TRAILS study. PloS One , 9 (7), e101751. Vergunst, F., Tremblay, R. E., Galera, C., Nagin, D., Vitaro, F., Boivin, M., & Côté, S. M. (2019). Multi-rater developmental trajectories of hyperactivity–impulsivity and inattention symptoms from 1.5 to 17 years: A population-based birth cohort study. European Child & Adolescent Psychiatry , 28 , 973–983. *Verhulst, F. C., & Akkerhuis, G. W. (1986). Mental health in Dutch children: (III). Behavioral-emotional problems reported by teachers of children aged 4-12. Acta Psychiatrica Scandinavica. Supplementum , 330 , 1–74. https://doi.org/10.1111/j.1600-0447.1986.tb10564.x *Veríssimo, L., Dias, P., Santos, E., & Ortigão, S. (2020). Academic achievement and internalizing problems in primary and secondary school students in Portugal. Educacao e Pesquisa , 46 . https://doi.org/10.1590/S1678-4634202046218667 *Verlinden, M., Veenstra, R., Ghassabian, A., Jansen, P. W., Hofman, A., Jaddoe, V. W. V., Verhulst, F. C., & Tiemeier, H. (2014). Executive Functioning and Non-Verbal Intelligence as Predictors of Bullying in Early Elementary School. Journal of Abnormal Child Psychology , 42 (6), 953–966. https://doi.org/10.1007/s10802-013-9832-y Viechtebauer, W. (2021). Metaphor package for R software. [Computer software]. https://www.metafor-project.org/doku.php/metafor *Viola, L., Garrido, G., & Rescorla, L. (2011). Testing multicultural robustness of the Child Behavior Checklist in a national epidemiological sample in Uruguay. Journal of Abnormal Child Psychology , 39 (6), 897–908. https://doi.org/10.1007/s10802-011-9500-z Vuong, A. T., Jarman, H. K., Doley, J. R., & McLean, S. A. (2021). Social media use and body dissatisfaction in adolescents: The moderating role of thin-and muscular-ideal internalisation. International Journal of Environmental Research and Public Health , 18 (24), 13222. *Waenerlund, A., Stenmark, H., Bergström, E., Hägglöf, B., Öhman, A., & Petersen, S. (2016). School experiences may be important determinants of mental health problems in middle childhood–a Swedish longitudinal population‐based study. Acta Paediatrica , 105 (4), 407–415. *Wang, Q. (2014). Analysis of related factors in children with behavior problems. Energy Education Science and Technology Part A: Energy Science and Research , 32 (6), Article 6. Watkins, E., & Baracaia, S. (2002). Rumination and social problem-solving in depression. Behaviour Research and Therapy , 40 (10), 1179–1189. https://doi.org/10.1016/S0005-7967(01)00098-5 *Weine, A. M., Phillips, J. S., & Achenbach, T. M. (1995). Behavioral and emotional problems among Chinese and American children: Parent and teacher reports for ages 6 to 13. Journal of Abnormal Child Psychology , 23 (5), 619–639. https://doi.org/10.1007/BF01447666 *Weiss, B., Dang, M., Trung, L., Nguyen, M. C., Thuy, N. T. H., & Pollack, A. (2014). A nationally representative epidemiological and risk factor assessment of child mental health in Vietnam. International Perspectives in Psychology , 3 (3), 139–153. *Wesselhoeft, R., Davidsen, K., Sibbersen, C., Kyhl, H., Talati, A., Andersen, M. S., & Bilenberg, N. (2021). Maternal prenatal stress and postnatal depressive symptoms: Discrepancy between mother and teacher reports of toddler psychological problems. Social Psychiatry and Psychiatric Epidemiology , 56 (4), 559–570. https://doi.org/10.1007/s00127-020-01964-z Whipp, A. M., Vuoksimaa, E., Bolhuis, K., de Zeeuw, E. L., Korhonen, T., Mauri, M., Pulkkinen, L., Rimfeld, K., Rose, R. J., & Beijsterveldt, C. (Toos) E. van. (2021). Teacher-rated aggression and co-occurring behaviors and emotional problems among schoolchildren in four population-based European cohorts. PLoS One , 16 (4), e0238667. *White, L. K., Degnan, K. A., Henderson, H. A., Pérez‐Edgar, K., Walker, O. L., Shechner, T., Leibenluft, E., Bar‐Haim, Y., Pine, D. S., & Fox, N. A. (2017). Developmental relations among behavioral inhibition, anxiety, and attention biases to threat and positive information. Child Development , 88 (1), 141–155. *White, T., Muetzel, R. L., El Marroun, H., Blanken, L. M. E., Jansen, P., Bolhuis, K., Kocevska, D., Mous, S. E., Mulder, R., Jaddoe, V. W. V., van der Lugt, A., Verhulst, F. C., & Tiemeier, H. (2018). Paediatric population neuroimaging and the Generation R Study: The second wave. European Journal of Epidemiology , 33 (1), Article 1. https://doi.org/10.1007/s10654-017-0319-y Wiggers, M., & Paas, F. (2022). Harsh physical discipline and externalizing behaviors in children: A systematic review. International Journal of Environmental Research and Public Health , 19 (21), 14385. *Wildeboer, A., Thijssen, S., Van IJzendoorn, M. H., Van Der Ende, J., Jaddoe, V. W., Verhulst, F. C., Hofman, A., White, T., Tiemeier, H., & Bakermans-Kranenburg, M. J. (2015). Early childhood aggression trajectories: Associations with teacher-reported problem behaviour. International Journal of Behavioral Development , 39 (3), 221–234. Wongupparaj, P., Wongupparaj, R., Kumari, V., & Morris, R. G. (2017). The Flynn effect for verbal and visuospatial short-term and working memory: A cross-temporal meta-analysis. Intelligence , 64 , 71–80. *Wright, N., Courchesne, V., Pickles, A., Bedford, R., Duku, E., Kerns, C. M., Bennett, T., Georgiades, S., Hill, J., Richard, A., Sharp, H., Smith, I. M., Vaillancourt, T., Zaidman-Zait, A., Zwaigenbaum, L., Szatmari, P., & Elsabbagh, M. (2023). A longitudinal comparison of emotional, behavioral and attention problems in autistic and typically developing children. Psychological Medicine , 1–13. https://doi.org/10.1017/S0033291723001599 *Wu, Y.-T., Chen, W. J., Hsieh, W.-S., Chen, P.-C., Liao, H.-F., Su, Y.-N., & Jeng, S.-F. (2012). Maternal-reported behavioral and emotional problems in Taiwanese preschool children. Research in Developmental Disabilities , 33 (3), 866–873. https://doi.org/10.1016/j.ridd.2011.11.018 *Xerxa, Y., Rescorla, L. A., Serdarevic, F., Van IJzendorn, M. H., Jaddoe, V. W., Verhulst, F. C., Luijk, M. P., & Tiemeier, H. (2020). The complex role of parental separation in the association between family conflict and child problem behavior. Journal of Clinical Child & Adolescent Psychology , 49 (1), 79–93. *Xue, Y., Leventhal, T., Brooks-Gunn, J., & Earls, F. J. (2005). Neighborhood residence and mental health problems of 5-to 11-year-olds. Archives of General Psychiatry , 62 (5), 554–563. *Yang, H.-J., Soong, W.-T., Chiang, C.-N., & Chen, W. J. (2000). Competence and behavioral/emotional problems among Taiwanese adolescents as reported by parents and teachers. Journal of the American Academy of Child & Adolescent Psychiatry , 39 (2), 232–239. Yang, Y., Cao, S., Shields, G. S., Teng, Z., & Liu, Y. (2017). The relationships between rumination and core executive functions: A meta-analysis. Depression and Anxiety , 34 (1), 37–50. https://doi.org/10.1002/da.22539 Yazdani, M., Rezaei, S., & Pahlavanzadeh, S. (2010). The effectiveness of stress management training program on depression, anxiety and stress of the nursing students. Iranian Journal of Nursing and Midwifery Research , 15 (4), 208. *Yunis, F., Eapen, V., Zoubeidi, T., & Yousef, S. (2007). Psychometric properties of the Child Behavior Checklist/2-3 in an Arab population. Psychological Reports , 100 (3 Pt 1), 771–776. https://doi.org/10.2466/pr0.100.3.771-776 Zalewski, M., Lengua, L. J., Fisher, P. A., Trancik, A., Bush, N. R., & Meltzoff, A. N. (2012). Poverty and single parenting: Relations with preschoolers’ cortisol and effortful control. Infant and Child Development , 21 (5), 537–554. *Zandstra, A. R. E., Ormel, J., Dietrich, A., van den Heuvel, E. R., Hoekstra, P. J., & Hartman, C. A. (2018). Sensitivity to psychosocial chronic stressors and adolescents’ externalizing problems: Combined moderator effects of resting heart rate and parental psychiatric history. Biological Psychology , 134 , 20–29. Zerwas, S., Holle, A. V., Watson, H., Gottfredson, N., & Bulik, C. M. (2014). Childhood anxiety trajectories and adolescent disordered eating: Findings from the NICHD study of early child care and youth development. International Journal of Eating Disorders , 47 (7), 784–792. Zhao, M. Z., Song, X. S., & Ma, J. S. (2021). Gene× environment interaction in major depressive disorder. World Journal of Clinical Cases , 9 (31), 9368. Zhao, Z., Wan, R., & Ma, J. (2022). Social change and birth cohorts decreased resilience among college students in China: A cross-temporal meta-analysis, 2007–2020. Personality and Individual Differences , 196 , 111716. Zheng, H., & Echave, P. (2021). Are recent cohorts getting worse? Trends in US adult physiological status, mental health, and health behaviors across a century of birth cohorts. American Journal of Epidemiology , 190 (11), 2242-2255. Zhong, Q., Niu, L., Chen, K., Lee, T. M. C., & Zhang, R. (2024). Prevalence and risk of subthreshold anxiety developing into threshold anxiety disorder in the general population. Journal of Affective Disorders , 367 , 815–822. https://doi.org/10.1016/j.jad.2024.09.031 *Zhu, Z., Shen, J., Zhu, Y., Wang, L., Qi, Q., Wang, X., Li, C., Andegiorgish, A. K., Elhoumed, M., Cheng, Y., Dibley, M. J., & Zeng, L. (2022). Head circumference trajectories during the first two years of life and cognitive development, emotional, and behavior problems in adolescence: A cohort study. European Journal of Pediatrics , 181 (9), 3401–3411. https://doi.org/10.1007/s00431-022-04554-0 Zoellner, F., Erhart, M., Napp, A. K., Reiss, F., Devine, J., Kaman, A., & Ravens-Sieberer, U. (2024). Risk and protective factors for mental health problems in children and adolescents during the COVID-19 pandemic: results of the longitudinal COPSY study. European Child & Adolescent Psychiatry , 1-11. *Zondervan‐Zwijnenburg, M. A., Veldkamp, S. A., Neumann, A., Barzeva, S. A., Nelemans, S. A., van Beijsterveldt, C. E., Branje, S. J., Hillegers, M. H., Meeus, W. H., & Tiemeier, H. (2020). Parental age and offspring childhood mental health: A multi‐cohort, population‐based investigation. Child Development , 91 (3), 964–982. *Zubeidat, I., Dallasheh, W., Fernández-Parra, A., Sierra, J. C., & Salinas, J. M. (2018). Youth self-report factor structure: Detecting sex and age differences in emotional and behavioral problems among Spanish school adolescent sample. Int’l J. Soc. Sci. Stud. , 6 , 35. *Zukauskiene, R., Ignataviciene, K., & Daukantaité, D. (2003). Subscales scores of the Lithuanian version of CBCL. European Child & Adolescent Psychiatry , 12 (3), 136–143. Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterials.docx ExtendedData.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7905820","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Systematic Review","associatedPublications":[],"authors":[{"id":554737176,"identity":"6323d66d-c100-437e-b1ba-2ac3b8f2fc41","order_by":0,"name":"Boglarka Vekety","email":"","orcid":"","institution":"Eötvös Loránd University","correspondingAuthor":false,"prefix":"","firstName":"Boglarka","middleName":"","lastName":"Vekety","suffix":""},{"id":554737178,"identity":"fa9947a6-99de-449c-9aaf-3b320f3e13b9","order_by":1,"name":"Tamas Koi","email":"","orcid":"","institution":"Semmelweis University","correspondingAuthor":false,"prefix":"","firstName":"Tamas","middleName":"","lastName":"Koi","suffix":""},{"id":554737179,"identity":"768249fa-f241-4c86-9cb5-54a1b8815669","order_by":2,"name":"Alexander H. N. Logemann","email":"","orcid":"","institution":"Eötvös Loránd University","correspondingAuthor":false,"prefix":"","firstName":"Alexander","middleName":"H. N.","lastName":"Logemann","suffix":""},{"id":554737181,"identity":"e21b4e00-ab3c-4a76-8708-9ef93344b6de","order_by":3,"name":"John Protzko","email":"","orcid":"","institution":"Central Connecticut State University","correspondingAuthor":false,"prefix":"","firstName":"John","middleName":"","lastName":"Protzko","suffix":""},{"id":554737182,"identity":"7adddd7f-108d-491f-b00b-4c264f8b2822","order_by":4,"name":"Heather C. Whalley","email":"","orcid":"","institution":"University of Edinburgh","correspondingAuthor":false,"prefix":"","firstName":"Heather","middleName":"C.","lastName":"Whalley","suffix":""},{"id":554737185,"identity":"11438303-c3ba-4b89-a35c-dae9307ddd49","order_by":5,"name":"Zsofia K. Takacs","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYNACAwY5BoYEKJNILQbGpGphMEhsIFqLfP/iZx9+FPxJ72dPYPzwg+GwMUEtjDOeGc/sMTDIndnzgFmyh+GwGUEtzBIHjBl4gFo23EhgkGZgOGxDUAubxPHPjH8MDNLtbyQw/yZKCw9/jzEz0JYEA4kENpAthB0mIcFTzCxjYGw448zDNsseg3TC3pfvP76Z8c0fOXn+9uTDN35UWBs2ELYmAcZibCAyIvkPEKNqFIyCUTAKRjQAAGfcNQoXvCpPAAAAAElFTkSuQmCC","orcid":"","institution":"University of Edinburgh","correspondingAuthor":true,"prefix":"","firstName":"Zsofia","middleName":"K.","lastName":"Takacs","suffix":""}],"badges":[],"createdAt":"2025-10-20 12:53:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7905820/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7905820/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98424229,"identity":"4fda23f9-d0bf-4396-ac68-879402051e23","added_by":"auto","created_at":"2025-12-17 16:33:05","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":957227,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.docx","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/53b801c36503d96754f966fd.docx"},{"id":98422478,"identity":"55c88923-2d58-42d5-81c2-c84ef85241a0","added_by":"auto","created_at":"2025-12-17 16:31:04","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8783,"visible":true,"origin":"","legend":"","description":"","filename":"bb0081d152794a6c8bf95aea6188f8ab.json","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/2093cd5a678f36d68212ab71.json"},{"id":98423143,"identity":"65a14a65-cd81-4279-8493-ca4681968594","added_by":"auto","created_at":"2025-12-17 16:31:52","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":173728,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/fea12e3a5a94aede7bc36a2c.docx"},{"id":98422845,"identity":"78db3b34-e50e-47a3-a16d-e57c4491b987","added_by":"auto","created_at":"2025-12-17 16:31:34","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":897604,"visible":true,"origin":"","legend":"","description":"","filename":"bb0081d152794a6c8bf95aea6188f8ab1enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/5508cb20822c7cf6bb41d1f2.xml"},{"id":97965437,"identity":"e04a21b8-ff72-46ee-8f7c-96a8320db18b","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":311911,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/4b517d715ac4b4c041727a81.png"},{"id":98423068,"identity":"56da6c0f-8224-401c-9eb9-5ad7965fa414","added_by":"auto","created_at":"2025-12-17 16:31:48","extension":"jpeg","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":34367,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/ec36944602ef76653b3a7d4b.jpeg"},{"id":98424009,"identity":"f8813c0f-3ab4-4090-9db0-4ed11394ea89","added_by":"auto","created_at":"2025-12-17 16:32:51","extension":"jpeg","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":109425,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage11.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/3f74ccbec8959f70194a3bde.jpeg"},{"id":97965441,"identity":"a5ef1fed-b9d3-4727-b88a-60c7d1e3e76f","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"jpeg","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":40244,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage12.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/c55eb973d09196b61aa720ab.jpeg"},{"id":97965450,"identity":"252c99ea-87ad-4d58-95d6-90de93d0c37f","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"jpeg","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":181124,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage13.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/bbdeaf1342071b7828575495.jpeg"},{"id":98423971,"identity":"8fe5d7ea-0e0f-44f4-9c6e-cbcaa061b3b4","added_by":"auto","created_at":"2025-12-17 16:32:48","extension":"jpeg","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":117528,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage14.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/6be43037797199c6708c41c9.jpeg"},{"id":98423093,"identity":"27482432-4514-4447-9f58-4d1a7837a3ca","added_by":"auto","created_at":"2025-12-17 16:31:51","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":70,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/8313f76badedb666f861a3be.png"},{"id":97965447,"identity":"30c6a3a0-bd53-4f70-ba4d-215c1d121bb5","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":70,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/d73c0393dc1275fb38329e90.png"},{"id":97965455,"identity":"58843d68-492b-48fb-8892-1b2a62fdb3d0","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":108143,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/684758d9734d07c79508eae4.png"},{"id":97965461,"identity":"48d285be-020a-4442-8673-44024f18ed29","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":40002,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/5d7fd3cf188d2add9c0a8f72.png"},{"id":98424208,"identity":"b1b0467d-b506-40b6-b5fd-383497510a6c","added_by":"auto","created_at":"2025-12-17 16:33:05","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":79660,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/f95f064f4fa68b846fb16f15.png"},{"id":98422502,"identity":"aaeea1a6-8151-4bee-aa10-da4f373de477","added_by":"auto","created_at":"2025-12-17 16:31:09","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":47960,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/d14cb0c9a1f1ee204e617849.png"},{"id":97965445,"identity":"60cbe2d1-849c-4fca-8319-d0c370e568d8","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"jpeg","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":131134,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/dfb612b423817a0a546c3331.jpeg"},{"id":98422994,"identity":"ae7fe5a6-c3aa-479f-87f0-e359108f1280","added_by":"auto","created_at":"2025-12-17 16:31:43","extension":"jpeg","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":154166,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/83d8b9421419c7e3a9b9531d.jpeg"},{"id":98422903,"identity":"97bd14bb-1a28-426d-8525-76f15459064d","added_by":"auto","created_at":"2025-12-17 16:31:38","extension":"jpeg","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":137729,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/25039b1ee7b0876999eb814c.jpeg"},{"id":98423101,"identity":"e917475b-ce3b-4012-9e58-5ed384841a2d","added_by":"auto","created_at":"2025-12-17 16:31:51","extension":"jpeg","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":108378,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage9.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/04147bf060fd823fe689f73b.jpeg"},{"id":98424346,"identity":"46a39030-1a9c-4a8d-a4f7-d463ec923a2e","added_by":"auto","created_at":"2025-12-17 16:33:14","extension":"png","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":108825,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/8ee22a41f5605016a8425808.png"},{"id":97965463,"identity":"64c8d982-352d-4354-9af7-bf5c74862a45","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7216,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/54fd9c35786bf6f6b82883d6.png"},{"id":97965459,"identity":"df6a0dd9-fcca-4186-bf40-f460a7870eb4","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":22513,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/be76aeb41fbbcce0df4cc04f.png"},{"id":98423025,"identity":"d1827125-2b5b-45b5-ad9e-3915123ec996","added_by":"auto","created_at":"2025-12-17 16:31:45","extension":"png","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8003,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/2701a8a1a3e7ad29af52d4fa.png"},{"id":97965469,"identity":"9566a7f5-6789-42bc-b778-8eca5a77b20f","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":34189,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/04d3ab057b4dd04a716298c5.png"},{"id":97965453,"identity":"ce2bb212-30c0-4353-8e9c-640a902c1221","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":18728,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/e0511ff82437b94e50c34d9b.png"},{"id":97965457,"identity":"0de48014-09f7-4acd-9c44-fa0693a75765","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":321,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/345407e4b666ca81a43ce24b.png"},{"id":97965467,"identity":"8d6b0699-4c27-477a-b3cf-fec1f3c5e48e","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":321,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage15.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/b02acd5a01b92f2de085dffe.png"},{"id":98423076,"identity":"4620922e-5c07-4ff3-a0b8-782d3c8b397a","added_by":"auto","created_at":"2025-12-17 16:31:48","extension":"png","order_by":28,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":24285,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/b9dc9e94b362a6d2d82df809.png"},{"id":98422868,"identity":"68387529-2421-436b-8838-7bdbbc025e75","added_by":"auto","created_at":"2025-12-17 16:31:36","extension":"png","order_by":29,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9495,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/4d504513f6e341bb3c76f830.png"},{"id":97965464,"identity":"3733994a-14e2-48ae-ba66-ce36dc9a9c8b","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":30,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":17076,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/be61d8ab58c107cc1f190922.png"},{"id":97965466,"identity":"83af2ef1-04d2-4f2c-be92-ddb29c889562","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":31,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14351,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/983760b489ae7992d129a77d.png"},{"id":98424216,"identity":"258ee775-c144-4725-b3bb-3b6cf4f132f6","added_by":"auto","created_at":"2025-12-17 16:33:05","extension":"png","order_by":32,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":26464,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/37896b47345de857232f6d12.png"},{"id":97965465,"identity":"67aea37a-5e28-4e5a-bd41-fad6a8ee8c8f","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":33,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32254,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/f0fe39a16f7d5cdd9f02b710.png"},{"id":97965471,"identity":"30595ff8-ed55-407d-babe-0d5c21a5bf42","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":34,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":22733,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/7c9cbf75e93ee9fa18eee42c.png"},{"id":97965462,"identity":"54becfb6-6d2b-41ad-b9c6-934381634539","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"png","order_by":35,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":21784,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/0189f6432e8dd28e413c32b8.png"},{"id":97965473,"identity":"198df8f1-d77a-4f45-9436-e862d057a554","added_by":"auto","created_at":"2025-12-11 09:48:55","extension":"xml","order_by":36,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":891938,"visible":true,"origin":"","legend":"","description":"","filename":"bb0081d152794a6c8bf95aea6188f8ab1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/2a869dc2880a58168eb41c76.xml"},{"id":98423187,"identity":"9311240f-91a8-4153-bc13-458595b85a7e","added_by":"auto","created_at":"2025-12-17 16:31:55","extension":"html","order_by":37,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":990767,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/ef15ec6f94c07e2ce85a20e4.html"},{"id":98423148,"identity":"455c9f24-5d49-40d6-a3d5-09128ed632b6","added_by":"auto","created_at":"2025-12-17 16:31:52","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":36603,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eScatterplots of Changes in Externalizing Problems by Parent Reports\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/7087a0a5f869266cb10f0d4e.jpg"},{"id":97965432,"identity":"8fd9ad54-9dee-46ea-aef6-f304883deb16","added_by":"auto","created_at":"2025-12-11 09:48:53","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":54353,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eScatterplots of Changes in Aggression by Parent and Self-Reports\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/0b31248882ceccd69e62fb3c.jpg"},{"id":97965435,"identity":"92017e35-d29b-400c-ae00-ea1e584c37ea","added_by":"auto","created_at":"2025-12-11 09:48:53","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":23986,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eScatterplot of Changes in Anxiety-Depression by Parent Reports\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/22f4d0d17beb5c3a424cbfbb.jpg"},{"id":97965443,"identity":"eb5b5ab7-9194-429e-aef7-ea1215a73751","added_by":"auto","created_at":"2025-12-11 09:48:54","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":32163,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eScatterplot of Changes in Attention Problems by Parent Reports\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/89201bb615d684511ad7440c.jpg"},{"id":98422985,"identity":"189da24e-2528-457c-b931-86549deb2df7","added_by":"auto","created_at":"2025-12-17 16:31:43","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":23576,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eScatterplot of Change in Thought Problems by Parent Reports\u003c/em\u003e\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/5fa8ad522d79233fe7458b8a.jpg"},{"id":98774622,"identity":"8b73829d-82ae-44ec-97e8-76977294497e","added_by":"auto","created_at":"2025-12-22 12:05:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2045622,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/2f231f32-2b9d-48f8-9a6e-ad2246b936ea.pdf"},{"id":97965536,"identity":"ee0cb358-6f10-46f6-88df-d7f8692042c6","added_by":"auto","created_at":"2025-12-11 09:49:16","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":173728,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/f543e4a7aac697526221bc52.docx"},{"id":97965433,"identity":"aaac31b0-2e09-41f3-b8b9-200ea411b06b","added_by":"auto","created_at":"2025-12-11 09:48:53","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":0,"visible":true,"origin":"","legend":"","description":"","filename":"ExtendedData.docx","url":"https://assets-eu.researchsquare.com/files/rs-7905820/v1/94d2a745ec413242ef19a259.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Kids These Days! A Cross-Temporal Meta-Analysis of Changes in Emotional and Behavioral Problems of Population-Based Samples Over the Past Decades","fulltext":[{"header":"Public Significance Statement","content":"\u003cp\u003eThis cross-temporal meta-analysis finds that \u0026rsquo;kids these days\u0026rsquo; have not been experiencing an overall decline in mental health over the past 40 years - contrary to common conception. However, there is strong evidence that the incidence of some emotional and behavioral problems has changed over the past decades. For example, aggression has decreased, while there is some evidence that attention and thought problems in children and teens, and anxiety-depression in teens might have increased.\u003c/p\u003e"},{"header":"Introduction","content":"\u003cp\u003eUnderstanding how emotional and behavioral problems in youth have changed over time is central to the broader study of mental health and psychopathology. Psychologists, educators, and policymakers are increasingly concerned with the apparent rise of mental health problems both in adults (e.g., Buecker et al., 2021; Zheng \u0026amp; Echave, 2021) and in children and adolescents (e.g., the Lancet Psychiatry Commission on youth mental health by McGorry et al., 2024). These concerns raise fundamental questions about the origins, development and classification of mental health disorders.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eA longstanding question is whether the observed increase in mental health disorder diagnoses simply reflects genuine changes in prevalence or is simply the result of improved detection and diagnostic practices, often referred to as the prevalence inflation hypothesis (Foulkes \u0026amp; Andrews, 2023). Addressing this issue requires not only an analysis of diagnostic trends but also a focus on underlying emotional and behavioral problems that precede clinical-level disorders. The present study definitively examines secular trends in emotional and behavioral problems that often precede formal diagnoses, among young people across the last decades. If mental health disorders are indeed increasing, one would also expect to see a concurrent increase in associated subclinical difficulties.\u003c/p\u003e\n\u003cp\u003eEmotional and behavioral problems is an umbrella term that includes psychological difficulties related to one\u0026rsquo;s emotions and behavior. When the severity of certain difficulties is high, one is diagnosed with a mental health disorder. However, two to three times more people experience these difficulties below the threshold of a clinical diagnosis as above (Haller et al., 2014; Johnson et al., 2022). Subthreshold psychopathology early in life through late adolescence increases the risk of developing mental health disorders later in life (Schiavone et al., 2019; Shankman et al., 2009; Zhong et al., 2024). These life stages are especially malleable, offering critical opportunities for interventions that support long-term mental health (Jones \u0026amp; Meredith, 2000; Murray et al., 2015).\u003c/p\u003e\n\u003cp\u003eThere have been cross-temporal findings that suggest negative changes in the mental health of today\u0026rsquo;s youth, especially in adolescents and young adults, compared to previous generations: loneliness (Buecker et al., 2021), attention/working memory: (Graves et al., 2021; Wongupparaj et al., 2017), emotional intelligence: (Khan et al., 2021), depression: (Twenge, 2020), resilience: (Zhao et al., 2022). Yet, other studies highlight positive trends. For example, children\u0026rsquo;s self-control, specifically the ability to delay gratification, has improved globally from the 1960s to the 2010s (Protzko, 2020). In certain countries, cross-cohort comparisons reveal improvements (declines) in emotional and behavioral difficulties, rule-breaking, and aggression (Achenbach et al., 2003; Degli Esposti et al., 2023; Langley et al., 2017). In addition to these mixed findings, some indicating improvements and some indicating a decline in the mental health of current generations of youth, there is a general conception that the overall mental health in the current generation of youth is in decline in their qualities relative to earlier generations (Protzko, 2020; Protzko \u0026amp; Schooler, 2019; Russell et al., 2010). Such intuitions need to be definitely grounded in large population-based research.\u003c/p\u003e\n\u003cp\u003eAscriptions of generational decline is termed the \u0026rsquo;kids these days\u0026rsquo; effect (Protzko \u0026amp; Schooler, 2019, 2022, Protzko, 2020). However, such perceptions of decline are affected by memory and perception bias such as projecting our current qualities onto the youth of our past and comparing this skewed and nostalgic view with youth these days, and noticing the limitations of others more easily in something we have already mastered (Protzko \u0026amp; Schooler, 2019). Even experts are not immune to the \u0026lsquo;kids these days\u0026rsquo; effect \u0026nbsp; (Protzko, 2020), underscoring the need for empirical evidence to clarify whether, and in what ways, the mental health of young people has actually changed over time. Thus, instead of relying on a biased memory or biased intuitions, even expert ones, definitive quantitative evidence is required.\u003c/p\u003e\n\u003cp\u003eThis study seeks to answer several key questions: Has the mental health of young people genuinely declined over the past decades? Are there certain emotional and behavioral difficulties that affect today\u0026apos;s young generations less or more? Do these changes vary by age, sex, region, or methodological approach? To address these questions, we investigated changes in subclinical levels of emotional and behavioral problems among youth over recent decades, and identified particularly vulnerable subgroups. Understanding the scale and nature of these changes in an objective way is essential for uncovering the drivers of secular trends and for designing effective, targeted interventions. These issues also hold widespread public interest, given the perception that socio-cultural and environmental shifts in recent decades may have adversely impacted young people\u0026rsquo;s mental well-being. This review extends previous systematic global research in three key ways: (a) by focusing on subclinical rather than clinical-level problems (Piao et al., 2022); (b) by incorporating data collected after 2010 (Bor et al., 2014; Collishaw, 2015); and (c) by employing cross-temporal meta-analysis, a powerful method for examining changes in psychological variables over time using large-scale, globally representative data in the absence of longitudinal datasets (Buecker et al., 2021). In the sections that follow, we present current evidence on the roles of age, sex, and cultural context in mean-level emotional problems, and review prior research on secular trends.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMean-Level Emotional and Behavioral Problems Among Young People\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe mean-level of emotional and behavioral problems is an important indicator of mental health in the youth population, with a higher mean-level of problems indicating worse mental health (Ford \u0026amp; Parker, 2016). Emotional and behavioral difficulties are typically distinguished into internalizing and externalizing problems (Holland et al., 2017). Externalizing problems are related to conflict with others (e.g., rule-breaking or deviant behavior, aggression, also known as conduct problems), while internalizing problems reflect inner distress (e.g., anxiety, depression, psychosomatic symptoms or withdrawal, also known as emotional problems) (Holland et al., 2017). Besides externalizing and internalizing problems, youth commonly exhibit other problems, such as attention, thought, or social problems (Achenbach, 2001).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGenerally, there are age, sex, and cultural differences in mean-level emotional and behavioral problems but also according to the informant. Internalizing problems become more prominent with age and are more common for girls, while externalizing problems become less prominent with age and are more common for boys (C.-Y. Chen et al., 2008; Gutman \u0026amp; Codiroli McMaster, 2020; L. Rescorla et al., 2007; Shaikh \u0026amp; Shinde, 2018). Studies show that when rating themselves, children and adolescents typically report more problems relative to assessments by parents or teachers, and parents report more problems than teachers (except for externalizing problems) (Achenbach et al., 2002; Huang, 2017; Tick et al., 2007; van der Ende et al., 2012). Regarding intercultural differences, although there have been cross-society differences reported between mean-level emotional and behavioral problems, variance was considerably greater within each society than between societies (L. Rescorla et al., 2007; L. A. Rescorla et al., 2019). Externalizing problems, especially aggression have been shown to be the least variant across cultures, while thought problems seem to be the most variant (Ivanova, Achenbach, et al., 2007; Ivanova, Dobrean, et al., 2007; L. A. Rescorla et al., 2007).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe longest time and worldwide used measurement instrument of mean-level emotional and behavioral problems that has been translated into 80 languages are the rating scales of the Achenbach System of Empirically Based Assessment (ASEBA) consisting of the Child Behavior Checklist (CBCL) rated by the parent, the Teacher\u0026rsquo;s Report Form (TRF), and the Youth Self-Report (YSR) (Achenbach, 1991c, 1991b, 1991a). Along with the ASEBA rating scales, the Strengths and Difficulties Questionnaire (SDQ) is also a widely used instrument to measure mean-level emotional and behavioral difficulties (Goodman, 1997) However, the ASEBA battery has been used for longer, has more items and captures more psychological problems from more informants than the SDQ (e.g., the ASEBA includes self-report of youth as well). Both instruments identify children with subthreshold and threshold mental health disorders by cut-off scores based on validity measures of population-based samples (Smedje et al., 1999) Threshold or clinical-level emotional and behavioral problems are more commonly measured by diagnostic interviews with parents or children, for instance according to the DSM criteria by the American Psychological Association (APA). However, substantial changes have been made over the past decades in the diagnostic criteria between versions of the DSM. This makes it more difficult to compare the prevalence of clinical-level mental-health problems of youth from different decades (Collishaw, 2015). In the following section we will review findings about the secular changes in prevalence rates of clinical-level mental health disorders, as well as changes in subthreshold difficulties.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTemporal Changes in Emotional and Behavioral Problems of Youth\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTemporal changes in psychopathology, defined as population-level fluctuations in the prevalence or expression of psychological symptoms over time, are more than descriptive trends (Armitage et al., 2024; Ford, 2008). Secular changes challenge prevailing theories about the origins and course of mental illness. Traditional models of psychopathology, particularly those emphasizing genetic etiology, have sometimes assumed a degree of stability across time and context. However, notable shifts in prevalence within a single generation imply that environmental and psychosocial factors may also play a substantial role (Borg et al., 2025; Fombonne, 1998; Rutter \u0026amp; Smith, 1995). If certain emotional or behavioral problems are increasing among youth, this suggests either that new risk factors have emerged or that existing protective factors are no longer as effective (Fine et al., 2022; Zoellner et al, 2024). In either case, temporal trends compel a re-evaluation of longstanding assumptions about the relative roles of genes and environment in the development of mental illness.\u003c/p\u003e\n\u003cp\u003eRecent advances in psychiatric genetics, including large-scale genome-wide association studies (GWAS) by the Psychiatric Genomics Consortium (Sullivan et al., 2018), have highlighted the heritability of various psychiatric disorders, such as major depressive disorder (MDD). Yet these findings also underscore the complexity of gene\u0026ndash;environment interplay. Models of gene\u0026ndash;environment interaction and differential susceptibility (e.g., Belsky \u0026amp; Pluess, 2009) suggest that genetic predispositions are not deterministic, but instead confer varying degrees of sensitivity to environmental contexts. As the environments inhabited by children and adolescents have changed, due to shifts in technology use, educational pressures, family dynamics, or socioeconomic stressors, the developmental expression of underlying vulnerabilities also might have changed. Temporal change, in this sense, reflects not just epidemiological drift but evolving developmental pathways shaped by historical and cultural context.\u003c/p\u003e\n\u003cp\u003eFrom a public health perspective, understanding these temporal patterns is essential for forecasting needs, allocating resources, and evaluating the effectiveness of mental health interventions. In order to plan and deliver effective mental health services, it is essential to know how many children are experiencing symptoms, what kinds of problems are most common, and whether these patterns are shifting over time (Ford, 2008). If the prevalence of certain difficulties is increasing, or if rates are stable despite the proliferation of intervention programs, this raises critical questions about the suitability and efficacy of existing approaches. It is possible that current interventions, developed in earlier decades, may not adequately address the challenges facing today\u0026rsquo;s youth. Evidence-based practices may need to be updated or re-contextualized to remain effective for contemporary cohorts.\u003c/p\u003e\n\u003cp\u003eTemporal change also has implications for how clinical psychology conceptualizes and measures psychopathology. The dominant taxonomic systems, such as the \u003cem\u003eDiagnostic and Statistical Manual of Mental Disorders\u003c/em\u003e (DSM) and the \u003cem\u003eInternational Classification of Diseases\u003c/em\u003e (ICD), use categorical models that define mental disorders based on symptom thresholds. However, these thresholds often exclude individuals with subclinical symptoms who nonetheless experience significant distress or impairment. Emerging dimensional models, such as the Hierarchical Taxonomy of Psychopathology (HiTOP; Kotov et al., 2017), address these limitations by conceptualizing psychopathology as a spectrum. These models allow researchers to capture gradations of severity, from mild to severe, and are particularly well-suited for detecting secular trends. For instance, dimensional assessments can reveal whether subthreshold symptoms are increasing over time, that is an important finding that may be masked by categorical diagnostic approaches.\u003c/p\u003e\n\u003cp\u003eMoreover, secular trends differ by country, type of disorder, and developmental period, which adds additional complexity to etiological theories. Cross-national differences may reflect a range of methodological, cultural, and policy-related factors, but they also suggest that the social environment plays a powerful role in shaping mental health outcomes (Cosma et al., 2020; Fombonne, 1998). If rates of a given disorder rise in one context but fall or remain stable in another, this variability demands careful investigation into context-specific risk factors. Such trends force researchers to consider the malleability of youth behavior problems and whether some of these issues are more temporally and culturally sensitive than previously assumed (Zhao et al., 2021). The assumption that emotional and behavioral problems are inherently stable may obscure their dynamic responsiveness to shifting environmental and sociocultural forces.\u003c/p\u003e\n\u003cp\u003eIn sum, the study of temporal changes in youth psychopathology is not merely a historical or descriptive endeavor. It provides critical insights into the developmental origins of mental illness, the relevance and responsiveness of current clinical practices, and the conceptual frameworks used to define psychological disorders. As prevalence rates, symptom profiles, and risk factors evolve over time, so too must the tools and theories used by clinical scientists and practitioners. Ultimately, a deeper understanding of these changes can inform more accurate models of psychopathology, more responsive mental health services, and more effective prevention and intervention strategies for future generations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePrevious Studies on Secular Changes in Clinical-Level Problems\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn 2019 8.8% of children and adolescents were diagnosed with mental health disorders globally (Piao et al., 2022). Within the subtypes of various mental disorders, anxiety disorder accounted for the highest prevalence, followed by developmental intellectual disability and attention-deficit/hyperactivity disorder. The Global Disease Burden study revealed a slight decrease (by 1.3%) in the prevalence rates of mental disorders from 1990 to 2019 in youth aged 0\u0026ndash;19 years (Piao et al., 2022). In these three decades, the highest prevalence rate among mental disorders changed from developmental intellectual disability to anxiety disorders. The most significant increases in the prevalence of different mental disorders were observed for depression (an increase of 10.9% from 1990), conduct disorder (an increase of 8.2% from 1990), and anxiety disorder (an increase of 1.6% from 1990), while the most significant decreases were reported for developmental intellectual disability and attention-deficit/hyperactivity disorder.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSecular Changes in Subclinical Problems\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere are no recent global findings about the cross-temporal changes in subclinical-level emotional and behavioral problems of youth but only country-specific studies (see Table 1). Certainly, there are advantages of national epidemiological cross-cohort comparisons, longitudinal studies, and cross-temporal meta-analysis as these can directly influence the policy making of a country, however, there are a lot of countries where no such study exists (see Table 1). Those countries can benefit even more from global results. There were only two systematic studies that examined global time trends in emotional and behavioral problems: one that showed no change in externalizing and internalizing problems between 1990 and 2010 for youth aged 0-18 years, but an increase in internalizing problems for 12-18 year old girls (Bor et al., 2014); the other showed an increase in emotional problems for all age groups, and no change in hyperactivity or conduct problems (Collishaw, 2015). These global results need to be updated by including data after 2010, improved with the empirical method of a cross-temporal meta-analysis and by investigating a more fine-grained picture on different emotional and behavioral problems.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs Table 1 shows, country-specific studies on secular changes in emotional and behavioral problems are more common, especially in certain countries such as the UK, the Netherlands, the USA, Brazil or China. The most robust evidence is grouped around convergent evidence across multiple informants but these studies are limited in number (3 from the UK, 1 from the US, and 1 from the Netherlands) (see Table 1). In the UK the following trends were detected: between 1974-1999 increased emotional and conduct problems and no change in hyperactivity according to parent- and self-report (Collishaw et al., 2004); between 1986-2006 increased emotional problems reported by parents and teenage girls (Collishaw et al., 2010); between 1999-2008 total problems and conduct problems reducing in both sexes according to parents and teachers (Sellers et al., 2015). However, it is important to note that teachers\u0026rsquo; and parents\u0026rsquo; reports diverged regarding some problems, especially in emotional problems and hyperactivity (Maughan et al., 2008; Sellers et al., 2015). In the Netherlands, parents, teachers and children all reported no change in aggression, social problems and thought problems between 1983-2003 (Tick et al., 2007) but reports were divergent in changes in total, internalizing and externalizing problems. In the USA between 1976-1999 both parents and teachers reported an increase in total problems until 1989, and then a decrease until 1999 (Achenbach et al., 2003).\u003c/p\u003e\n\u003cp\u003eFurther strong evidence of changes in the mental health of young people comes from cross-sectional studies with annual measurements over long periods of time, such as the Health Behavior in School-aged Children study (HBSC). In Scotland and Sweden HBSC studies reported an increase in self-reported somatic complaints between 1998-2018 (Inchley et al., 2023) and in the number of students reporting frequent complaints (H\u0026ouml;gberg et al., 2023). However, only some somatic and mood symptoms are studied in the HBSC, not a diverse fine-categorized set of emotional and behavioral problems.\u003c/p\u003e\n\u003cp\u003eIn summary, previous evidence on secular changes in subclinical emotional and behavior problems show mixed results and is limited in the following ways: (a) there is a need for a more fine-grained classification of emotional and behavioral problems to study the time trends more specifically; (b) evidence across multiple informants is rare, which gathers the most robust evidence (e.g., there is a very limited number of previous studies on secular changes in the mental health of teens that is not self-reported); (c) there are no empirical studies with a broader framework in time and location. The current review overcomes these limitations by: (a-b) applying a more fine-grained classification system for emotional and behavioral problems by using the ASEBA battery with multiple informant (parents, teachers, and self reports); (c) studying a longer time period than previous studies, (over four decades) and reporting on global changes. Previous cross-cohort and cross-temporal studies showed that time trends of changes in emotional and behavioral problems may also differ by age, sex, and geographical location, thus these moderators were also taken into account when exploring time trends.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u0026nbsp;\u003c/strong\u003e\u003cem\u003eSummary of Previous Studies About Secular Changes Across Time in Subclinical Emotional and Behavioral Problems\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"595\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFirst author \u0026amp; publication year\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eStudy type\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eYear of data\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCountry\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTrend\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eInformant\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\" style=\"width: 595px;\"\u003e\n \u003cp\u003e\u003cem\u003eEurope\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eSourander, 2004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1989-1999\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eFinland\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; conduct and total problem for boys\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e8 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eSellers, 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (3 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1999-2008\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUK\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; \u0026nbsp;total, conduct, and emotional problems, \u0026harr; hyperactivity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e7 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; \u0026nbsp;total and conduct problems, \u0026darr; hyperactivity for boys,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026harr; emotional problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eteacher\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eTick, 2007\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1989-2003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eNetherlands\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; \u0026nbsp;total problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2-3 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eH\u0026ouml;lling, 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2003-2012\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eGermany\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; conduct problems,\u0026harr; hyperactivity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e3-13 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems,\u0026harr; hyperactivity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e14-17 years\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eSantalahti, 2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1990-2000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eFinland\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; somatic problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e8-9 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eLangley 2017\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2005-2015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eWales\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; total problems, hyperactivity, aggression and rule-breaking for boys,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026harr; for girls\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e4-7 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; total problems, hyperactivity, aggression and rule-breaking for girls,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026harr; for boys\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e7-12 years\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eCollishaw (2004, 2007)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (3 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1974-1999\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUK\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; conduct problems, emotional problems, \u0026harr; hyperactivity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e15-16 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eCollishaw (2010, 2012)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1986-2006\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUK\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e16-17 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems for girls, \u0026harr; for boys\u003cbr\u003e\u003c!--[if !supportLineBreakNewLine]--\u003e\u003cbr\u003e\u003c!--[endif]--\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eMaughan, 2008\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1999-2004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUK\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; total problems, conduct problems, hyperactivity, \u0026harr; emotional problems\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e5-15 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026harr; total problems, conduct problems, hyperactivity, \u0026uarr; emotional problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eteacher\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eTick, 2007\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1983-2003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eNetherlands\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; total, internalizing problems, \u0026harr; aggression, thought and social problems\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e6-16 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026harr; total, externalizing, internalizing problems, aggression, thought or social problems, \u0026uarr; attention problems increase\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eteacher\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; total problems for boys, \u0026uarr; internalizing for girls\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eArmitage 2023\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2013-2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUK\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems with an earlier onset of problems\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e11-16 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003evon Soest, 2014\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (3 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1992-2010\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eNorway\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; depression for boys from 1992 to 2002, \u0026darr; conduct problems for boys from 2002 to 2010\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e16-17 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eTorikka, 2014\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eLongitudinal study (10 assessments)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2000-2011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eFinland\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026harr; in mild or moderate depression, \u0026uarr; in severe depression for both sexes\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e14-16 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eSweeting (2009, 2010)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (3 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1987-2006\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUK\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; depression\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e15 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eSigfusdottir, 2008\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (4 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1997-2006\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eIceland\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; \u0026nbsp; \u0026nbsp; \u0026nbsp; depression \u0026nbsp;for girls, anxiety for both sexes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e14-15 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eWangby, 2005\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1970-1996\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eSweden\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026harr; emotional problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e15 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eInchley 2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (6 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1998-2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eScotland\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; feeling low, feeling nervous, sleep difficulties and backache\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e11-15 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eH\u0026ouml;gber, 2022\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (6 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1998-2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eSweden\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; in the proportion of students with frequent somatic complaints\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e11-15 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eAnthony, 2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (3 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2013-2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eWales\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e11-16 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\" style=\"width: 595px;\"\u003e\n \u003cp\u003e\u003cem\u003eNorth \u0026amp; South America\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eMatijasevich 2014\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1993-2004\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eBrazil\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; total problems, aggression and attention problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e4 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eDegli Esposti, 2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (3 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1997-2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eBrazil\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; total problems 1997-2010,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026darr; aggression and rule-breaking 2010 -2020\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e4 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eAchenbach, 2003\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1976-1999\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUSA\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; total problems 1976-1989, \u0026darr; total problems 1990-1999\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e7-16 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eteacher\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eMason, 2023\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1997-2017\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; somatic problems and anxiety,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026harr; social problems, depression, and rule-breaking\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e5-18 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eteacher\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eKeyes, 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (28 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1991-2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026darr; depression 1991-2011,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026uarr; 2011-2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e13-18 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\" style=\"width: 595px;\"\u003e\n \u003cp\u003e\u003cem\u003eAsia\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eLin, 2007\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1993-2003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eChina\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems, \u0026uarr; externalizing problems for girls\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e6-14 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eSu, 2020\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-temporal meta-analysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1989-2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eChina\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; depression for boys,\u0026nbsp;\u003cbr\u003e\u0026nbsp;\u0026harr; for girls\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e12-18 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eXin, 2010\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-temporal meta-analysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1992-2005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eChina\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; anxiety\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e12-17 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eDu, 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-temporal meta-analysis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2010-2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eChina\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026harr; depression 2010-2020,\u0026nbsp;\u003cbr\u003e\u0026nbsp;\u0026uarr; 2021-2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e10-19 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\" style=\"width: 595px;\"\u003e\n \u003cp\u003e\u003cem\u003eAustralia\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eFleming, 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eCross-cohort comparison (2 cohorts)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e2007-2012\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eNew Zealand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; depression, emotional problems, hyperactivity, \u0026darr; conduct problems\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e10-17 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eself\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"7\" valign=\"top\" style=\"width: 595px;\"\u003e\n \u003cp\u003e\u003cem\u003eGlobal\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eBor 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eSystematic review\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1990-2010\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003emore countries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026harr; externalizing and internalizing problems, \u0026uarr; internalizing problems for girls above 12 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0-18 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent, teacher, self\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 78px;\"\u003e\n \u003cp\u003eCollishaw 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eSystematic review\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e1970-2012\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003emore countries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u0026uarr; emotional problems, \u0026harr; \u0026nbsp;conduct problems and hyperactivity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e0-18 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eparent, teacher, self\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u0026darr; represents a decrease, \u0026uarr; represents an increase, and \u0026harr; represents no change\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eEmotional and Behavioral Problem Measure\u003c/h2\u003e\u003cp\u003eWe used the Achenbach System of Empirically Based Assessment (ASEBA), consisting of the Child Behavior Checklist (CBCL) rated by the parent, the Teacher\u0026rsquo;s Report Form (TRF), and the Youth Self-Report (YSR) (Achenbach, 1991b, 1991c, 1991a, 2001; Achenbach \u0026amp; Edelbrock, 1986, 1987, 1983; Achenbach \u0026amp; Rescorla, 2000), to measure cross-temporal changes in emotional and behavioral problems. All informant versions use a 3-point Likert scale (0 - not true, 1 - sometimes true, 2 - very or often true) for each individual item, with more points indicating more problems. For the eight main problems with behavioral and emotional examples see Table\u0026nbsp;2. Along with the cross-cultural comparability of the checklist, there is also evidence for the cross-temporal comparability. The checklist exists for 40 years, though subtle changes have been made to the items, from the 120 items of the 1980s, 1990s, and 2000s versions of the CBCL, 114 remained common allowing comparisons over time (Achenbach et al., 2003). Importantly, rank ordering of these item scores produces a high stability (\u003cem\u003eQ\u003c/em\u003e correlation .94-.98) over time. Additionally, for the subscales among versions of the checklist high and very high correlations have been reported based on the comparisons of the Achenbach normative samples in the U.S. from three different decades (Achenbach, 1991b, 1991c, 1991a, 2001; Achenbach \u0026amp; Rescorla, 2000). Findings from the cross-cohort comparison of the CBCL, TRF, and YSR supported the temporal measurement invariance of the rating scale, meaning that the same problems were being measured across time (Achenbach et al., 2002; L. A. Rescorla et al., 2011). In sum, despite some cross-temporal and cross-cultural variation, the evidence shows that the ASEBA rating scales have an empirically based methodology that is robust across diverse cultures and comparable across time, thus making it possible to use in cross-cohort comparisons or cross-temporal meta-analysis (Crijnen et al., 1999; Ivanova et al., 2019; Tick et al., 2007).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e\u003cem\u003eSubscales of the ASEBA Battery with Examples of Items\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSubscales of the CBCL, TRF, and YSR\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eExamples of Items\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eanxious-\u003c/p\u003e\u003cp\u003edepressed\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003efears school, fears certain situations or places, worries a lot, feels worthless, feeling hurt, feels pressure to be perfect, nervous or tense\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eattention problems\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ecan\u0026rsquo;t pay attention for long, restless, hyperactive, impulsive or acts without thinking, talks too much, easily distracted, daydreams, fails to finish, poor school work\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eaggression\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eargues a lot, mean, destroy things, disobedient, gets in many fights, threatens or attacks others, screams, irritable, sudden mood changes, suspicious, temper tantrums, selfish\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003edeviant (or rule-breaking) behavior\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003euse alcohol/tobacco/drugs, hangs around with other who get in trouble, lacks of guilt, breaks rules, lies, cheats, steals, swears, runs away, sets fire, skips school, vandalism\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003esomatic complaints\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003efeels dizzy, trouble sleeping (i.e., nightmares), tired, physical problems without a medical cause (e.g., headache, stomachache, vomiting, rashes or skin problems, eye problems), not eating\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003esocial problems\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003efeels lonely, not get along with other kids, easily jealous, teased a lot, not liked by other kids, speech problems, prefer being with younger kids\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ethought problems\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ecan\u0026rsquo;t get mind off certain thought, hears and sees things that aren\u0026rsquo;t there, repeat certain acts compulsively, sleep less than most kids, strange behavior or ideas\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ewithdrawn-\u003c/p\u003e\u003cp\u003edepressed\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003espends time rather alone, overtired without a good reason, secretive, rather not talk, acts shy, feeling unhappy, underactive, avoids eye contact, little interest in things around\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eLiterature Search\u003c/h3\u003e\n\u003cp\u003eA systematic search was conducted in five databases (PubMed, Web of Science, Scopus, EBSCO, Google Scholar) for journal articles in English up until February 2022. The following search string was used: (\u0026ldquo;CBCL\u0026rdquo; OR \u0026ldquo;Child Behavior Checklist\u0026rdquo; OR \u0026ldquo;TRF\u0026rdquo; OR \u0026ldquo;Teacher Report Form\u0026rdquo; OR \u0026ldquo;YSR\u0026rdquo; OR \u0026ldquo;Youth Self-Report\u0026rdquo;) AND (representative OR population-based). The search string was screened in titles and abstracts in four databases, except for Google Scholar where there was no such option, so in that case the full texts of articles were screened with the search string. Moreover, using the snowball method (Sayers, 2008), reference lists of relevant meta-analyses, review articles, and included studies were screened to identify further studies for inclusion.\u003c/p\u003e\n\u003ch3\u003eInclusion and Exclusion of Studies\u003c/h3\u003e\n\u003cp\u003eCriteria for studies to be included in this cross-temporal meta-analysis were the following:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eTo explore the changes in emotional and behavioral problems within the last decades, we chose a universally well-known and widely used standardized measurement instrument of such problems among youth, the Child Behavior Checklist (CBCL)\u003csup\u003e14\u003c/sup\u003e. Those studies were included in the meta-analysis which used the parent-reported Child Behavior Checklist (CBCL), the Teacher\u0026rsquo;s Report Form (TRF), or the Youth Self-Report (YSR), which are different versions of the CBCL designed to be filled in by teachers and youth themselves.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eOnly samples up until the age of 18 years were included. It should be noted that we extended the pre-registered age limit of 14 years in order to cover adolescence as a whole. There was no minimum age limit for the samples, however, the parent-reported CBCL can be used from around 1 year of age.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eStudy samples had to be population-based, meaning that the participants were taken from the general population sharing common characteristics with a probability sampling method such as simple random sampling from the population, systematic sampling, stratified sampling, and clustered sampling, or the mix of these methods.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe last inclusion criterion was that studies had to report the raw mean (\u003cem\u003eM\u003c/em\u003e) and standard deviation (\u003cem\u003eSD\u003c/em\u003e) for one or more subscales or the Total Problems score of the CBCL, TRF, or YSR. In cases when the \u003cem\u003eM\u003c/em\u003e or \u003cem\u003eSD\u003c/em\u003e was missing from the article, the first author was contacted through email to provide this data.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eStudies were excluded in cases when: (1) the items of the subscales were mixed with items from other questionnaires e.g., (Vergunst et al., 2019); (2) the data was incomplete or inappropriate for the analysis due to a missing \u003cem\u003eM\u003c/em\u003e or \u003cem\u003eSD\u003c/em\u003e e.g., (Ellersgaard et al., 2018); or only z-scores e.g., (Bohlin \u0026amp; Janols, 2004), t-scores e.g., (Kim et al., 2021), prevalence rates were reported e.g.,(Dudani et al., 2010); (3) it was a twin study e.g.,(Whipp et al., 2021); or (4) the sample was not representative of a general population e.g., (Shooshtari et al., 2014).\u003c/p\u003e\u003cp\u003eIn those cases, when behavioral data were reported for a population-based sample, but the sample was divided into subgroups e.g., picky eaters and non-picky eaters (Machado et al., 2016), means and \u003cem\u003eSD\u003c/em\u003es for all groups were coded and the weighted average was taken. There were cases when large cohort longitudinal data was reported in multiple studies (e.g., Generation R). These cases were reviewed by coders to avoid including the data of the same samples twice in the analysis and the most complete data was chosen. From longitudinal cohorts, a single time point was randomly chosen for each of the age group categories. Studies with year of data collection during or after the COVID-19 pandemic (\u003cem\u003ek\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3) were excluded from the analysis due to their low number. Lastly, there were only a few studies reporting on the Diagnostic and Statistical Manual of Mental Disorders (DSM) oriented subscales of the CBCL, TRF, or YSR, thus we decided to exclude studies which only reported on these subscales (El Marroun et al., 2014; Mossin et al., 2017; Oerbeck et al., 2020; Otterman et al., 2019; Sondeijker et al., 2007; Zerwas et al., 2014).\u003c/p\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003eCoding of Studies\u003c/h2\u003e\u003cp\u003eEach included study was coded in a standardized coding scheme in regards to (1) emotional and behavioral problems data: the number of participants (n),mean (\u003cem\u003eM\u003c/em\u003e) and standard deviation (\u003cem\u003eSD\u003c/em\u003e) of raw scores on all available CBCL, TRF, or YSR subscales and total problems score, (2) outcome information: informant, number of items on the subscale or total score, maximum possible point on the subscale or total score, Cronbach\u0026rsquo;s alpha coefficients regarding reliability, version of the questionnaire (1981, 1991 or 2001 versions), (3) characteristics of the sample: country and continent of data collection, mean and range of the age of the sample, birth year of the sample which was also categorized into birth cohorts, sex distribution, sampling frame, response rate (the percentage of approached participants who were willing to participate), the ratio of marginalized ethnicities in the sample and (4) the year of data collection. In those cases when the year of data collection was not reported (and could not be retrieved from another study on the same cohort), we subtracted 2 years from the publication year (for a similar procedure see (Buecker et al., 2021; Khan et al., 2021; Protzko, 2020)). In cases when the mean age of the sample was not reported, the two ends of the age range were averaged. When means and \u003cem\u003eSD\u003c/em\u003es were reported separately for boys and girls and for the mixed sex sample as well, we coded the separately reported means and \u003cem\u003eSD\u003c/em\u003es in order to allow for analyses separately for the two sexes. In all other analyses, the combined mean of the two sexes was used. This was true for different age groups as well. When the \u003cem\u003eM\u003c/em\u003e or \u003cem\u003eSD\u003c/em\u003e was not reported in a study, and those were also not found in other studies reporting on the same cohort, the corresponding authors were contacted to provide the missing data. The selection and coding were done by independent pairs from the two lead authors and a trained group of research assistants. Disagreements in the selection and coding of the studies were resolved by the first author.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eData Preparation\u003c/h2\u003e\u003cp\u003eFirstly, as the CBCL, TRF, and YSR have old and new versions (from 1981, 1991 and 2001) with different maximum points, we calculated the percentage of maximum possible (POMP) scores that obtain comparable scores across studies (Buecker et al., 2021). The maximum possible points on the (sub)scales were coded based on the information written in the individual studies, or if not reported in the study then it was coded based on the referred manual. The POMP scores were calculated with linear transformation of the raw scores (\u003cem\u003eM\u003c/em\u003e and \u003cem\u003eSD\u003c/em\u003e). The following steps were used for the \u003cem\u003eM\u003c/em\u003e: (1) subtracting the minimum possible score from the raw mean, (2) subtracting the minimum possible score from the maximum possible score, (3) dividing these previously calculated two scores, (4) multiplying the received quotient by 100. POMP \u003cem\u003eSDs\u003c/em\u003e were calculated in a similar manner: (1) subtracting the minimum possible score from the maximum possible score, (2) dividing the raw \u003cem\u003eSD\u003c/em\u003e with the previously calculated score, (3) multiplying the received quotient by 100. Higher POMP scores and higher raw means both indicate more emotional and/or behavioral problems.\u003c/p\u003e\u003cp\u003eSecondly, as most emotional and behavioral problems on average show age and sex-specific patterns, age and sex were used for categorization to provide more fine-grained analyses of the cross-temporal changes. Based on their mean age, samples were categorized into one of the three age groups (i.e., early childhood from 1 to 6 years, middle childhood from 7 to 14 years, and teens from 15 to 18 years). Additionally, a more fine-grained age grouping was also used for a sensitivity analysis of age groups (i.e., early childhood was divided into toddlers until 2 years and preschoolers from 3 to 6 years, and middle childhood into primary school-age from 7 to 10 years and middle school-age from 11 to 14 years, and teens from 15 to 18 years).\u003c/p\u003e\u003cp\u003eThirdly, as previous evidence on changes in emotional and behavioral problems over time show some cross-national differences among youth, we categorized the included population-based studies on a regional level, based on continents. However, as the total number of included studies for Australian, and African samples were too small to estimate meta-regression coefficients, these continents were not included in the subgroup analysis of continents.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eMeta-Analytic Procedure\u003c/h2\u003e\u003cp\u003eStatistical analyses were carried out using the packages `meta` (Schwarzer, 2007) and `metafor' (Viechtebauer, 2021) in the R statistical software (R Core Team, 2021). The statistical analyses followed guidelines from a book about meta-analysis (Harrer et al., 2021). A \u003cem\u003ep\u003c/em\u003e-value of less than 0.050 was considered significant. Note, however, that the number of performed hypothesis tests was quite large; hence, false significant results can be present in the study. The size of the effect and the corresponding confidence intervals are most informative. Regarding \u003cem\u003ep\u003c/em\u003e-values, in case of a significant result (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.050), the smaller the \u003cem\u003ep\u003c/em\u003e-value, the more unlikely that the significant result is false.\u003c/p\u003e\u003cp\u003eWe analyzed the CBCL, TRF and YSR problem scale mean values separately. All analyses detailed below are random-effect analyses using restricted maximum likelihood estimators. To analyze the temporal changes in the score means, we used meta-regression analyses. Importantly, there is no effect size computation in a cross-temporal meta-analysis, instead, the change in mean scores on psychological measures is examined among similar-aged groups in different time points of the past (Gonthier \u0026amp; Gr\u0026eacute;goire, 2022). The coefficient of the predictor year of data collection has a clear interpretation: it shows how much the corresponding score (in the corresponding stratum) changes on average within one year. We visualized the results on regression plots showing the fitted regression line along with the study results. These scatterplots made it possible to check graphically whether the linear usage of the year is adequate or not. Heterogeneity was assessed by calculating \u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e statistics and by reporting \u003cem\u003eTau\u003c/em\u003e, the estimated standard deviation of the random effect term. The fitted random effect meta-model estimates the average true effects of each data year. The random effect term, and hence its estimated standard deviation denoted by \u003cem\u003eTau\u003c/em\u003e, describes the additional random fluctuation of the true effects of the studies. According to the fitted model, ignoring that \u003cem\u003eTau\u003c/em\u003e is just an estimate of the true \u003cem\u003eSD\u003c/em\u003e of the random effects, it is roughly true that 95% of the true effects of the studies deviate less than two times Tau from the year-specific average provided by the regression.\u003c/p\u003e\u003cp\u003eTo assess whether the temporal changes of the scores depended on other moderators (i.e., age group, sex, continent, response rate), we applied stratified exploratory analyses. The reason why we chose stratified analysis instead of using age as a continuous moderator is that in our sample age was a broad category including children from ages 1 to 18 years from very different developmental stages. As far as we know, this can cause aggregation bias in meta-analysis, and analyses in stratified subgroups are advisable (Harrer et al., 2021). Importantly, we chose not to correct for multiple tests is due to the explorative nature of the current study as the number of performed statistical tests is enormous. It is not clear to which subsets we should apply corrections. In this situation, in our opinion, it is a much clearer approach to report the original p-value.\u003c/p\u003e\u003cp\u003eIf the number of studies was less than 5 in a stratum, we did not perform the meta-regression. In the case of the univariate sex analyses, to take into account that the random effects of the boys' and girls' results within a study are correlated, we fitted a two-dimensional random-effect model (Olkin \u0026amp; Gleser, 2009).\u003c/p\u003e\u003cp\u003eWe performed influential analysis using the default setting of the influential() function of the metafor R package (Viechtebauer, 2021). It calculates several influential statistics and automatically marks studies as influential if one of the DFFIT, Cook's distance, hat value, or DFBETA statistics indicates a significant influence. We performed a sensitivity analysis by simultaneously leaving out all the studies marked as influential (see supplementary Table S5-S7).\u003c/p\u003e\u003cp\u003eAdditionally, many sensitivity analyses were performed. Firstly, in multivariate meta-regression models response rate was used as a control variable, in order to identify if the main effect of the year of data collection deviated from the univariate results when controlling for response rate (the percentage of approached participants who were willing to participate). We considered response rate an important control variable because lower response rates can suggest a response bias (i.e., disadvantaged families are usually harder to reach) and potential issues with representativeness. In addition to conducting the analyses regarding the three age groups (early childhood, middle childhood, teens) we repeated these analyses for a finer categorization with five categories (toddlers, preschoolers, elementary school aged children, middle school aged children, teens). However, as there were not much deviations in the results and the analyses with three categories have more statistical power, results regarding the five categories are only reported in the Supplemental Materials (see Table S2). In order to assess potential differences due to the three different versions of the CBCL, we performed supplementary analyses excluding the version from 1981, as there were substantially fewer studies using the earliest version of the CBCL. Further, analyses were also performed to test the differences between the 1991 and the 2001 version of the CBCL, TRF, and YSR by (see Table S3), and the cross-temporal changes only with the 2001 version of the CBCL, TRF, and YSR was also supplementary tested (see Table S8). These separate analyses also served as a simple non-linearity check, complementing the visual check of the scatterplots.\u003c/p\u003e\u003cp\u003eLastly, in response to reviewer feedback, we conducted simple regressions to assess (1) whether the reliability of the subscales changed over the years and if reliability was related to the means and (2) whether the ratio of marginalized ethnic minorities in the sample was related to the means.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003eTransparency and Openness\u003c/h2\u003e\u003cp\u003eWe adhered to the PRISMA 2020 guidelines for systematic reviews (Page et al., 2021). Data, analysis code, and supplementary analysis plots are available at the repository linked below the data availability statement. Data were modeled using the packages `meta` (Schwarzer, 2007) and `metafor' (Viechtebauer, 2021) in the R statistical software (R Core Team, 2021). This review project was pre-registered at \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e[link removed for masked review]\u003c/span\u003e.\u003c/p\u003e\u003cp\u003eThere were some small deviations from the pre-registration protocol, for instance in the search string, that are disclosed in the supplementary (see Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). Additionally, in October 2023, an updated and expanded systematic search was performed by removing \u0026bdquo;representative or population-based\u0026rdquo; and using \u0026bdquo;epidemiol*\u0026rdquo; and \u0026bdquo;populat*\u0026rdquo; instead in response to reviewer requests. This second systematic search was conducted in all previously searched databases except for Google Scholar. The PRISMA flow diagram shows both systematic search processes, with the first one identifying 100 eligible studies, and the second one with 75 additional studies, resulting in a sum of 175 studies (see Figure A1).\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eDescriptive Statistics\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn total, 175 included studies, with most studies reporting parent-reported externalizing problems for the combined age analysis (with 1-18 year olds; \u003cem\u003ek\u003c/em\u003e = 100), followed by internalizing (\u003cem\u003ek\u003c/em\u003e = 97), and total problems (\u003cem\u003ek\u003c/em\u003e = 74). There were34 studies for self- and 24 for teacher-report of externalizing problems, with a similar number of studies for internalizing and total problems. Earliest data was from 1981 and latest from 2021. The lowest number of studies were from the 1980s (\u003cem\u003ek\u003c/em\u003e = 10), then the 1990s (\u003cem\u003ek\u003c/em\u003e = 48), with the most from the 2000s (\u003cem\u003ek\u0026nbsp;\u003c/em\u003e= 65). The majority of the studies included samples from European countries (\u003cem\u003ek\u003c/em\u003e = 91), followed by North and South American (\u003cem\u003ek\u003c/em\u003e = 41), Asian (\u003cem\u003ek\u003c/em\u003e = 30), Australian (\u003cem\u003ek\u003c/em\u003e = 7), and African (\u003cem\u003ek\u003c/em\u003e = 3) countries. The countries with the most data collection points were the Netherlands in Europe, the U.S. in North and South America, and China in Asia (see Table S4 for the year of data collection points by country). The average age of the samples was 10.87 years (\u003cem\u003eSD\u003c/em\u003e = 4.12), ranging from 1 to 18 years.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eReliability of the Subscales\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCronbach alpha for the subscales and/or the total score was reported in 76/175 primary studies and ranged between 0.27 and 0.98. Internal reliability did not show any significant changes over the years except for a significant decrease in the reliability of parent-reported attention problems (\u003cem\u003ek\u003c/em\u003e = 16, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.005, \u003cem\u003ep\u003c/em\u003e = .005) and deviant behaviour (\u003cem\u003ek\u003c/em\u003e = 18, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.008, \u003cem\u003ep\u003c/em\u003e = .033) (for scatter plots see the OSF link under the Data Availability statement). Reliability estimates of parent-reported attention problems, in turn, had a significant, negative relationship with the means of parent-reported attention problems with studies reporting better reliability showing smaller scores. This was not the case for deviant behaviour. Thus measurement invariance seems to be problematic in the case of the parent-reported attention problem subscales and it might have affected the results regarding this subscale.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUnivariate Differences in Emotional and Behavioral Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were a few significant differences in mean emotional and behavioral problems within subgroups of continents (Europe, America, Asia) and age groups (early, middle childhood, teens), and several differences of sexes (girls, boys) and response rates revealed by univariate analysis. The significant differences are summarized and written in bold in Table A2-4. The ratio of marginalized ethnic minorities in the samples was reported for almost half (53%) of the studies. The ratio of marginalized ethnic minorities had significant, positive relationships with the amount of aggression reported by teachers, thought problems reported by both parents and self-reports, and total problems reported by parents (for scatter plots see the OSF link under the Data Availability statement). However, the ratio of marginalized ethnicities did only show significant changes in case of self-reported anxiety-depression with a decrease over the years (\u003cem\u003ek\u003c/em\u003e = 11, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= \u0026nbsp; -1.782, \u003cem\u003ep\u003c/em\u003e = .048).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Total Emotional and Behavioral Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable A5 gives an overview and Table A6-A16 gives detailed results from the stratified analysis by informant, age group, sex, and continent, and shows those cases where the analysis was not conducted due to a low number of studies. Importantly, there were many cases where the study number was low, especially for continental results by age groups. Analyses controlling for response rate are also presented in the previously mentioned tables. The results of the sensitivity and supplementary analyses and the models excluding influential cases are shown in the supplemental materials (Table S2-S5). All scatterplots and heterogeneity analysis are shared through the OSF link under the Data Availability statement. The \u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e were substantially high in almost all cases (\u0026lt;90%), heterogeneity (\u003cem\u003eTau\u003c/em\u003e) is reported for the significant analysis.\u003c/p\u003e\n\u003cp\u003eThe univariate meta-regressions showed no change in total emotional and behavioral problems of youth over the last 40 years according to parent reports. When response rate was controlled, parent reported total problems decreased over the last four decades among early childhood samples (\u003cem\u003ek\u003c/em\u003e = 20, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.22, \u003cem\u003ep\u003c/em\u003e = .029, 95%CI[-0.41,-0.03], \u003cem\u003eTau\u003c/em\u003e = 3.19) and among European samples of children in middle childhood (\u003cem\u003ek\u003c/em\u003e = 21, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.09, \u003cem\u003ep\u003c/em\u003e = .047, 95%CI[-0.18,0], \u003cem\u003eTau\u003c/em\u003e = 1.5). Similarly, teacher reports showed no change in total problems of youth overall, however, the sensitivity analysis excluding the study that used the 1980s version, showed a significant decrease over the last 30 years (\u003cem\u003ek\u003c/em\u003e = 22, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.17, 95%CI[-0.32,-0.02], \u003cem\u003ep\u003c/em\u003e = .033). Similarly, a decrease in teacher reported total problems was detected in middle childhood among European samples (\u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.12, \u003cem\u003ep\u003c/em\u003e = .030, 95%CI[-0.22,-0.02], \u003cem\u003eTau\u003c/em\u003e = 0.96), which was similar in magnitude but no longer statistically significant when response rate was included in the model. Thus, according to direct measures from parents and teachers, children have either had fewer or the same number of total problems since the 1980s.\u003c/p\u003e\n\u003cp\u003eMeta-regression analyses of self-reports of total problems of youth showed mixed results. There was a significant increase in total problems overall (\u003cem\u003ek\u003c/em\u003e = 28, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.22, 95%CI[0.02,0.42], \u003cem\u003ep\u003c/em\u003e = .029), however, this effect was substantially reduced and not significant when response rate was controlled for. When analyzing age groups separately, there was no change in self-reported total problems over the last decades among middle childhood samples, yet, when response rate was partialed out it showed a significant decrease with time (\u003cem\u003ek\u003c/em\u003e = 8, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.33, \u003cem\u003ep\u003c/em\u003e = .029, 95%CI[-0.61,-0.05], \u003cem\u003eTau\u003c/em\u003e = 1.49). Among teens, the univariate analysis of self-reports detected a significant increase with year of data collection (\u003cem\u003ek\u003c/em\u003e = 18, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.29, 95%CI[0.01,0.57], \u003cem\u003ep\u003c/em\u003e = .046, \u003cem\u003eTau\u003c/em\u003e = 3.8). This effect was similar in size but no longer significant when response rate was controlled for. In the same vein, when influential cases (\u003cem\u003ek\u003c/em\u003e = 2) were excluded, the effect became non-significant. On the other hand, a significant decrease was found among teenage boys based on self-reports, but only when response rate was controlled for (\u003cem\u003ek\u003c/em\u003e = 11, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.57, \u003cem\u003ep\u003c/em\u003e = .032, 95%CI[-1.08,-0.06], \u003cem\u003eTau\u003c/em\u003e = 2.23).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Externalizing Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were no significant changes in externalizing problems overall. However, we found a significant decrease in middle childhood based on parents\u0026rsquo; (\u003cem\u003ek\u003c/em\u003e = 60, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.21, \u003cem\u003ep\u003c/em\u003e \u0026lt; .001, 95%CI[-0.30,-0.11], \u003cem\u003eTau\u003c/em\u003e = 3.29) over the last 40 years (see Figure 1). The effect was very similar in size when we controlled for response rate. This decrease in middle childhood was confirmed when inspecting parents\u0026rsquo; reports in North and South America (\u003cem\u003ek\u003c/em\u003e = 16, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.21, \u003cem\u003ep\u003c/em\u003e = .030, 95%CI[-0.40,-0.03], \u003cem\u003eTau\u003c/em\u003e = 3.41), which effect was the same in size but no longer significant when response rate was controlled for. The decrease in middle childhood was also confirmed in parent reports in Europe (\u003cem\u003ek\u003c/em\u003e = 30, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.20, \u003cem\u003ep\u003c/em\u003e = .028, 95%CI[-0.38,-0.02], \u003cem\u003eTau\u003c/em\u003e = 3.78), which effect was still significant when response rate was controlled for, however, when we excluded the two studies using the oldest version of the CBCL in a sensitivity analysis, the effect was substantially reduced and no longer significant. Again, the decrease in middle childhood based on parental reports was also confirmed in samples of boys (\u003cem\u003ek\u003c/em\u003e = 29, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.38, \u003cem\u003ep\u003c/em\u003e \u0026lt; .001, 95%CI[-0.59,-0.17], \u003cem\u003eTau\u003c/em\u003e = 3.65) and girls (\u003cem\u003ek\u003c/em\u003e = 29, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.43, \u003cem\u003ep\u003c/em\u003e = .001, 95%CI[-0.68,-0.18],\u003cem\u003e\u0026nbsp;Tau\u003c/em\u003e = 4.22), even when controlling for response rates.\u003c/p\u003e\n\u003cp\u003eAdditionally, self-reported externalizing problems of girls in middle childhood also showed a significant decrease when response rate was included (\u003cem\u003ek\u003c/em\u003e = 5, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.55, \u003cem\u003ep\u003c/em\u003e = .024, 95%CI[-0.96,-0.14], \u003cem\u003eTau\u003c/em\u003e = 0.64). However, this result should be interpreted with caution because the supplementary analysis of the difference between the 1991 and 2001 versions of the YSR showed that studies using the 1991 version of the questionnaire found higher scores than the ones using the 2001 version over a crossover period between 2001-2010 when both versions were used in studies.\u003c/p\u003e\n\u003cp\u003eAmong teenagers, there was a significant decrease in externalizing problems based on parental reports (\u003cem\u003ek\u003c/em\u003e = 16, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.29, \u003cem\u003ep\u003c/em\u003e = .045, 95%CI[-0.57,-0.01], \u003cem\u003eTau\u003c/em\u003e = 3.60), which was very similar in size but no longer significant when response rate was controlled for, or when the only study using the version of the CBCL from the 1980s was excluded in a sensitivity analysis. Furthermore, when influential cases were excluded (\u003cem\u003ek\u003c/em\u003e = 1), the effect became non-significant. A decrease in parent reported externalizing problems was confirmed in samples of teenage boys (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.27, \u003cem\u003ep\u003c/em\u003e = .049, 95%CI[-0.54,0], \u003cem\u003eTau\u003c/em\u003e = 2.50), which remained after controlling for response rate. These results suggest between 2 and 6 points decrease every 10 years in externalizing problems.\u003c/p\u003e\n\u003cp\u003eInterestingly, in early childhood there were no significant changes in externalizing problems, however, the sensitivity analysis without the one study using the version of the CBCL from the 1980s showed a significant increase among both boys (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = 0.89, 95%CI[0.17,1.61], \u003cem\u003ep\u003c/em\u003e = .021) and girls (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = 0.82, 95%CI[0.17,1.47], \u003cem\u003ep\u003c/em\u003e = .019). Although, this might be due to a major change in the 2001 version of the CBCL for young children (1.5 to 5 years) compared to the 1991 version, as externalizing problems were extended with attention problems in the 2001 version, but only for this young age group. When we inspected the results only regarding the 2001 version of the CBCL, the effect size was similar but did not reach significance.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Aggression\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were no significant changes in aggression overall. However, we found a significant decrease over the last 40 years in middle childhood based on parental reports (\u003cem\u003ek\u003c/em\u003e = 47, \u003cem\u003eb\u003c/em\u003eyear = -0.18, \u003cem\u003ep\u003c/em\u003e = .009, 95%CI[-0.31,-0.05], \u003cem\u003eTau\u003c/em\u003e = 4.47 ) and self-reports (\u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear = -0.41, \u003cem\u003ep\u003c/em\u003e = .006, 95%CI[-0.66,-0.16], \u003cem\u003eTau\u003c/em\u003e = 3.27) (see Figure 2), both of which remained significant when controlling for response rate. The decrease in parent-reported aggression among children in middle childhood was confirmed in South and North American samples (\u003cem\u003ek\u003c/em\u003e = 16, \u003cem\u003eb\u003c/em\u003eyear = -0.24, \u003cem\u003ep\u003c/em\u003e = .028, 95%CI[-0.45,-0.03], \u003cem\u003eTau\u003c/em\u003e = 4.25), which was similar in size but no longer statistically-significant when response rate was controlled for. It was also confirmed in European samples when response rate was included in the model (\u003cem\u003ek\u003c/em\u003e = 14, \u003cem\u003eb\u003c/em\u003eyear = -0.27, \u003cem\u003ep\u003c/em\u003e = .042, 95%CI[-0.53,-0.01], \u003cem\u003eTau\u003c/em\u003e = 2.95). A decrease in parent-reported aggression in middle childhood among girls also appeared (\u003cem\u003ek\u003c/em\u003e = 22, \u003cem\u003eb\u003c/em\u003eyear = -0.27, \u003cem\u003ep\u003c/em\u003e = .008, 95%CI[-0.46,-0.08], \u003cem\u003eTau\u003c/em\u003e = 3.35), however, this effect was substantially reduced and no longer significant when considering response rate. Finally, there was a decrease in self-reported aggression of teenage boys when response rate was partialled out (\u003cem\u003ek\u003c/em\u003e = 10, \u003cem\u003eb\u003c/em\u003eyear = -1.06, \u003cem\u003ep\u003c/em\u003e \u0026lt; .001, 95%CI[-1.76,-0.36], \u003cem\u003eTau\u003c/em\u003e = 5.03). These trends suggest about 2 to 10 points of decrease in aggression problems every 10 years.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Deviant Behavior\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnivariate meta-regressions showed a significant decrease in teacher-reported deviant behavior (\u003cem\u003ek\u003c/em\u003e = 15, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.22, \u003cem\u003ep\u003c/em\u003e = .042, 95%CI[-0.43,-0.01]), which effect was substantially reduced and no longer significant when response rate was included. Parent report showed a similar decrease of youth\u0026rsquo;s deviant behavior but only when controlled for response rate (\u003cem\u003ek\u003c/em\u003e = 40, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.19, \u003cem\u003ep\u003c/em\u003e = .042, 95%CI[-0.37,-0.01]). A significant decrease was detected in middle childhood based on parent report when response rate was controlled for (\u003cem\u003ek\u003c/em\u003e = 33, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.15, \u003cem\u003ep\u003c/em\u003e = .009, 95%CI[-0.26,-0.04], \u003cem\u003eTau\u003c/em\u003e = 2.25), and also based on teacher report (\u003cem\u003ek\u003c/em\u003e = 15, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.22, \u003cem\u003ep\u003c/em\u003e = .035, 95%CI[-0.42,-0.02], \u003cem\u003eTau\u003c/em\u003e = 2.93), however, this effect was reduced and no longer significant when response rate was taken into account. Additionally, when excluding influential cases (\u003cem\u003ek\u003c/em\u003e =1), the effect became non-significant. A significant decrease of deviant behavior was found in Asia among middle childhood samples (\u003cem\u003ek\u003c/em\u003e = 13, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.14, \u003cem\u003ep\u003c/em\u003e = .045, 95%CI[-0.28,0], \u003cem\u003eTau\u003c/em\u003e = 1.95) but, again, this effect was smaller and no longer significant next to response rate and became non-significant when influential cases were excluded.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Internalizing Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were no significant changes in internalizing problems overall. Results among early childhood samples showed mixed results. A decrease in internalizing problems was found based on parental reports of both boys (\u003cem\u003ek\u003c/em\u003e = 8, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.58, \u003cem\u003ep\u003c/em\u003e = .037, 95%CI[-1.11,-0.05], \u003cem\u003eTau\u003c/em\u003e = 4.32) and girls (\u003cem\u003ek\u003c/em\u003e = 8, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= -0.53, \u003cem\u003ep\u003c/em\u003e = .040, 95%CI[-1.03,-0.03], \u003cem\u003eTau\u003c/em\u003e = 4.06) when response rate was included in the models, but the sensitivity analysis without the only study using the oldest version of the CBCL from the 1980s changed the direction of the effect size and showed significant increases in parent reported internalizing problems of boys (\u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.46, \u003cem\u003ep\u003c/em\u003e = .042, 95%CI[0.02,0.9]) and girls (\u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.47, \u003cem\u003ep\u003c/em\u003e = .028, 95%CI[0.07,0,87]).\u003c/p\u003e\n\u003cp\u003eThere was a significant decrease in middle childhood based on parents\u0026rsquo; report (\u003cem\u003ek\u003c/em\u003e = 60, \u003cem\u003eb\u003c/em\u003eyear = -0.10, \u003cem\u003ep\u003c/em\u003e = .033, 95%CI[-0.18,-0.01], \u003cem\u003eTau\u003c/em\u003e = 2.99), but this was no longer statistically-significant when response rate was controlled for or when studies using the oldest version of the CBCL (\u003cem\u003ek\u003c/em\u003e = 5) were excluded. This was also confirmed when the effect became non-significant when influential cases (\u003cem\u003ek\u003c/em\u003e = 3) were excluded. The same decreasing tendency was confirmed in middle childhood samples of both boys (\u003cem\u003ek\u003c/em\u003e = 29, \u003cem\u003eb\u003c/em\u003eyear = -0.22, \u003cem\u003ep\u003c/em\u003e = .036, 95%CI[-0.42,-0.02], \u003cem\u003eTau\u003c/em\u003e = 3.96) and girls (\u003cem\u003ek\u003c/em\u003e = 29, \u003cem\u003eb\u003c/em\u003eyear = -0.19, \u003cem\u003ep\u003c/em\u003e = .046, 95%CI[-0.38,0], \u003cem\u003eTau\u003c/em\u003e = 3.63), again, even after controlling for response rate, but no longer significant when studies using the oldest version of the CBCL were excluded (\u003cem\u003ek\u003c/em\u003e = 5). Additionally, when excluding influential cases (\u003cem\u003ek\u003c/em\u003e = 2), the effect for boys became non-significant. Finally, a significant decrease was found in internalizing problems among European samples of children in middle childhood based on teacher reports (\u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear = -0.17, \u003cem\u003ep\u003c/em\u003e = .038, 95%CI[-0.33,-0.01], \u003cem\u003eTau\u003c/em\u003e = 1.26), which remained when controlling for response rate.\u003c/p\u003e\n\u003cp\u003eSimilarly, significant decreases were detected among teenage boys (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = -0.32, \u003cem\u003ep\u003c/em\u003e = .044, 95%CI[-0.06,-0.01], \u003cem\u003eTau\u003c/em\u003e = 3.93) and girls (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = -0.33, \u003cem\u003ep\u003c/em\u003e = .042, 95%CI[-0.65,-0.01], \u003cem\u003eTau\u003c/em\u003e = 3.05) based on parents\u0026rsquo; report, which effects remained when response rate was included in the models, but were no longer significant when the studies using the oldest version of the CBCL from the 1980s were excluded in the sensitivity analysis. Additionally, when excluding influential cases (\u003cem\u003ek\u003c/em\u003e = 2), effect for both boys and girls became non-significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Anxiety-Depression\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was no significant change in anxious-depressed problems overall. However, a significant decrease was shown in early childhood in Asia based on parents\u0026rsquo; report (\u003cem\u003ek\u003c/em\u003e = 5, \u003cem\u003eb\u003c/em\u003eyear = -0.64, \u003cem\u003ep\u003c/em\u003e = .010, 95%CI[-0.99,-0.29]). In contrast, global parent reports showed an increase in anxiety-depression among teens (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = 0.26, \u003cem\u003ep\u003c/em\u003e = .011, 95%CI[0.07,0.45], \u003cem\u003eTau\u003c/em\u003e = 1.96) (see Figure 3), which remained even after controlling for response rate. This increasing trend in anxiety based on parent reports was confirmed in European teen samples (\u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear = 0.28, \u003cem\u003ep\u003c/em\u003e = .030, 95%CI[0.04,0.52], \u003cem\u003eTau\u003c/em\u003e = 2.27), which effect was similar in size but no longer statistically-significant when response rate was taken into account.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Somatic Complaints\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOverall, no change was detected in somatic complaints over the last 40 years. However, we found an increase in self-reported somatic complaints in teenage boys\u003cem\u003e\u0026nbsp;(k\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = 0.61, \u003cem\u003ep\u003c/em\u003e \u0026lt; .001, 95%CI[0.34,0.87], \u003cem\u003eTau\u003c/em\u003e = 2.95), which effect remained significant but substantially reduced when response rate was controlled for. No other subgroups showed significant changes (see Table A12).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Withdrawn-Depression\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOverall, there was a significant decrease in withdrawn-depressed behavior based on self-report but only when response rate was partialled out\u003cem\u003e\u0026nbsp;(k\u003c/em\u003e = 20, \u003cem\u003eb\u003c/em\u003eyear = -0.28, \u003cem\u003ep\u003c/em\u003e = .023, 95%CI[-0.52,-0.04]).\u003cem\u003e\u0026nbsp;\u003c/em\u003eA decrease with year of data collection was also detected for parent reports in middle childhood but only when response rate was controlled for (\u003cem\u003ek\u003c/em\u003e = 34, \u003cem\u003eb\u003c/em\u003eyear = -0.15, \u003cem\u003ep\u003c/em\u003e = .039, 95%CI[-0.29,-0.01], \u003cem\u003eTau\u003c/em\u003e = 3.39), which was also confirmed for samples of girls (\u003cem\u003ek\u003c/em\u003e = 18, \u003cem\u003eb\u003c/em\u003eyear = -0.34, \u003cem\u003ep\u003c/em\u003e = .044, 95%CI[-0.67,-0.01], \u003cem\u003eTau\u003c/em\u003e = 3.43). A decrease with year of data collection was also shown in parent reports of Asian samples in early childhood\u003cem\u003e\u0026nbsp;(k\u003c/em\u003e = 5, \u003cem\u003eb\u003c/em\u003eyear = -0.27, \u003cem\u003ep\u003c/em\u003e = .040, 95%CI[-0.52,-0.02], \u003cem\u003eTau\u003c/em\u003e = 0.86), however, when influential cases were excluded (\u003cem\u003ek\u003c/em\u003e = 1), the effect became non-significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Attention Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA significant increase in attention problems with year of data collection was detected based on parent reports (\u003cem\u003ek\u003c/em\u003e = 63, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.24, \u003cem\u003ep\u003c/em\u003e = .004, 95%CI[0.08,0.40]) (see Figure 4),\u003cem\u003e\u0026nbsp;\u003c/em\u003ewhich remained significant when response rate was controlled for. However, as mentioned above we found a decreasing reliability of parent-reported attention problems over the years and these reliability estimates were negatively related to the means on parent-reported attention problems. This suggests that the observed increase in parent-reported attention problems over the years might be explained by the issue of measurement variance.\u003c/p\u003e\n\u003cp\u003eWhen analyzing age groups and sexes separately, we found a significant increase in attention problems in middle childhood boys (\u003cem\u003ek\u003c/em\u003e = 24, \u003cem\u003eb\u003c/em\u003eyear = 0.29, \u003cem\u003ep\u003c/em\u003e = .031, 95%CI[0.03,0.55], \u003cem\u003eTau\u003c/em\u003e = 4.00), which effect remained when response rate was partialled out. Controversially, teacher reports of attention problems in middle childhood showed a decreasing trend with time for both boys (\u003cem\u003ek\u003c/em\u003e = 8, \u003cem\u003eb\u003c/em\u003eyear = -0.65, \u003cem\u003ep\u003c/em\u003e = .003, 95%CI[-0.98,-0.32], \u003cem\u003eTau\u003c/em\u003e = 2.34) and girls (\u003cem\u003ek\u003c/em\u003e = 8, \u003cem\u003eb\u003c/em\u003eyear = -0.56, \u003cem\u003ep\u003c/em\u003e = .033, 95%CI[-1.06,-0.06], \u003cem\u003eTau\u003c/em\u003e = 3.56), and these were similar when response rate was included in the models, although no longer statistically-significant in the case of girls. Additionally, it should be noted that continent was a confound here: all studies in these analyses were from Europe from the earlier years, and from North or South America in the later years. This might explain the difference between the trends based on parent and teacher reports.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Social Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOverall, there was a significant increase with time in self-reported social problems of youth\u003cem\u003e\u0026nbsp;(k\u003c/em\u003e = 26, \u003cem\u003eb\u003c/em\u003eyear = 0.33, \u003cem\u003ep\u003c/em\u003e = .029, 95%CI[0.11,0.85]),\u003cem\u003e\u0026nbsp;\u003c/em\u003ehowever, the effect size was reduced substantially and not significant when response rate was controlled for. This increase was significant for teens (\u003cem\u003ek\u003c/em\u003e = 19, \u003cem\u003eb\u003c/em\u003eyear = 0.48, \u003cem\u003ep\u003c/em\u003e = .013, 95%CI[0.11,0.85], \u003cem\u003eTau\u003c/em\u003e = 5.68), however, it was substantially reduced and no longer statistically-significant when response rate was also taken into account. This significant univariate increase in self-reports was also confirmed in teenage boys (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = 0.68, \u003cem\u003ep\u003c/em\u003e = .003, 95%CI[0.29,1.07], \u003cem\u003eTau\u003c/em\u003e = 4.38) and girls (\u003cem\u003ek\u003c/em\u003e = 13, \u003cem\u003eb\u003c/em\u003eyear = 0.63, \u003cem\u003ep\u003c/em\u003e = .035, 95%CI[0.05,1.21], \u003cem\u003eTau\u003c/em\u003e = 6.89), however, these effects were substantially reduced and no longer statistically-significant when response rate was controlled. Additionally, when excluding influential cases, the effects became non-significant for both boys and girls. The only increase in self-reported social problems of teens that remained after controlling for response rate was found in European samples (\u003cem\u003ek\u003c/em\u003e = 16, \u003cem\u003eb\u003c/em\u003eyear = 0.67, \u003cem\u003ep\u003c/em\u003e = .001, 95%CI[0.32,1.02], \u003cem\u003eTau\u003c/em\u003e = 2.19). Thus, there may be an increase in social problems over time, but the results may not be robust to methodological differences and response rate.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in Thought Problems\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThought problems showed an increasing trend over the last decades according to parent-report (\u003cem\u003ek\u003c/em\u003e = 40, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.09, \u003cem\u003ep\u003c/em\u003e = .006, 95%CI[0.03,0.15]) (see Figure 5), which remained even when response rate was controlled for. Self-reports of thought problems also showed an increasing tendency over time among the overall youth sample (\u003cem\u003ek\u003c/em\u003e = 24, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.47, \u003cem\u003ep\u003c/em\u003e = .044, 95%CI[0.01,0.93]), but this effect was substantially reduced and no longer statistically-significant when response rate was partialled out. We found a significant increase in parent reported thought problems in middle childhood samples (\u003cem\u003ek\u003c/em\u003e = 35, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.07, \u003cem\u003ep\u003c/em\u003e = .046, 95%CI[0,0.14], \u003cem\u003eTau\u003c/em\u003e = 1.78), which was confirmed in European samples (\u003cem\u003ek\u003c/em\u003e = 13, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.13, \u003cem\u003ep\u003c/em\u003e = .044, 95%CI[0,0.26], \u003cem\u003eTau\u003c/em\u003e = 1.63). These effects were similar but no longer significant when response rate was included in the models.\u003c/p\u003e\n\u003cp\u003eA similar increase was also found among European teenagers based on parent-report, which was only significant when response rate was also taken into account (\u003cem\u003ek\u003c/em\u003e = 8, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.14, \u003cem\u003ep\u003c/em\u003e = .030, 95%CI[0.02,0.26], \u003cem\u003eTau\u003c/em\u003e = 0.87). Self-report data of teens globally also showed an increase (\u003cem\u003ek\u003c/em\u003e = 19, \u003cem\u003eb\u003c/em\u003eyear\u0026nbsp;= 0.74, \u003cem\u003ep\u003c/em\u003e = .009, 95%CI[0.21,1.27], \u003cem\u003eTau\u003c/em\u003e = 8.19), however, this effect was substantially reduced and no longer significant when response rate was controlled for. Additionally, when influential cases were excluded, the effect became non-significant. This pattern was confirmed in European samples. When interpreting these results it should also be noted that self-report data on thought problems were found to be biased by whether the 1991 or 2001 version of the CBCL was used: studies in the crossover period of 2001-2010 using the latter found larger scores on average. This might be explained by the change in the instrument because the thought problem subscale of the 2001 version also includes items regarding self-harm. Upon closer inspection, self-report data using neither the 1991, nor the 2001 version showed no changes over time in teens. Thus, there may be increases in thought problems, but the results are not robust to methodological differences and response rate or version of the scale used.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eFindings of this cross-temporal meta-analysis of 175 included studies from around the world (44 countries) covering four decades between 1981\u0026ndash;2019 show there are very few robust changes in the mean-level of subclinical emotional and behavioral problems. In the mean-level of total problems, we found no evidence of change either based on reports of parents, teachers or youth themselves. However, stratified analysis by age groups and sexes, controlled for response rate (and thus for a possible representativeness bias), showed decreases in total problems for some groups: in early childhood (based on parent ratings), among teenage boys\u0026rsquo; (based on self-report) and in middle childhood European samples (based on teacher reports). Thus, where there were changes in total problems, they were often seen as improvements rather than deterioration over time. These findings indicate that \u0026lsquo;kids these days\u0026rsquo; are not facing more mental health problems, moreover, recent generations might be experiencing slightly better mental health than young people four decades ago.\u003c/p\u003e\u003cp\u003eThe lack of change in total behavioural and emotional problems seems to support the prevalence inflation hypothesis (Foulkes \u0026amp; Andrews, 2023) that an increase in mental health disorders is due to increasing awareness of mental health disorders as opposed to an actual increase in these mental health problems. If mental health disorders were truly on a rise, so should be the anteceding behavioural and emotional problems during childhood. Instead, based on the results of the present study it seems that the increase in mental health disorder diagnoses might be due to increased awareness of these disorders and more likelihood of receiving the diagnosis. These findings align with those of a recent Canadian longitudinal time-lag study, which found no overall increase in mental health problems across the past two generations, although the proportion of youth at risk for a \u0026ldquo;mental health crisis\u0026rdquo; was increasing (Borg et al., 2025).\u003c/p\u003e\u003cp\u003eA key finding from our meta-analysis, supported by converging evidence from multiple informants, was a decrease in externalizing problems, particularly aggression during middle childhood, based on both parent reports and self-reports, as well as a decline in self-reported aggression among adolescent boys. These positive changes in young people\u0026rsquo;s mental health might be explained by complex socio-cultural and environmental changes over the last decades, for instance: (1) increasing living standards of families and a rise in parents\u0026rsquo; educational level (Our World in Data, 2016, 2018); (2) rising public investments in prevention and intervention programs in schools or community services (e.g., social-emotional learning programs decrease externalizing problems) (Cox, 2005; Farrington \u0026amp; Welsh, 2008); (3) rising public awareness and reduced stigma towards mental disorders (Evans-Lacko et al., 2014; Pescosolido et al., 2021); (4) increased parental warmth (Collishaw et al., 2010; Garcia et al., 2020); (5) rising levels of child-care time, child-centered and time-intensive parenting (e.g., more time invested in children either spent together or organizing extracurricular activities) (Dotti Sani \u0026amp; Treas, 2016; Ishizuka, 2019; Schiffrin et al., 2015); and (6) a decrease of physical punishment in parenting practice from the 80\u0026rsquo;s (Durrant \u0026amp; Ensom, 2012; Wiggers \u0026amp; Paas, 2022). It is important to note, however, that the ASEBA battery measures offline physical and verbal aggression; it does not include cyberbullying, which may represent a form of aggression that has not declined over the past decades.\u003c/p\u003e\u003cp\u003eImportantly, there were no convergent opinions between parents, teachers and young people, about changes in other problems, such as attention problems, thought problems, anxiety-depression, social problems, or somatic complaints. However, we have to note here that opinions were not divergent (except for attention problems), but data from one informant indicated a change, while the other showed stability over time. Previous studies on secular changes also reported different opinions of informants (Maughan et al., 2008; Tick et al., 2007). Cross-informant discrepancies might display that there are genuine differences in young people\u0026rsquo;s behavior in a given social context and problems occur to be context-specific (e.g., a problem is present only at home or in the presence of the parent) (De Los Reyes et al., 2013). Alternatively, informants\u0026rsquo; concepts of what constitutes these behavioural and emotional problems might have shown different changes over the last decades. We found single-informant evidence of increases (parent reports: attention problems and thought problems for youth overall, anxiety-depression for teens; self-reports: somatic complaints of teen boys) and decreases too (parent reports: externalizing problems in middle childhood; self-reports: aggression of teen boys). These should be interpreted with caution considering that data only from one informant reflected such a change.\u003c/p\u003e\u003cp\u003eFirstly, the potential rise in thought problems indicates that parents report more symptoms like intrusive thoughts, compulsive behavior, disorganized thinking, disturbed sleep, strange behaviors or ideas, and delusions, in more recent generations of young people. Importantly, from 2001 the ASEBA battery includes a self-harm related item in the thought problems subscale, which could also contribute to the slightly rising numbers, as self-harm and suicide has been reported to increase in many countries since the 2000s (Griffin et al., 2018; Twenge, 2020; Universities UK, 2018). Various socio-cultural and environmental factors have been reported in previous studies that might explain this increasing tendency in parent-reported thought problems over the last decades: (1) increase in parental conflict or divorce, which can contribute to ruminative and self-critical thoughts (Raley \u0026amp; Sweeney, 2020; Schmuck, 2013; Zalewski et al., 2012); (2) increase in loneliness and reduced interaction with other can lead to distorted thinking and detachment from reality (Buecker et al., 2021; Twenge et al., 2019); and (3) increase in media (especially social media) use and unrealistic expectations (Twenge et al., 2019; Vuong et al., 2021). If future studies also confirm an increasing tendency in thought problems in recent and future generations of young people, we list some examples of skills that have been reported to have a positive effect on thought problems: self-regulation (Atta et al., 2024), positive thinking (Davoodi et al., 2024; Rood et al., 2012), cognitive flexibility (Y. Yang et al., 2017), problem solving (Watkins \u0026amp; Baracaia, 2002), self-compassion and mindfulness (Hilt \u0026amp; Pollak, 2012; Perestelo-Perez et al., 2017). In case such an increasing tendency is confirmed in future research, we would like to encourage both parents and educational institutions to consider nurturing these skills and strategies that can reduce thought problems and the closely associated mental health disorders (e.g., anxiety, depression).\u003c/p\u003e\u003cp\u003eSecondly, we also found evidence for an increase in parent reported anxiety-depression among adolescents and in self-reported somatic complaints of boys. There was no strong evidence for a change in withdrawn-depressed behavior. However, we have to note that there was an increase among European teenagers self-reported withdrawn-depression between 2001\u0026ndash;2019, although the study number was relatively small. These findings are partly congruent with many studies from worldwide reporting a rise in emotional problems of adolescents over the last decades (Armitage et al., 2024; Collishaw, 2015; H\u0026ouml;lling et al., 2014; Su \u0026amp; Liu, 2020; Twenge, 2020). The rise in adolescent\u0026rsquo;s emotional problems could be explained by the following examples of socio-cultural and environmental changes over the last decades: (1) increase in parental emotional problems (Schepman et al., 2011); (2) increase in technology use and screen time (in 2008 average screen time/week of an adolescent overcame active leisure time such as physical activity, arts, writing, reading and socializing), which has been directly linked to anxiety, somatic complaints, and depression (Sawhill, 2016; Twenge et al., 2018); and (3) increase in cyberbullying victimization that is linked to negative self-perception and altered impulse control (Evans-Lacko et al., 2017; Kennedy, 2021). Based on previous evidence and our findings about the increase in emotional problems, recent generations of teenagers, especially boys for whom somatic complaints are also on the rise could benefit from nurturing skills such as stress management (Sahranavard et al., 2018; Yazdani et al., 2010), mindfulness (Call et al., 2014), or emotional intelligence (Fernandez-Berrocal et al., 2006).\u003c/p\u003e\u003cp\u003eThirdly, we found some evidence for an increase in social problems of European teenagers (based on self-report). Yet, no study reported about recent cross-temporal changes in social problems in European samples, thus we highly recommend future studies to investigate this, as the social isolation due to the COVID-19 pandemic could have further worsened these symptoms.\u003c/p\u003e\u003cp\u003eFourthly, we also found evidence for a rise in parent-reported attention problems for children and adolescents, however, this might be due to a problem with measurement invariance of the CBCL\u0026rsquo;s subscale as we found a decrease in the reliability of this subscale over the years. Moreover, reliability was negatively related to the mean attention problems reported. For future studies improving the factor structure of the CBCL, the items of this subscale might need an update so that they can reliably measure attention problems of more recent generations. Additionally, teacher reports showed the opposite: a decrease in attention problems. It should be noted though that there was a low number of studies in case of teacher reports, and the results seemed to have been confounded by the continent where data was collected. Future studies should examine how parents\u0026rsquo; and teacher\u0026rsquo;s ratings regarding children\u0026rsquo;s attention problems have changed over the last decades as we cannot draw strong conclusions here.\u003c/p\u003e\u003cp\u003eIn sum, the only strong evidence for a change reflected a decrease in externalizing problems, especially aggression. For potential changes for which we found some evidence, the patterns were a mix of increases and decreases, and often not robust to methodological checks. For the most analyses, however, we found null results. In sum, our results do not support concerns regarding that kids these days are more problematic. Instead, these results suggest that the level of behavior and emotional problems in total is constant over time but there is a variation in the way young people (and their parents) experience problems: kids in the last decade seem to experience less externalizing problems which involve conflict and interaction with the social environment, but potentially more internalizing problems which reflect inner distress.\u003c/p\u003e\u003cp\u003eOverall, it is tempting to think things are getting worse. Such complaints of generational decline are ever present and a long-standing trope. Even experts mispredict secular changes in their own field highlighting the presence of researcher misconceptions (Grossman et al., 2024). This does not mean that temporal changes do not occur, but the default belief should not be declined, especially without evidence. In addition, an increase in mental health disorders has been proposed to potentially reflect an increasing awareness of these disorders and the corresponding larger likelihood that one received the diagnosis as opposed to an increase in people experiencing such mental health disorders (Foulkes \u0026amp; Andrews, 2023 ). We tried to contribute to the evidence on whether change is actually occurring in the mental health of our societies by focusing on the antecedent of mental health disorders: behavioural and emotional difficulties in childhood and adolescence. We found little reliable change in behavioural and emotional symptoms for children since the 1980s. We urge caution for researchers to believe change is occurring without evidence, and our evidence here is only one part of a larger discussion.\u003c/p\u003e"},{"header":"Limitations","content":"\u003cp\u003eImportantly, there are limitations of the present study. First of all, null results should be interpreted with caution. The present paper reports exploratory analyses in which we conducted many analyses, including ones on small sets of studies, which might have resulted in low statistical power in these cases. On the other hand, due to the fact that we conducted a large number of analyses, we cannot exclude the possibility of some incidental significant results just due to chance, which would only further heighten the fact that the majority of results show no significant change in behavior problems since the 1980s. Additionally, findings of this cross-temporal meta-analysis explored a longer time frame compared to many previous studies, this could result in no detectable change as rises and falls could cancel each other out. Although, we would like to highlight that it is also important to look at short-term (e.g., 5 years) rises in emotional and behavioral problems, as these can influence policy making (e.g., intervention programs) to target a certain problem. Importantly, another limitation was that the post COVID-19 period (from 2019) was not included in this cross-temporal meta-analysis due to a limited number of studies, and the pandemic might have had a substantial negative impact on children and adolescents mental health (Panchal et al., 2023).\u003c/p\u003e\u003cp\u003eAnother limitation was that heterogeneity was substantially high for all analysis. However, the \u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e estimate generally used for the measurement of heterogeneity have been proposed to be somewhat imprecise in case of meta-analysis of cohort and population-based studies as due to the large sample sizes, and within-study variation the \u003cem\u003eI\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e can be large (\u0026gt;\u0026thinsp;75%) even if the between-study variation is small (Coory, 2010). Although, the standard deviation of the random effect term (Tau) also showed large variations of the effect sizes among studies. In the light of this, we would like to highlight that the changes can vary by countries, certain groups of youth, or even individuals. Previous researchers caution about drawing conclusions from the individual based on population-level or ecological data, that is the so-called aggregation bias or ecological fallacy (Robinson, 1950). Along with this, it is important to highlight that there were countries with much more data collection points than other countries from each continent, for instance the Netherlands from Europe, the USA from North and South America, and China from Asia. These countries could influence the continental results.\u003c/p\u003e\u003cp\u003eConnected to the multicultural comparison in the current meta-analysis, it is important to mention that from the ASEBA battery, only the YSR have been tested for measurement invariance across multiple cultures (Stevanovic et al., 2017), thus we cannot exclude the possibility that the parent and teacher reported versions might have measurement noninvariance across cultures. This is also true within cultures but over time. It could be that certain items are noninvariant, and operate differently across time. Without the raw item-level data, measurement invariance cannot be tested, unfortunately. If behavior problems (latent) are increasing, but certain items (or raters) are operating differently and decreasing, true changes could be masked. There is an ongoing need to track changes in the subclinical level of emotional and behavioral problems with standardized questionnaires in recent cohorts of young people. In the future with moves towards standardisation of scales/measures (e.g., the Wellcomes \u0026lsquo;Common metrics in mental health research\u0026rsquo; guidance), and possibly linked health records, there may well be other opportunities to measure or triangulate with.\u003c/p\u003e\u003cp\u003eLastly, it may not be excluded that increases and decreases reflect whether informants\u0026rsquo; reports have changed over the years as expectations or tolerance for different types of behavior have also changed. However, there is a gap in the literature about possible changes in reporting biases, which might be very hard to quantify.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, between 1981-2019, our data suggest that children have not been in general decline in deviant, aggressive or mentally unhealthy behaviors. The most robust changes are actually improvements in externalizing behavior, specifically aggression. At the same time, changes in emotional and behavioral problems showed some differences according to age levels, sexes, continents, and informants that we presented in exploratory analyses in the present study. These findings indicate that kids these days have different challenges: specifically children and adolescents regarding thought problems (and perhaps attention problems), and teenagers need more support regarding anxiety and depression. Overall the results do not support concerns regarding a genuine decline in young people\u0026rsquo;s mental health.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets, all scatterplots and heterogeneity analysis generated for the meta-analysis are available in the Open Science Framework repository, https://osf.io/9yzjs/?view_only=fa6a705b8a2c4482911dc3d5c5fcd8f6.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCode availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe R code created for the meta-analysis is also available in the Open Science Framework repository, https://osf.io/9yzjs/?view_only=fa6a705b8a2c4482911dc3d5c5fcd8f6.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eB.V., Z.K.T., A.L., and J.P. contributed to the planning of the project. B.V. and Z.K.T. performed the systematic search, the inclusion process and the coding of the studies. T.K. performed the statistical analysis. W.H.C. helped in the revision of the introduction and discussion of the paper. The manuscript was revised by all authors.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eB.V. received funding for this work from the \u0026Uacute;NKP-22-4 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eDeclaration of interests\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;\u0026nbsp;\u003cbr\u003e\u0026nbsp;☐\u0026nbsp;The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003cbr\u003e\u0026nbsp;\u0026nbsp;\u003cbr\u003e\u0026nbsp;☒\u0026nbsp;The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n"},{"header":"References","content":"\u003cp\u003eReferences marked with an asterisk indicate studies included in the meta-analysis.\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003e*Achenbach, T. M. (1991a). Child behavior checklist/4–18. \u003cem\u003eUniversity of Vermont\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M. (1991b). \u003cem\u003eManual for the Teacher’s Report Form and 1991 Profile\u003c/em\u003e. University of Vermont, Department of Psychiatry.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M. (1991c). \u003cem\u003eManual for the Youth Self-Report Form and 1991 Profile\u003c/em\u003e. University of Vermont, Department of Psychiatry.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M. (2001). Manual for ASEBA school-age forms \u0026amp; profiles. \u003cem\u003eUniversity of Vermont, Research Center for Children, Youth \u0026amp; Families\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M., Dumenci, L., \u0026amp; Rescorla, L. A. (2002). Ten-year comparisons of problems and competencies for national samples of youth: Self, parent, and teacher reports. \u003cem\u003eJournal of Emotional and Behavioral Disorders\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(4), 194–203.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M., Dumenci, L., \u0026amp; Rescorla, L. A. (2003). Are American children’s problems still getting worse? A 23-year comparison. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e31\u003c/em\u003e(1), 1–11.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M., \u0026amp; Edelbrock, C. (1986). \u003cem\u003eManual for the Teacher’s Report Form and Teacher Version of the Child Behavior Profile\u003c/em\u003e. University of Vermont, Department of Psychiatry.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M., \u0026amp; Edelbrock, C. (1987). \u003cem\u003eManual for the Youth Self-Report and Profile\u003c/em\u003e. University of Vermont, Department of Psychiatry.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M., \u0026amp; Edelbrock, C. S. (1983). Manual for the child behavior checklist and revised child behavior profile. \u003cem\u003e(No Title)\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eAchenbach, T. M., \u0026amp; Rescorla, L. A. (2000). \u003cem\u003eManual for the ASEBA preschool forms and profiles\u003c/em\u003e (Vol. 30). Burlington, VT: University of Vermont, Research center for children, youth ….\u003c/li\u003e\n \u003cli\u003e*Ahmad, A., Abdul-Majeed, A. M., Siddiq, A. A., Jabar, F., Qahar, J., Rasheed, J., \u0026amp; von Knorring, A.-L. (2007). Reporting questionnaire for children as a screening instrument for child mental health problems in Iraqi Kurdistan. \u003cem\u003eTranscultural Psychiatry\u003c/em\u003e, \u003cem\u003e44\u003c/em\u003e(1), 5–26. https://doi.org/10.1177/1363461507074949\u003c/li\u003e\n \u003cli\u003e*Ajduković, M., Rajhvajn Bulat, L., \u0026amp; Sušac, N. (2018). The internalising and externalising problems of adolescents in Croatia: Socio‐demographic and family victimisation factors. \u003cem\u003eInternational Journal of Social Welfare\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(1), 88–100. https://doi.org/10.1111/ijsw.12284\u003c/li\u003e\n \u003cli\u003e*Alati, R., Najman, J. M., O’Callaghan, M., Bor, W., Williams, G. M., \u0026amp; Clavarino, A. (2009). Fetal growth and behaviour problems in early adolescence: Findings from the Mater University Study of Pregnancy. \u003cem\u003eInternational Journal of Epidemiology\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(5), 1390–1400.\u003c/li\u003e\n \u003cli\u003e*Albaugh, M. D., Nguyen, T.-V., Ducharme, S., Collins, D. L., Botteron, K. N., D’Alberto, N., Evans, A. C., Karama, S., Hudziak, J. J., \u0026amp; Brain Development Cooperative Group. (2017). Age-related volumetric change of limbic structures and subclinical anxious/depressed symptomatology in typically developing children and adolescents. \u003cem\u003eBiological Psychology\u003c/em\u003e, \u003cem\u003e124\u003c/em\u003e, 133–140.\u003c/li\u003e\n \u003cli\u003e*Alvarenga, P. G., Do Rosario, M. C., Cesar, R. C., Manfro, G. G., Moriyama, T. S., Bloch, M. H., Shavitt, R. G., Hoexter, M. Q., Coughlin, C. G., \u0026amp; Leckman, J. F. (2016). Obsessive–compulsive symptoms are associated with psychiatric comorbidities, behavioral and clinical problems: A population-based study of Brazilian school children. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e25\u003c/em\u003e(2), 175–182.\u003c/li\u003e\n \u003cli\u003e*An, S., Rauch, S. A., Maphula, A., Obida, M., Kogut, K., Bornman, R., Chevrier, J., \u0026amp; Eskenazi, B. (2022). In-utero exposure to DDT and pyrethroids and child behavioral and emotional problems at 2 years of age in the VHEMBE cohort, South Africa. \u003cem\u003eChemosphere\u003c/em\u003e, \u003cem\u003e306\u003c/em\u003e, 135569. https://doi.org/10.1016/j.chemosphere.2022.135569\u003c/li\u003e\n \u003cli\u003eArmitage, J. M., Collishaw, S., \u0026amp; Sellers, R. (2024). Explaining long-term trends in adolescent emotional problems: What we know from population-based studies. \u003cem\u003eDiscover Social Science and Health\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(1), 14. https://doi.org/10.1007/s44155-024-00076-2\u003c/li\u003e\n \u003cli\u003e*Ashford, J., Smit, F., Van Lier, P. A., Cuijpers, P., \u0026amp; Koot, H. M. (2008). Early risk indicators of internalizing problems in late childhood: A 9-year longitudinal study. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(7), 774–780.\u003c/li\u003e\n \u003cli\u003e*Athanasiou, K., Melegkovits, E., Andrie, E. K., Magoulas, C., Tzavara, C. K., Richardson, C., Greydanus, D., Tsolia, M., \u0026amp; Tsitsika, A. K. (2018). Cross-national aspects of cyberbullying victimization among 14–17-year-old adolescents across seven European countries. \u003cem\u003eBMC Public Health\u003c/em\u003e, \u003cem\u003e18\u003c/em\u003e(1), 800. https://doi.org/10.1186/s12889-018-5682-4\u003c/li\u003e\n \u003cli\u003eAtta, M. H. R., El-Gueneidy, M. M., \u0026amp; Lachine, O. A. R. (2024). The influence of an emotion regulation intervention on challenges in emotion regulation and cognitive strategies in patients with depression. \u003cem\u003eBMC Psychology\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(1), 496. https://doi.org/10.1186/s40359-024-01949-6\u003c/li\u003e\n \u003cli\u003e*Barkmann, C., \u0026amp; Schulte-Markwort, M. (2005). Emotional and behavioral problems of children and adolescents in Germany: An epidemiological screening. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e40\u003c/em\u003e, 357–366.\u003c/li\u003e\n \u003cli\u003e*Bartels, M., Hendriks, A., Mauri, M., Krapohl, E., Whipp, A., Bolhuis, K., Conde, L. C., Luningham, J., Fung Ip, H., Hagenbeek, F., Roetman, P., Gatej, R., Lamers, A., Nivard, M., van Dongen, J., Lu, Y., Middeldorp, C., van Beijsterveldt, T., Vermeiren, R., … Boomsma, D. I. (2018). Childhood aggression and the co-occurrence of behavioural and emotional problems: Results across ages 3–16 years from multiple raters in six cohorts in the EU-ACTION project. \u003cem\u003eEuropean Child and Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(9), Article 9. https://doi.org/10.1007/s00787-018-1169-1\u003c/li\u003e\n \u003cli\u003e*Barzeva, S. A., Meeus, W. H. J., \u0026amp; Oldehinkel, A. J. (2019). Social Withdrawal in Adolescence and Early Adulthood: Measurement Issues, Normative Development, and Distinct Trajectories. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e47\u003c/em\u003e(5), 865–879. https://doi.org/10.1007/s10802-018-0497-4\u003c/li\u003e\n \u003cli\u003e*Bayer, J. K., Hiscock, H., Ukoumunne, O. C., Price, A., \u0026amp; Wake, M. (2008). Early childhood aetiology of mental health problems: A longitudinal population-based study. \u003cem\u003eJournal of Child Psychology and Psychiatry and Allied Disciplines\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(11), Article 11. https://doi.org/10.1111/j.1469-7610.2008.01943.x\u003c/li\u003e\n \u003cli\u003e*Bayer, J. K., Ukoumunne, O. C., Mathers, M., Wake, M., Abdi, N., \u0026amp; Hiscock, H. (2012). Development of children’s internalising and externalising problems from infancy to five years of age. \u003cem\u003eAustralian \u0026amp; New Zealand Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e46\u003c/em\u003e(7), 659–668.\u003c/li\u003e\n \u003cli\u003e*Bedregal, P., Lermanda, V., Sierra, R., \u0026amp; Viviani, P. (2023). Risk factors associated with higher scores in internalizing and externalizing behaviors in Chilean preschoolers. \u003cem\u003eInfant Mental Health Journal\u003c/em\u003e, \u003cem\u003e44\u003c/em\u003e(5), 663–678. https://doi.org/10.1002/imhj.22082\u003c/li\u003e\n \u003cli\u003e*Begovac, I., Rudan, V., Skočić, M., Filipović, O., \u0026amp; Szirovicza, L. (2004). Comparison of self-reported and parent-reported emotional and behavioral problems in adolescents from Croatia. \u003cem\u003eCollegium Antropologicum\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e(1), 393–401.\u003c/li\u003e\n \u003cli\u003eBelsky, J., \u0026amp; Pluess, M. (2009). Beyond diathesis stress: differential susceptibility to environmental influences. \u003cem\u003ePsychological Bulletin\u003c/em\u003e, \u003cem\u003e135\u003c/em\u003e(6), 885-908.\u003c/li\u003e\n \u003cli\u003e*Berg-Nielsen, T. S., Solheim, E., Belsky, J., \u0026amp; Wichstrom, L. (2012). Preschoolers’ Psychosocial Problems: In the Eyes of the Beholder? Adding Teacher Characteristics as Determinants of Discrepant Parent–Teacher Reports. \u003cem\u003eChild Psychiatry \u0026amp; Human Development\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e(3), 393–413. https://doi.org/10.1007/s10578-011-0271-0\u003c/li\u003e\n \u003cli\u003e*Berkien, M., Louwerse, A., Verhulst, F., \u0026amp; van der Ende, J. (2012). Children’s perceptions of dissimilarity in parenting styles are associated with internalizing and externalizing behavior. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e21\u003c/em\u003e(2), 79–85. https://doi.org/10.1007/s00787-011-0234-9\u003c/li\u003e\n \u003cli\u003e*Bhola, P., Manjula, M., Rajappa, V., \u0026amp; Phillip, M. (2017). Predictors of non-suicidal and suicidal self-injurious behaviours, among adolescents and young adults in urban India. \u003cem\u003eAsian Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e29\u003c/em\u003e, 123–128.\u003c/li\u003e\n \u003cli\u003e*Bilenberg, N. (1999). The Child Behavior Checklist (CBCL) and related material: Standardization and validation in Danish population based and clinically based samples. \u003cem\u003eActa Psychiatrica Scandinavica\u003c/em\u003e, \u003cem\u003e100\u003c/em\u003e, 2–52.\u003c/li\u003e\n \u003cli\u003e*Bishop, S. A., Okagbue, H. I., \u0026amp; Odukoya, J. A. (2020). Statistical analysis of childhood and early adolescent externalizing behaviors in a middle low income country. \u003cem\u003eHeliyon\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e(2). https://www.cell.com/heliyon/pdf/S2405-8440(20)30222-X.pdf\u003c/li\u003e\n \u003cli\u003e*Bohlin, G., \u0026amp; Janols, L.-O. (2004). Behavioural problems and psychiatric symptoms in 5–13 year-old Swedish children—A comparison of parent ratings on the FTF (Five to Fifteen) with the ratings on CBCL (Child Behavior Checklist). \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e, iii14–iii22.\u003c/li\u003e\n \u003cli\u003e*Bongers, I. L., Koot, H. M., Van der Ende, J., \u0026amp; Verhulst, F. C. (2003). The normative development of child and adolescent problem behavior. \u003cem\u003eJournal of Abnormal Psychology\u003c/em\u003e, \u003cem\u003e112\u003c/em\u003e(2), 179.\u003c/li\u003e\n \u003cli\u003eBor, W., Dean, A. J., Najman, J., \u0026amp; Hayatbakhsh, R. (2014). Are child and adolescent mental health problems increasing in the 21st century? A systematic review. \u003cem\u003eAustralian \u0026amp; New Zealand Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e48\u003c/em\u003e(7), 606–616.\u003c/li\u003e\n \u003cli\u003eBorg, M. E., Heffer, T., \u0026amp; Willoughby, T. (2024). Generational Shifts in Adolescent Mental Health: A Longitudinal Time-Lag Study. \u003cem\u003eJournal of Youth and Adolescence\u003c/em\u003e, 1-12.\u003c/li\u003e\n \u003cli\u003e*Bouvette-Turcot, A.-A., Unternaehrer, E., Gaudreau, H., Lydon, J. E., Steiner, M., Meaney, M. J., \u0026amp; Team, M. R. (2017). The joint contribution of maternal history of early adversity and adulthood depression to socioeconomic status and potential relevance for offspring development. \u003cem\u003eJournal of Affective Disorders\u003c/em\u003e, \u003cem\u003e207\u003c/em\u003e, 26–31.\u003c/li\u003e\n \u003cli\u003e*Boyd, M., Kisely, S., Najman, J., \u0026amp; Mills, R. (2019). Child maltreatment and attentional problems: A longitudinal birth cohort study. \u003cem\u003eChild Abuse \u0026amp; Neglect\u003c/em\u003e, \u003cem\u003e98\u003c/em\u003e, 104170.\u003c/li\u003e\n \u003cli\u003e*Broberg, A. G., Ekeroth, K., Gustafsson, P., Hansson, K., Hägglöf, B., Ivarsson, T., \u0026amp; Larsson, B. (2001). Self-reported competencies and problems among Swedish adolescents: A normative study of the YSR. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e, 186–193.\u003c/li\u003e\n \u003cli\u003e*Brunner, R., Parzer, P., Haffner, J., Steen, R., Roos, J., Klett, M., \u0026amp; Resch, F. (2007). Prevalence and psychological correlates of occasional and repetitive deliberate self-harm in adolescents. \u003cem\u003eArchives of Pediatrics \u0026amp; Adolescent Medicine\u003c/em\u003e, \u003cem\u003e161\u003c/em\u003e(7), 641–649.\u003c/li\u003e\n \u003cli\u003eBuecker, S., Mund, M., Chwastek, S., Sostmann, M., \u0026amp; Luhmann, M. (2021). Is loneliness in emerging adults increasing over time? A preregistered cross-temporal meta-analysis and systematic review. \u003cem\u003ePsychological Bulletin\u003c/em\u003e, \u003cem\u003e147\u003c/em\u003e(8), 787.\u003c/li\u003e\n \u003cli\u003eCall, D., Miron, L., \u0026amp; Orcutt, H. (2014). Effectiveness of Brief Mindfulness Techniques in Reducing Symptoms of Anxiety and Stress. \u003cem\u003eMindfulness\u003c/em\u003e, \u003cem\u003e5\u003c/em\u003e(6), 658–668. https://doi.org/10.1007/s12671-013-0218-6\u003c/li\u003e\n \u003cli\u003e*Camfferman, R., Jansen, P. W., Rippe, R. C., Mesman, J., Derks, I. P., Tiemeier, H., Jaddoe, V., \u0026amp; Van der Veek, S. M. (2016). The association between overweight and internalizing and externalizing behavior in early childhood. \u003cem\u003eSocial Science \u0026amp; Medicine\u003c/em\u003e, \u003cem\u003e168\u003c/em\u003e, 35–42.\u003c/li\u003e\n \u003cli\u003e*Cassidy, A. R. (2016). Executive function and psychosocial adjustment in healthy children and adolescents: A latent variable modelling investigation. \u003cem\u003eChild Neuropsychology\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(3), Article 3. https://doi.org/10.1080/09297049.2014.994484\u003c/li\u003e\n \u003cli\u003e*Cederblad, M., Pruksachatkunakorn, P., Boripunkul, T., Intraprasert, S., \u0026amp; H÷÷k, B÷. (2001). Behaviour Problems and Competence in Thai Children and Youths: Teachers’, Parents’ and Subjects’ Perspectives. \u003cem\u003eTranscultural Psychiatry\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(1), 64–79. https://doi.org/10.1177/136346150103800106\u003c/li\u003e\n \u003cli\u003e*Cerniglia, L., \u0026amp; Cimino, S. (2023). Eating Disorders and Internalizing/Externalizing Symptoms in Adolescents before and during the COVID-19 Pandemic. \u003cem\u003eJournal of the American Nutrition Association\u003c/em\u003e, \u003cem\u003e42\u003c/em\u003e(5), 445–451. https://doi.org/10.1080/07315724.2022.2063206\u003c/li\u003e\n \u003cli\u003e*Cerniglia, L., Cimino, S., \u0026amp; Ammaniti, M. (2021). What are the effects of screen time on emotion regulation and academic achievements? A three-wave longitudinal study on children from 4 to 8 years of age. \u003cem\u003eJournal of Early Childhood Research\u003c/em\u003e, \u003cem\u003e19\u003c/em\u003e(2), 145–160.\u003c/li\u003e\n \u003cli\u003e*Chang, J.-C., Huang, W.-L., Chen, Y.-L., \u0026amp; Gau, S. S.-F. (2020). The mental health of immigrant mother’s offspring in Taiwan: A national epidemiological study. \u003cem\u003eJournal of the Formosan Medical Association = Taiwan Yi Zhi\u003c/em\u003e, \u003cem\u003e119\u003c/em\u003e(2), 601–609. https://doi.org/10.1016/j.jfma.2019.08.033\u003c/li\u003e\n \u003cli\u003eChen, C.-Y., Storr, C. L., Tang, G.-M., Huang, S.-L., Hsiao, C. K., \u0026amp; Chen, W. J. (2008). Early alcohol experiences and adolescent mental health: A population-based study in Taiwan. \u003cem\u003eDrug and Alcohol Dependence\u003c/em\u003e, \u003cem\u003e95\u003c/em\u003e(3), 209–218. https://doi.org/10.1016/j.drugalcdep.2008.01.018\u003c/li\u003e\n \u003cli\u003e*Chen, Y.-Y., Ho, S.-Y., Lee, P.-C., Wu, C.-K., \u0026amp; Gau, S. S.-F. (2017). Parent-child discrepancies in the report of adolescent emotional and behavioral problems in Taiwan. \u003cem\u003ePLoS One\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(6), e0178863.\u003c/li\u003e\n \u003cli\u003e*Choe, R., Sim, Y. F., Hong, C. H. L., Mohideen, S., Nadarajan, R., Yap, F., Shek, L. P.-C., Hsu, C.-Y. S., Broekman, B. F. P., \u0026amp; Ferreira, J. N. (2021). Internalizing problems are associated with oral health-related quality of life in early childhood: Outcomes from an Asian multi-ethnic prospective birth cohort. \u003cem\u003ePloS One\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(8), e0256163. https://doi.org/10.1371/journal.pone.0256163\u003c/li\u003e\n \u003cli\u003e*Christensen, H. B., \u0026amp; Bilenberg, N. (2000). Behavioural and emotional problems in children of alcoholic mothers and fathers. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(3), 219–226.\u003c/li\u003e\n \u003cli\u003eCollishaw, S. (2015). Annual research review: Secular trends in child and adolescent mental health. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e56\u003c/em\u003e(3), 370–393.\u003c/li\u003e\n \u003cli\u003eCollishaw, S., Maughan, B., Goodman, R., \u0026amp; Pickles, A. (2004). Time trends in adolescent mental health. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e45\u003c/em\u003e(8), 1350–1362.\u003c/li\u003e\n \u003cli\u003eCollishaw, S., Maughan, B., Natarajan, L., \u0026amp; Pickles, A. (2010). Trends in adolescent emotional problems in England: A comparison of two national cohorts twenty years apart. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e(8), 885–894. https://doi.org/10.1111/j.1469-7610.2010.02252.x\u003c/li\u003e\n \u003cli\u003eCoory, M. D. (2010). Comment on: Heterogeneity in meta-analysis should be expected and appropriately quantified. \u003cem\u003eInternational Journal of Epidemiology\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(3), 932–932.\u003c/li\u003e\n \u003cli\u003eCosma, A., Stevens, G., Martin, G., Duinhof, E. L., Walsh, S. D., Garcia-Moya, I., ... \u0026amp; De Looze, M. (2020). Cross-national time trends in adolescent mental well-being from 2002 to 2018 and the explanatory role of schoolwork pressure. \u003cem\u003eJournal of Adolescent Health\u003c/em\u003e, \u003cem\u003e66\u003c/em\u003e(6), S50-S58.\u003c/li\u003e\n \u003cli\u003e*Coulombe, J. A., Reid, G. J., Boyle, M. H., \u0026amp; Racine, Y. (2010). Sleep problems, tiredness, and psychological symptoms among healthy adolescents. \u003cem\u003eJournal of Pediatric Psychology\u003c/em\u003e, \u003cem\u003e36\u003c/em\u003e(1), 25–35.\u003c/li\u003e\n \u003cli\u003eCox, D. D. (2005). Evidence-based interventions using home-school collaboration. \u003cem\u003eSchool Psychology Quarterly\u003c/em\u003e, \u003cem\u003e20\u003c/em\u003e(4), 473.\u003c/li\u003e\n \u003cli\u003eCrijnen, A. A., Achenbach, T. M., \u0026amp; Verhulst, F. C. (1999). Problems reported by parents of children in multiple cultures: The Child Behavior Checklist syndrome constructs. \u003cem\u003eAmerican Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e156\u003c/em\u003e(4), 569–574.\u003c/li\u003e\n \u003cli\u003e*Cui, Y., Li, F., Leckman, J. F., Guo, L., Ke, X., Liu, J., Zheng, Y., \u0026amp; Li, Y. (2021). The prevalence of behavioral and emotional problems among Chinese school children and adolescents aged 6–16: A national survey. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e30\u003c/em\u003e, 233–241.\u003c/li\u003e\n \u003cli\u003e*Darvay, S, Gádoros, J., Joubert, K., Ágfalvi Varga Teghze-Gerber, R. \u0026amp; Rózsa, Zs., S. (1996). Effect of maturity at birth on the child behavior. \u003cem\u003eAnthropologiai. Közlemény.\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e, 165–170.\u003c/li\u003e\n \u003cli\u003eDavoodi, E., Sharifi, T., \u0026amp; Ahmadi, R. (2024). Comparison of the Effectiveness of Group Training of Positive Thinking Skills and Stress Management Based on Cognitive-Behavioral Approach on Perceived Stress and Rumination of Female Students of the First Year of High School Students with Test Anxiety. \u003cem\u003eJournal of Applied Psychological Research\u003c/em\u003e. https://japr.ut.ac.ir/article_98595_en.html\u003c/li\u003e\n \u003cli\u003eDe Los Reyes, A., Thomas, S. A., Goodman, K. L., \u0026amp; Kundey, S. M. A. (2013). Principles Underlying the Use of Multiple Informants’ Reports. \u003cem\u003eAnnual Review of Clinical Psychology\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(1), 123–149. https://doi.org/10.1146/annurev-clinpsy-050212-185617\u003c/li\u003e\n \u003cli\u003e*Dekker, M. C., Koot, H. M., van der Ende, J., \u0026amp; Verhulst, F. C. (2002). Emotional and behavioral problems in children and adolescents with and without intellectual disability. \u003cem\u003eJournal of Child Psychology and Psychiatry, and Allied Disciplines\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e(8), 1087–1098. https://doi.org/10.1111/1469-7610.00235\u003c/li\u003e\n \u003cli\u003e*Desmarais, E., Brown, K., Campbell, K., French, B. F., Putnam, S. P., Casalin, S., Linhares, M. B. M., Lecannelier, F., Wang, Z., \u0026amp; Raikkonen, K. (2021). Links between television exposure and toddler dysregulation: Does culture matter? \u003cem\u003eInfant Behavior and Development\u003c/em\u003e, \u003cem\u003e63\u003c/em\u003e, 101557.\u003c/li\u003e\n \u003cli\u003eDotti Sani, G. M., \u0026amp; Treas, J. (2016). Educational gradients in parents’ child‐care time across countries, 1965–2012. \u003cem\u003eJournal of Marriage and Family\u003c/em\u003e, \u003cem\u003e78\u003c/em\u003e(4), 1083–1096.\u003c/li\u003e\n \u003cli\u003eDudani, A., Macpherson, A., \u0026amp; Tamim, H. (2010). Childhood behavior problems and unintentional injury: A longitudinal, population-based study. \u003cem\u003eJournal of Developmental \u0026amp; Behavioral Pediatrics\u003c/em\u003e, \u003cem\u003e31\u003c/em\u003e(4), 276–285.\u003c/li\u003e\n \u003cli\u003eDurrant, J., \u0026amp; Ensom, R. (2012). Physical punishment of children: Lessons from 20 years of research. \u003cem\u003eCMAJ\u003c/em\u003e, \u003cem\u003e184\u003c/em\u003e(12), 1373–1377.\u003c/li\u003e\n \u003cli\u003e*Effenberger, P. S., Send, T. S., Gilles, M., Wolf, I. A. C., Frank, J., Bongard, S., Kumsta, R., Witt, S. H., Rietschel, M., Deuschle, M., \u0026amp; Streit, F. (2022). Urbanicity, behavior problems and HPA axis regulation in preschoolers. \u003cem\u003ePsychoneuroendocrinology\u003c/em\u003e, \u003cem\u003e137\u003c/em\u003e, 105660. https://doi.org/10.1016/j.psyneuen.2022.105660\u003c/li\u003e\n \u003cli\u003eEl Marroun, H., White, T. J., van der Knaap, N. J., Homberg, J. R., Fernandez, G., Schoemaker, N. K., Jaddoe, V. W., Hofman, A., Verhulst, F. C., \u0026amp; Hudziak, J. J. (2014). Prenatal exposure to selective serotonin reuptake inhibitors and social responsiveness symptoms of autism: Population-based study of young children. \u003cem\u003eThe British Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e205\u003c/em\u003e(2), 95–102.\u003c/li\u003e\n \u003cli\u003eEllersgaard, D., Jessica Plessen, K., Richardt Jepsen, J., Soeborg Spang, K., Hemager, N., Klee Burton, B., Jerlang Christiani, C., Gregersen, M., Søndergaard, A., \u0026amp; Uddin, M. J. (2018). Psychopathology in 7‐year‐old children with familial high risk of developing schizophrenia spectrum psychosis or bipolar disorder–The Danish High Risk and Resilience Study‐VIA 7, a population‐based cohort study. \u003cem\u003eWorld Psychiatry\u003c/em\u003e, \u003cem\u003e17\u003c/em\u003e(2), 210–219.\u003c/li\u003e\n \u003cli\u003e*Equit, M., Klein, A.-M., Braun-Bither, K., Gräber, S., \u0026amp; von Gontard, A. (2014). Elimination disorders and anxious-depressed symptoms in preschool children: A population-based study. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e, 417–423.\u003c/li\u003e\n \u003cli\u003e*Erol, N., Simsek, Z., Oner, O., \u0026amp; Munir, K. (2005). Behavioral and emotional problems among Turkish children at ages 2 to 3 years. \u003cem\u003eJournal of the American Academy of Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e44\u003c/em\u003e(1), 80–87.\u003c/li\u003e\n \u003cli\u003e*Erol, N., Simsek, Z., Oner, O., \u0026amp; Munir, K. (2008). Epidemiology of Attention Problems Among Turkish Children and Adolescents A National Study. \u003cem\u003eJOURNAL OF ATTENTION DISORDERS\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(5), Article 5. https://doi.org/10.1177/1087054707311214\u003c/li\u003e\n \u003cli\u003e*Evans, S. F., Kobrosly, R. W., Barrett, E. S., Thurston, S. W., Calafat, A. M., Weiss, B., Stahlhut, R., Yolton, K., \u0026amp; Swan, S. H. (2014). Prenatal bisphenol A exposure and maternally reported behavior in boys and girls. \u003cem\u003eNeurotoxicology\u003c/em\u003e, \u003cem\u003e45\u003c/em\u003e, 91–99. https://doi.org/10.1016/j.neuro.2014.10.003\u003c/li\u003e\n \u003cli\u003eEvans-Lacko, S., Corker, E., Williams, P., Henderson, C., \u0026amp; Thornicroft, G. (2014). Effect of the Time to Change anti-stigma campaign on trends in mental-illness-related public stigma among the English population in 2003–13: An analysis of survey data. \u003cem\u003eThe Lancet Psychiatry\u003c/em\u003e, \u003cem\u003e1\u003c/em\u003e(2), 121–128.\u003c/li\u003e\n \u003cli\u003eEvans-Lacko, S., Takizawa, R., Brimblecombe, N., King, D., Knapp, M., Maughan, B., \u0026amp; Arseneault, L. (2017). Childhood bullying victimization is associated with use of mental health services over five decades: A longitudinal nationally representative cohort study. \u003cem\u003ePsychological Medicine\u003c/em\u003e, \u003cem\u003e47\u003c/em\u003e(1), 127–135.\u003c/li\u003e\n \u003cli\u003e*Faleschini, S., Doyon, M., Arguin, M., Lepage, J.-F., Tiemeier, H., Van Lieshout, R. J., Perron, P., Bouchard, L., \u0026amp; Hivert, M.-F. (2023). Maternal Hyperglycemia in Pregnancy and Offspring Internalizing and Externalizing Behaviors. \u003cem\u003eMaternal and Child Health Journal\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(10), 1765–1773.\u003c/li\u003e\n \u003cli\u003e*Fang, Y., Raat, H., Windhorst, D. A., Fierloos, I. N., Jonkman, H., Hosman, C. M., Crone, M. R., Jansen, W., \u0026amp; van Grieken, A. (2022). The association between stressful life events and emotional and behavioral problems in children 0–7 years old: The CIKEO study. \u003cem\u003eInternational Journal of Environmental Research and Public Health\u003c/em\u003e, \u003cem\u003e19\u003c/em\u003e(3), 1650.\u003c/li\u003e\n \u003cli\u003e*Fanti, K. A., \u0026amp; Henrich, C. C. (2010). Trajectories of pure and co-occurring internalizing and externalizing problems from age 2 to age 12: Findings from the National Institute of Child Health and Human Development Study of Early Child Care. \u003cem\u003eDevelopmental Psychology\u003c/em\u003e, \u003cem\u003e46\u003c/em\u003e(5), 1159–1175. https://doi.org/10.1037/a0020659\u003c/li\u003e\n \u003cli\u003eFarrington, D. P., \u0026amp; Welsh, B. C. (2008). \u003cem\u003eSaving Children from a Life of Crime: Early Risk Factors and Effective Interventions\u003c/em\u003e. Oxford University Press.\u003c/li\u003e\n \u003cli\u003eFernandez-Berrocal, P., Alcaide, R., Extremera, N., \u0026amp; Pizarro, D. (2006). The role of emotional intelligence in anxiety and depression among adolescents. \u003cem\u003eIndividual Differences Research\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(1). https://www.academia.edu/download/30661585/PDF60among_adolescents.pdf\u003c/li\u003e\n \u003cli\u003eFine, S. L., Musci, R. J., Bass, J. K., Chipeta, E., Mafuta, E. M., Pinandari, A. W., ... \u0026amp; Blum, R. W. (2022). A multi-country study of risk and protective factors for emotional and behavioral problems among early adolescents. \u003cem\u003eJournal of Adolescent Health\u003c/em\u003e, \u003cem\u003e71\u003c/em\u003e(4), 480-487.\u003c/li\u003e\n \u003cli\u003e*Fitzpatrick, C., \u0026amp; Deehan, A. (1999). Competencies and problems of Irish children and adolescents. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(1), 17–23.\u003c/li\u003e\n \u003cli\u003e*Fombonne, E. (1992). Parent reports on behaviour and competencies among 6–11-year-old French Children. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e1\u003c/em\u003e(4), 233–243. https://doi.org/10.1007/BF02094184\u003c/li\u003e\n \u003cli\u003eFombonne, E. (1998). Increased rates of psychosocial disorders in youth. \u003cem\u003eEuropean Archives of Psychiatry and Clinical Neuroscience\u003c/em\u003e, \u003cem\u003e248\u003c/em\u003e, 14-21.\u003c/li\u003e\n \u003cli\u003eFord, T. (2008). Practitioner review: How can epidemiology help us plan and deliver effective child and adolescent mental health services?. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(9), 900-914.\u003c/li\u003e\n \u003cli\u003eFord, T., \u0026amp; Parker, C. (2016). Emotional and behavioural difficulties and mental (ill)health. \u003cem\u003eEmotional and Behavioural Difficulties\u003c/em\u003e, \u003cem\u003e21\u003c/em\u003e(1), 1–7. https://doi.org/10.1080/13632752.2016.1139300\u003c/li\u003e\n \u003cli\u003eFoulkes, L., \u0026amp; Andrews, J. L. (2023). Are mental health awareness efforts contributing to the rise in reported mental health problems? A call to test the prevalence inflation hypothesis. \u003cem\u003eNew Ideas in Psychology\u003c/em\u003e, \u003cem\u003e69\u003c/em\u003e, 101010.\u003c/li\u003e\n \u003cli\u003e*Francis, K., Katsani, G., Sotiropoulou, X., Roussos, A., \u0026amp; Roussos, C. (2007). Cigarette Smoking Among Greek Adolescents: Behavior, Attitudes, Risk, and Preventive Factors. \u003cem\u003eSubstance Use \u0026amp; Misuse\u003c/em\u003e, \u003cem\u003e42\u003c/em\u003e(8), 1323–1336. https://doi.org/10.1080/10826080701212410\u003c/li\u003e\n \u003cli\u003e*Fransson, E., Sörensen, F., Kallak, T. K., Ramklint, M., Eckerdal, P., Heimgärtner, M., Krägeloh-Mann, I., \u0026amp; Skalkidou, A. (2020). Maternal perinatal depressive symptoms trajectories and impact on toddler behavior–the importance of symptom duration and maternal bonding. \u003cem\u003eJournal of Affective Disorders\u003c/em\u003e, \u003cem\u003e273\u003c/em\u003e, 542–551.\u003c/li\u003e\n \u003cli\u003e*Frigerio, A., Cattaneo, C., Cataldo, M., Schiatti, A., Molteni, M., \u0026amp; Battaglia, M. (2004). Behavioral and emotional problems among Italian children and adolescents aged 4 to 18 years as reported by parents and teachers. \u003cem\u003eEuropean Journal of Psychological Assessment\u003c/em\u003e, \u003cem\u003e20\u003c/em\u003e(2), 124–133.\u003c/li\u003e\n \u003cli\u003eGarcia, O. F., Fuentes, M. C., Gracia, E., Serra, E., \u0026amp; Garcia, F. (2020). Parenting warmth and strictness across three generations: Parenting styles and psychosocial adjustment. \u003cem\u003eInternational Journal of Environmental Research and Public Health\u003c/em\u003e, \u003cem\u003e17\u003c/em\u003e(20), 7487.\u003c/li\u003e\n \u003cli\u003e*Garton, A. F., Zubrick, S. R., \u0026amp; Silburn, S. R. (1995). The Western Australian child health survey: A pilot study. \u003cem\u003eThe Australian and New Zealand Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e29\u003c/em\u003e(1), 48–57. https://doi.org/10.3109/00048679509075891\u003c/li\u003e\n \u003cli\u003e*Ghassabian, A., Bongers-Schokking, J. J., Henrichs, J., Jaddoe, V. W., Visser, T. J., Visser, W., de Muinck Keizer-Schrama, S. M., Hooijkaas, H., Steegers, E. A., \u0026amp; Hofman, A. (2011). Maternal thyroid function during pregnancy and behavioral problems in the offspring: The generation R study. \u003cem\u003ePediatric Research\u003c/em\u003e, \u003cem\u003e69\u003c/em\u003e(7), 454–459.\u003c/li\u003e\n \u003cli\u003e*Giles, L., Davies, M., Whitrow, M., Rumbold, A., Lynch, J., Sawyer, M., \u0026amp; Moore, V. (2011). Structured regression analyses of life course processes: An example exploring how maternal depression in early childhood affects children’s subsequent internalizing behavior. \u003cem\u003eAnnals of Epidemiology\u003c/em\u003e, \u003cem\u003e21\u003c/em\u003e(9), 654–659.\u003c/li\u003e\n \u003cli\u003e*Girard, L.-C., \u0026amp; Farkas, C. (2019). Breastfeeding and behavioural problems: Propensity score matching with a national cohort of infants in Chile. \u003cem\u003eBMJ Open\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(2), Article 2. https://doi.org/10.1136/bmjopen-2018-025058\u003c/li\u003e\n \u003cli\u003e*Glover, S. H., Pumariega, A. J., Holzer, C. E., Wise, B. K., \u0026amp; Rodriguez, M. (1999). Anxiety symptomatology in Mexican-American adolescents. \u003cem\u003eJournal of Child and Family Studies\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e, 47–57.\u003c/li\u003e\n \u003cli\u003eGonthier, C., \u0026amp; Grégoire, J. (2022). Flynn effects are biased by differential item functioning over time: A test using overlapping items in Wechsler scales. \u003cem\u003eIntelligence\u003c/em\u003e, \u003cem\u003e95\u003c/em\u003e, 101688.\u003c/li\u003e\n \u003cli\u003eGoodman, R. (1997). The Strengths and Difficulties Questionnaire: A Research Note. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(5), 581–586. https://doi.org/10.1111/j.1469-7610.1997.tb01545.x\u003c/li\u003e\n \u003cli\u003e*Gori, A., Giannini, M., Topino, E., Cacioppo, M., Palmieri, G., De Sanctis, E., Loscalzo, Y., Burgassi, C., Manzi, C., \u0026amp; Giovannelli, P. (2021). Mental health and rural communities: Prevalence of psychopathology among children and preadolescents in a mountainous area of Italy. \u003cem\u003eJ. Psychopathol\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e, 90–98.\u003c/li\u003e\n \u003cli\u003eGraves, L. V., Drozdick, L., Courville, T., Farrer, T. J., Gilbert, P. E., \u0026amp; Delis, D. C. (2021). Cohort differences on the CVLT-II and CVLT3: Evidence of a negative Flynn effect on the attention/working memory and learning trials. \u003cem\u003eThe Clinical Neuropsychologist\u003c/em\u003e, \u003cem\u003e35\u003c/em\u003e(3), 615–632.\u003c/li\u003e\n \u003cli\u003eGriffin, E., McMahon, E., McNicholas, F., Corcoran, P., Perry, I. J., \u0026amp; Arensman, E. (2018). Increasing rates of self-harm among children, adolescents and young adults: A 10-year national registry study 2007–2016. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e53\u003c/em\u003e, 663–671.\u003c/li\u003e\n \u003cli\u003e*Grigorenko, E. L., Geiser, C., Slobodskaya, H. R., \u0026amp; Francis, D. J. (2010). Cross-informant symptoms from CBCL, TRF, and YSR: Trait and method variance in a normative sample of Russian youths. \u003cem\u003ePsychological Assessment\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(4), 893.\u003c/li\u003e\n \u003cli\u003eGrossmann, I., Varnum, M. E., Hutcherson, C. A., \u0026amp; Mandel, D. R. (2024). When expert predictions fail. \u003cem\u003eTrends in Cognitive Sciences\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e(2), 113-123.\u003c/li\u003e\n \u003cli\u003e*Guerrero, M. D., Barnes, J. D., Chaput, J.-P., \u0026amp; Tremblay, M. S. (2019). Screen time and problem behaviors in children: Exploring the mediating role of sleep duration. \u003cem\u003eInternational Journal of Behavioral Nutrition and Physical Activity\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(1), 1–10.\u003c/li\u003e\n \u003cli\u003e*Guerrero, N., Gangnon, R., Curtis, M. A., Valdez, C. R., Ehrenthal, D. B., \u0026amp; Jacobs, E. A. (2021). The association between exposure to maternal depression during year 2 of a child’s life and future child problem behavior. \u003cem\u003eMaternal and Child Health Journal\u003c/em\u003e, \u003cem\u003e25\u003c/em\u003e, 731–740.\u003c/li\u003e\n \u003cli\u003e*Guilbert, A., Rolland, M., Pin, I., Thomsen, C., Sakhi, A. K., Sabaredzovic, A., Slama, R., Guichardet, K., \u0026amp; Philippat, C. (2021). Associations between a mixture of phenols and phthalates and child behaviour in a French mother-child cohort with repeated assessment of exposure. \u003cem\u003eEnvironment International\u003c/em\u003e, \u003cem\u003e156\u003c/em\u003e, 106697. https://doi.org/10.1016/j.envint.2021.106697\u003c/li\u003e\n \u003cli\u003eGutman, L. M., \u0026amp; Codiroli McMaster, N. (2020). Gendered Pathways of Internalizing Problems from Early Childhood to Adolescence and Associated Adolescent Outcomes. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e48\u003c/em\u003e(5), 703–718. https://doi.org/10.1007/s10802-020-00623-w\u003c/li\u003e\n \u003cli\u003eHaller, H., Cramer, H., Lauche, R., Gass, F., \u0026amp; Dobos, G. J. (2014). The prevalence and burden of subthreshold generalized anxiety disorder: A systematic review. \u003cem\u003eBMC Psychiatry\u003c/em\u003e, \u003cem\u003e14\u003c/em\u003e(1), 128. https://doi.org/10.1186/1471-244X-14-128\u003c/li\u003e\n \u003cli\u003e*Hannesdóttir, H., \u0026amp; Einarsdóttir, S. (1995). The Icelandic Child Mental Health Study. An epidemiological study of Icelandic children 2–18 years of age using the Child Behavior Checklist as a screening instrument. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(4), 237–248.\u003c/li\u003e\n \u003cli\u003e*Hay, D. F., van Goozen, S. H., Mundy, L., Phillips, R., Roberts, S., Meeuwsen, M., Goodyer, I., \u0026amp; Perra, O. (2017). If you go down to the woods today: Infants’ distress during a teddy bear’s picnic in relation to peer relations and later emotional problems. \u003cem\u003eInfancy\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(4), 552–570.\u003c/li\u003e\n \u003cli\u003e*Heflinger, C. A., Simpkins, C. G., \u0026amp; Combs-Orme, T. (2000). Using the CBCL to determine the clinical status of children in state custody. \u003cem\u003eChildren and Youth Services Review\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(1), 55–73.\u003c/li\u003e\n \u003cli\u003e*Hellinckx, W., Grietens, H., \u0026amp; De Munter, A. (2000). 12 Parent-reported Problem Behavior in12-16-Year Old American and Russian Children: A Cross-National Comparison. In \u003cem\u003eInternational perspectives on child and adolescent mental health\u003c/em\u003e (Vol. 1, pp. 205–222). Elsevier.\u003c/li\u003e\n \u003cli\u003e*Hellinckx, W., Grietens, H., \u0026amp; Verhulst, F. (1994). Competence and behavioral problems in 6-to 12-year-old children in Flanders (Belgium) and Holland: A cross-national comparison. \u003cem\u003eJournal of Emotional and Behavioral Disorders\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(3), 130–142.\u003c/li\u003e\n \u003cli\u003e*Henriksen, J., Nielsen, P. F., \u0026amp; Bilenberg, N. (2012). New Danish standardization of the Child Behaviour Checklist. \u003cem\u003eDanish Medical Journal\u003c/em\u003e, \u003cem\u003e59\u003c/em\u003e(7), A4462.\u003c/li\u003e\n \u003cli\u003e*Hensley, V. R. (1988). Australian normative study of the Achenbach child behaviour checklist. \u003cem\u003eAustralian Psychologist\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(3), 371–382.\u003c/li\u003e\n \u003cli\u003e*Heyerdahl, S., Kvernmo, S., \u0026amp; Wichstrøm, L. (2004). Self-reported behavioural/emotional problems in Norwegian adolescents from multiethnic areas. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e, 64–72.\u003c/li\u003e\n \u003cli\u003eHilt, L. M., \u0026amp; Pollak, S. D. (2012). Getting Out of Rumination: Comparison of Three Brief Interventions in a Sample of Youth. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e40\u003c/em\u003e(7), 1157–1165. https://doi.org/10.1007/s10802-012-9638-3\u003c/li\u003e\n \u003cli\u003e*Hoffmann, M. D., Barnes, J. D., Tremblay, M. S., \u0026amp; Guerrero, M. D. (2022). Associations between organized sport participation and mental health difficulties: Data from over 11,000 US children and adolescents. \u003cem\u003ePLoS One\u003c/em\u003e, \u003cem\u003e17\u003c/em\u003e(6), e0268583.\u003c/li\u003e\n \u003cli\u003eHögberg, B., Strandh, M., Johansson, K., \u0026amp; Petersen, S. (2023). Trends in adolescent psychosomatic complaints: A quantile regression analysis of Swedish HBSC data 1985–2017. \u003cem\u003eScandinavian Journal of Public Health\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e(4), 619–627. https://doi.org/10.1177/14034948221094497\u003c/li\u003e\n \u003cli\u003eHolland, M. L., Malmberg, J., \u0026amp; Peacock, G. G. (2017). \u003cem\u003eEmotional and behavioral problems of young children: Effective interventions in the preschool and kindergarten years\u003c/em\u003e. Guilford Publications.\u003c/li\u003e\n \u003cli\u003eHölling, H., Schlack, R., Petermann, F., Ravens-Sieberer, U., \u0026amp; Mauz, E. (2014). \u003cem\u003ePsychische Auffälligkeiten und psychosoziale Beeinträchtigungen bei Kindern und Jugendlichen im Alter von 3 bis 17 Jahren in Deutschland–Prävalenz und zeitliche Trends zu 2 Erhebungszeitpunkten (2003–2006 und 2009–2012)\u003c/em\u003e. https://edoc.rki.de/handle/176904/1894\u003c/li\u003e\n \u003cli\u003eHuang, C. (2017). Cross-informant agreement on the child behavior checklist for youths: A meta-analysis. \u003cem\u003ePsychological Reports\u003c/em\u003e, \u003cem\u003e120\u003c/em\u003e(6), 1096–1116.\u003c/li\u003e\n \u003cli\u003eInchley, J. C., Willis, M., Mabelis, J., Brown, J., \u0026amp; Currie, D. B. (2023). Inequalities in health complaints: 20-year trends among adolescents in Scotland, 1998–2018. \u003cem\u003eFrontiers in Psychology\u003c/em\u003e, \u003cem\u003e14\u003c/em\u003e, 1095117.\u003c/li\u003e\n \u003cli\u003eIshizuka, P. (2019). Social class, gender, and contemporary parenting standards in the United States: Evidence from a national survey experiment. \u003cem\u003eSocial Forces\u003c/em\u003e, \u003cem\u003e98\u003c/em\u003e(1), 31–58.\u003c/li\u003e\n \u003cli\u003eIvanova, M. Y., Achenbach, T. M., Rescorla, L. A., Dumenci, L., Almqvist, F., Bilenberg, N., Bird, H., Broberg, A. G., Dobrean, A., Döpfner, M., Erol, N., Forns, M., Hannesdottir, H., Kanbayashi, Y., Lambert, M. C., Leung, P., Minaei, A., Mulatu, M. S., Novik, T., … Verhulst, F. C. (2007). The generalizability of the Youth Self-Report syndrome structure in 23 societies. \u003cem\u003eJournal of Consulting and Clinical Psychology\u003c/em\u003e, \u003cem\u003e75\u003c/em\u003e(5), 729–738. https://doi.org/10.1037/0022-006X.75.5.729\u003c/li\u003e\n \u003cli\u003eIvanova, M. Y., Achenbach, T. M., Rescorla, L. A., Guo, J., Althoff, R. R., Kan, K.-J., Almqvist, F., Begovac, I., Broberg, A. G., Chahed, M., Da Rocha, M. M., Dobrean, A., Döepfner, M., Erol, N., Fombonne, E., Fonseca, A. C., Forns, M., Frigerio, A., Grietens, H., … Verhulst, F. C. (2019). Testing Syndromes of Psychopathology in Parent and Youth Ratings Across Societies. \u003cem\u003eJournal of Clinical Child \u0026amp; Adolescent Psychology\u003c/em\u003e, \u003cem\u003e48\u003c/em\u003e(4), 596–609. https://doi.org/10.1080/15374416.2017.1405352\u003c/li\u003e\n \u003cli\u003eIvanova, M. Y., Dobrean, A., Dopfner, M., Erol, N., Fombonne, E., Fonseca, A. C., Frigerio, A., Grietens, H., Hannesdottir, H., Kanbayashi, Y., Lambert, M., Achenbach, T. M., Larsson, B., Leung, P., Liu, X., Minaei, A., Mulatu, M. S., Novik, T. S., Oh, K. J., … Chen, W. J. (2007). Testing the 8-syndrome structure of the child behavior checklist in 30 societies. \u003cem\u003eJournal of Clinical Child and Adolescent Psychology : The Official Journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53\u003c/em\u003e, \u003cem\u003e36\u003c/em\u003e(3), Article 3. https://doi.org/10.1080/15374410701444363\u003c/li\u003e\n \u003cli\u003e*Jansen, J., Van Schaik, G., Renes, R., \u0026amp; Lam, T. (2010). The effect of a national mastitis control program on the attitudes, knowledge, and behavior of farmers in the Netherlands. \u003cem\u003eJournal of Dairy Science\u003c/em\u003e, \u003cem\u003e93\u003c/em\u003e(12), 5737–5747.\u003c/li\u003e\n \u003cli\u003eJohnson, J. C. S., Byrne, G. J., \u0026amp; Pelecanos, A. M. (2022). The prevalence of subthreshold psychiatric symptoms and associations with alcohol and substance use disorders: From a nationally representative survey of 36,309 adults. \u003cem\u003eBMC Psychiatry\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(1), 270. https://doi.org/10.1186/s12888-022-03834-1\u003c/li\u003e\n \u003cli\u003eJones, C. J., \u0026amp; Meredith, W. (2000). Developmental paths of psychological health from early adolescence to later adulthood. \u003cem\u003ePsychology and Aging\u003c/em\u003e, \u003cem\u003e15\u003c/em\u003e(2), 351.\u003c/li\u003e\n \u003cli\u003e*Jozefiak, T., Larsson, B., Wichstrøm, L., \u0026amp; Rimehaug, T. (2012). Competence and emotional/behavioural problems in 7-16-year-old Norwegian school children as reported by parents. \u003cem\u003eNordic Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e66\u003c/em\u003e(5), 311–319. https://doi.org/10.3109/08039488.2011.638934\u003c/li\u003e\n \u003cli\u003e*Kaess, M., Parzer, P., Haffner, J., Steen, R., Roos, J., Klett, M., Brunner, R., \u0026amp; Resch, F. (2011). Explaining gender differences in non-fatal suicidal behaviour among adolescents: A population-based study. \u003cem\u003eBMC Public Health\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e, 1–7.\u003c/li\u003e\n \u003cli\u003e*Kahr Nilsson, K., Landorph, S., Houmann, T., Olsen, E. M., \u0026amp; Skovgaard, A. M. (2019). Developmental and mental health characteristics of children exposed to psychosocial adversity and stressors at the age of 18-months: Findings from a population-based cohort study. \u003cem\u003eInfant Behavior \u0026amp; Development\u003c/em\u003e, \u003cem\u003e57\u003c/em\u003e, 101319. https://doi.org/10.1016/j.infbeh.2019.04.001\u003c/li\u003e\n \u003cli\u003e*Kapi, A., Veltsista, A., Sovio, U., Järvelin, M.-R., \u0026amp; Bakoula, C. (2007). Comparison of self-reported emotional and behavioural problems in adolescents from Greece and Finland. \u003cem\u003eActa Paediatrica (Oslo, Norway : 1992)\u003c/em\u003e, \u003cem\u003e96\u003c/em\u003e(8), 1174–1179. https://doi.org/10.1111/j.1651-2227.2007.00370.x\u003c/li\u003e\n \u003cli\u003e*Kariuki, S. M., Abubakar, A., Kombe, M., Kazungu, M., Odhiambo, R., Stein, A., \u0026amp; Newton, C. R. (2018). Prevalence, risk factors and behavioural and emotional comorbidity of acute seizures in young Kenyan children: A population-based study. \u003cem\u003eBMC Medicine\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(1), 1–12.\u003c/li\u003e\n \u003cli\u003e*Kekkonen, V. K., Kivimäki, P., Valtonen, H., Tolmunen, T., Lehto, S. M., Hintikka, J., \u0026amp; Laukkanen, E. (2015). Psychosocial problems in adolescents associated with frequent health care use. \u003cem\u003eFamily Practice\u003c/em\u003e, \u003cem\u003e32\u003c/em\u003e(3), 305–310. https://doi.org/10.1093/fampra/cmu090\u003c/li\u003e\n \u003cli\u003eKennedy, R. S. (2021). Bullying Trends in the United States: A Meta-Regression. \u003cem\u003eTrauma, Violence, \u0026amp; Abuse\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e(4), 914–927. https://doi.org/10.1177/1524838019888555\u003c/li\u003e\n \u003cli\u003e*Kerr, D. C., Lunkenheimer, E. S., \u0026amp; Olson, S. L. (2007). Assessment of child problem behaviors by multiple informants: A longitudinal study from preschool to school entry. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e48\u003c/em\u003e(10), 967–975.\u003c/li\u003e\n \u003cli\u003eKhan, M., Minbashian, A., \u0026amp; MacCann, C. (2021). College students in the western world are becoming less emotionally intelligent: A cross‐temporal meta‐analysis of trait emotional intelligence. \u003cem\u003eJournal of Personality\u003c/em\u003e, \u003cem\u003e89\u003c/em\u003e(6), 1176–1190.\u003c/li\u003e\n \u003cli\u003eKim, H., Choi, J., \u0026amp; Oh, Y. (2021). The impact of maternal personality traits on behavioral problems in preschool-aged children: A population-based panel study in South Korea. \u003cem\u003eArchives of Women’s Mental Health\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(2), 321–328.\u003c/li\u003e\n \u003cli\u003e*Klahr, A. M., Klump, K. L., \u0026amp; Burt, S. A. (2014). The etiology of the association between child antisocial behavior and maternal negativity varies across aggressive and non-aggressive rule-breaking forms of antisocial behavior. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e42\u003c/em\u003e, 1299–1311.\u003c/li\u003e\n \u003cli\u003e*Klassen, A. F., Lee, S. K., Raina, P., Chan, H. W. P., Matthew, D., \u0026amp; Brabyn, D. (2004). Health status and health-related quality of life in a population-based sample of neonatal intensive care unit graduates. \u003cem\u003ePediatrics\u003c/em\u003e, \u003cem\u003e113\u003c/em\u003e(3 Pt 1), 594–600. https://doi.org/10.1542/peds.113.3.594\u003c/li\u003e\n \u003cli\u003e*Knudsen, A. K., Ystrom, E., Skogen, J. C., \u0026amp; Torgersen, L. (2015). Maternal heavy alcohol use and toddler behavior problems: A fixed effects regression analysis. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e, 1269–1277.\u003c/li\u003e\n \u003cli\u003e*Kobrosly, R. W., Evans, S., Miodovnik, A., Barrett, E. S., Thurston, S. W., Calafat, A. M., \u0026amp; Swan, S. H. (2014). Prenatal phthalate exposures and neurobehavioral development scores in boys and girls at 6–10 years of age. \u003cem\u003eEnvironmental Health Perspectives\u003c/em\u003e, \u003cem\u003e122\u003c/em\u003e(5), 521–528.\u003c/li\u003e\n \u003cli\u003e*Koenig, J., Oelkers-Ax, R., Parzer, P., Haffner, J., Brunner, R., Resch, F., \u0026amp; Kaess, M. (2015). The association of self-injurious behaviour and suicide attempts with recurrent idiopathic pain in adolescents: Evidence from a population-based study. \u003cem\u003eChild and Adolescent Psychiatry and Mental Health\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e, 1–9.\u003c/li\u003e\n \u003cli\u003eKotov, R., Krueger, R. F., Watson, D., Achenbach, T. M., Althoff, R. R., Bagby, R. M., ... \u0026amp; Zimmerman, M. (2017). The Hierarchical Taxonomy of Psychopathology (HiTOP): A dimensional alternative to traditional nosologies. \u003cem\u003eJournal of Abnormal Psychology\u003c/em\u003e, \u003cem\u003e126\u003c/em\u003e(4), 454.\u003c/li\u003e\n \u003cli\u003e*Kristensen, S., Henriksen, T. B., \u0026amp; Bilenberg, N. (2010). The Child Behavior Checklist for Ages 1.5–5 (CBCL/1½–5): Assessment and analysis of parent-and caregiver-reported problems in a population-based sample of Danish preschool children. \u003cem\u003eNordic Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e64\u003c/em\u003e(3), 203–209.\u003c/li\u003e\n \u003cli\u003e*Lambert, M. C., \u0026amp; Lyubansky, M. (1999). Behavior and emotional problems among Jamaican children and adolescents: An epidemiological survey of parent, teacher, and self-reports for ages 6–18 years. \u003cem\u003eInternational Journal of Intercultural Relations\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(5), 727–751.\u003c/li\u003e\n \u003cli\u003e*Lansford, J. E., Malone, P. S., Dodge, K. A., Crozier, J. C., Pettit, G. S., \u0026amp; Bates, J. E. (2006). A 12-year prospective study of patterns of social information processing problems and externalizing behaviors. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e34\u003c/em\u003e, 709–718.\u003c/li\u003e\n \u003cli\u003e*Larsson, B., \u0026amp; Drugli, M. B. (2011). School competence and emotional/behavioral problems among Norwegian school children as rated by teachers on the Teacher Report Form. \u003cem\u003eScandinavian Journal of Psychology\u003c/em\u003e, \u003cem\u003e52\u003c/em\u003e(6), 553–559. https://doi.org/10.1111/j.1467-9450.2011.00889.x\u003c/li\u003e\n \u003cli\u003e*Larsson, B., \u0026amp; Frisk, M. (1999). Social competence and emotional/behaviour problems in 6–16 year-old Swedish school children. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(1), 24–33.\u003c/li\u003e\n \u003cli\u003e*Li, Y.-C., Kwan, M. Y., King-Dowling, S., Rodriguez, M. C., \u0026amp; Cairney, J. (2021). Does physical activity and BMI mediate the association between DCD and internalizing problems in early childhood? A partial test of the Environmental Stress Hypothesis. \u003cem\u003eHuman Movement Science\u003c/em\u003e, \u003cem\u003e75\u003c/em\u003e, 102744.\u003c/li\u003e\n \u003cli\u003e*Liang, Y., Zhou, Y., Ruzek, J. I., \u0026amp; Liu, Z. (2020). Patterns of childhood trauma and psychopathology among Chinese rural-to-urban migrant children. \u003cem\u003eChild Abuse \u0026amp; Neglect\u003c/em\u003e, \u003cem\u003e108\u003c/em\u003e, 104691.\u003c/li\u003e\n \u003cli\u003e*Lisi, G., Rossi, R., Ribolsi, M., Di Lorenzo, G., Parisi, C., Siracusano, M., Morciano, L., De Stefano, A., Pesaresi, A., Niolu, C., Palombi, L., \u0026amp; Siracusano, A. (2020). ‘Too many BeEPs in our teens!’ Behavioral and emotional problems in a large group of Italian adolescents. \u003cem\u003ePsychological Medicine\u003c/em\u003e, 1–10. https://doi.org/10.1017/S0033291720002767\u003c/li\u003e\n \u003cli\u003e*Liu, J., Cheng, H., \u0026amp; Leung, P. W. (2011). The application of the preschool child behavior checklist and the caregiver–teacher report form to mainland chinese children: Syndrome structure, gender differences, country effects, and inter-informant agreement. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e, 251–264.\u003c/li\u003e\n \u003cli\u003e*Liu, X., Kurita, H., Guo, C., Miyake, Y., Ze, J., \u0026amp; Cao, H. (1999). Prevalence and risk factors of behavioral and emotional problems among Chinese children aged 6 through 11 years. \u003cem\u003eJournal of the American Academy of Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(6), 708–715.\u003c/li\u003e\n \u003cli\u003e*Liu, X., Kurita, H., Guo, C., Tachimori, H., Ze, J., \u0026amp; Okawa, M. (2000). Behavioral and emotional problems in Chinese children: Teacher reports for ages 6 to 11. \u003cem\u003eJournal of Child Psychology and Psychiatry, and Allied Disciplines\u003c/em\u003e, \u003cem\u003e41\u003c/em\u003e(2), 253–260.\u003c/li\u003e\n \u003cli\u003e*Loftus, C. T., Ni, Y., Szpiro, A. A., Hazlehurst, M. F., Tylavsky, F. A., Bush, N. R., Sathyanarayana, S., Carroll, K. N., Young, M., \u0026amp; Karr, C. J. (2020). Exposure to ambient air pollution and early childhood behavior: A longitudinal cohort study. \u003cem\u003eEnvironmental Research\u003c/em\u003e, \u003cem\u003e183\u003c/em\u003e, 109075.\u003c/li\u003e\n \u003cli\u003e*Loo, S. K., \u0026amp; Rapport, M. D. (1998). Ethnic variations in children’s problem behaviors: A cross-sectional, developmental study of Hawaii school children. \u003cem\u003eThe Journal of Child Psychology and Psychiatry and Allied Disciplines\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(4), 567–575.\u003c/li\u003e\n \u003cli\u003e*Luan, M., Zhang, X., Fang, G., Liang, H., Yang, F., Song, X., Chen, Y., Yuan, W., \u0026amp; Miao, M. (2022). Preconceptional paternal alcohol consumption and the risk of child behavioral problems: A prospective cohort study. \u003cem\u003eScientific Reports\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(1), 1508.\u003c/li\u003e\n \u003cli\u003e*Machado, B. C., Dias, P., Lima, V. S., Campos, J., \u0026amp; Gonçalves, S. (2016). Prevalence and correlates of picky eating in preschool-aged children: A population-based study. \u003cem\u003eEating Behaviors\u003c/em\u003e, \u003cem\u003e22\u003c/em\u003e, 16–21.\u003c/li\u003e\n \u003cli\u003e*Machado, B. C., Dias, P., Lima, V. S., Carneiro, A., \u0026amp; Gonçalves, S. (2021). Frequency and correlates of picky eating and overeating in school-aged children: A Portuguese population-based study. \u003cem\u003eJournal of Child and Family Studies\u003c/em\u003e, \u003cem\u003e30\u003c/em\u003e, 1198–1213.\u003c/li\u003e\n \u003cli\u003eMaughan, B., Collishaw, S., Meltzer, H., \u0026amp; Goodman, R. (2008). Recent trends in UK child and adolescent mental health. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e, 305–310.\u003c/li\u003e\n \u003cli\u003eMcGorry, P. D., Mei, C., Dalal, N., Alvarez-Jimenez, M., Blakemore, S. J., Browne, V., ... \u0026amp; Killackey, E. (2024). The Lancet Psychiatry Commission on youth mental health. \u003cem\u003eThe Lancet Psychiatry\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(9), 731-774.\u003c/li\u003e\n \u003cli\u003e*McKelvey, R. S., Davies, L. C., Sang, D. L., Pickering, K. R., \u0026amp; Tu, H. C. (1999). Problems and competencies reported by parents of Vietnamese children in Hanoi. \u003cem\u003eJournal of the American Academy of Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(6), 731–737.\u003c/li\u003e\n \u003cli\u003e*McKnight, C. G., Huebner, E. S., \u0026amp; Suldo, S. (2002). Relationships among stressful life events, temperament, problem behavior, and global life satisfaction in adolescents. \u003cem\u003ePsychology in the Schools\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(6), 677–687.\u003c/li\u003e\n \u003cli\u003e*Miller, A. R., Kohen, D., \u0026amp; Johnston, C. (2008). Child characteristics and receipt of stimulant medications: A population-based study. \u003cem\u003eAmbulatory Pediatrics\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(3), 175–181.\u003c/li\u003e\n \u003cli\u003eMossin, M. H., Aaby, J. B., Dalgård, C., Lykkedegn, S., Christesen, H. T., \u0026amp; Bilenberg, N. (2017). Inverse associations between cord vitamin D and attention deficit hyperactivity disorder symptoms: A child cohort study. \u003cem\u003eAustralian \u0026amp; New Zealand Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e(7), 703–710.\u003c/li\u003e\n \u003cli\u003e*Motti-Stefanidi, F., Tsiantis, J., \u0026amp; Richardson, S. (1993). Epidemiology of behavioural and emotional problems of primary schoolchildren in Greece. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e, 111–118.\u003c/li\u003e\n \u003cli\u003eMurray, D. W., Rosanbalm, K. D., Christopoulos, C., \u0026amp; Hamoudi, A. (2015). \u003cem\u003eSelf-regulation and toxic stress: Foundations for understanding self-regulation from an applied developmental perspective\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eMustonen, A., Alakokkare, A.-E., Salom, C., Hurtig, T., Levola, J., Scott, J. G., Miettunen, J., \u0026amp; Niemelä, S. (2021). Age of first alcohol intoxication and psychiatric disorders in young adulthood—A prospective birth cohort study. \u003cem\u003eAddictive Behaviors\u003c/em\u003e, \u003cem\u003e118\u003c/em\u003e, 106910. https://doi.org/10.1016/j.addbeh.2021.106910\u003c/li\u003e\n \u003cli\u003e*Nøvik, T. S. (1999). Validity of the Child Behaviour Checklist in a Norwegian sample. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(4), 247–254.\u003c/li\u003e\n \u003cli\u003e*Obando, D., Hill, J., Sharp, H., Pickles, A., Fisher, L., \u0026amp; Wright, N. (2022). Synergy between callous–unemotional traits and aggression in preschool children: Cross-informant and cross-cultural replication in the UK Wirral Child Health and Development Study, and the Colombian La Sabana Parent–Child Study. \u003cem\u003eDevelopment and Psychopathology\u003c/em\u003e, \u003cem\u003e34\u003c/em\u003e(3), 1079–1087.\u003c/li\u003e\n \u003cli\u003e*Obot, I. S., \u0026amp; Anthony, J. C. (2004). Mental Health Problems in Adolescent Children of Alcohol Dependent Parents: Epidemiologic Research with a Nationally Representative Sample. \u003cem\u003eJournal of Child \u0026amp; Adolescent Substance Abuse\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e(4), 83–96. https://doi.org/10.1300/J029v13n04_06\u003c/li\u003e\n \u003cli\u003eOerbeck, B., Overgaard, K. R., Pripp, A. H., Reichborn-Kjennerud, T., Aase, H., \u0026amp; Zeiner, P. (2020). Early predictors of ADHD: evidence from a prospective birth cohort. \u003cem\u003eJournal of Attention Disorders\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(12), 1685–1692.\u003c/li\u003e\n \u003cli\u003e*Okada, M., Otaga, M., Tsutsui, T., Tachimori, H., Kitamura, S., Higuchi, S., \u0026amp; Mishima, K. (2018). Association of sleep with emotional and behavioral problems among abused children and adolescents admitted to residential care facilities in Japan. \u003cem\u003ePloS One\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e(6), e0198123.\u003c/li\u003e\n \u003cli\u003eOlkin, I., \u0026amp; Gleser, L. (2009). Stochastically dependent effect sizes. \u003cem\u003eThe Handbook of Research Synthesis and Meta-Analysis\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e, 357–376.\u003c/li\u003e\n \u003cli\u003e*Öncü, B., Öner, Ö., Öner, P., Erol, N., Aysev, A., \u0026amp; Canat, S. (2004). Symptoms defined by parents’ and teachers’ ratings in attention-deficit hyperactivity disorder: Changes with age. \u003cem\u003eThe Canadian Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(7), 487–491.\u003c/li\u003e\n \u003cli\u003eOtterman, D. L., Koopman-Verhoeff, M. E., White, T. J., Tiemeier, H., Bolhuis, K., \u0026amp; Jansen, P. W. (2019). Executive functioning and neurodevelopmental disorders in early childhood: A prospective population-based study. \u003cem\u003eChild and Adolescent Psychiatry and Mental Health\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e, 1–12.\u003c/li\u003e\n \u003cli\u003eOur World in Data. (2016). \u003cem\u003eWorld population living in extreme poverty\u003c/em\u003e. https://ourworldindata.org/grapher/world-population-in-extreme-poverty-absolute?stackMode=relative\u003c/li\u003e\n \u003cli\u003eOur World in Data. (2018). \u003cem\u003eWorld population by level of education\u003c/em\u003e. https://ourworldindata.org/grapher/projection-of-world-population-SSP2-IIASA\u003c/li\u003e\n \u003cli\u003ePage, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., Shamseer, L., Tetzlaff, J. M., Akl, E. A., \u0026amp; Brennan, S. E. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. \u003cem\u003eBmj\u003c/em\u003e, \u003cem\u003e372\u003c/em\u003e. https://www.bmj.com/content/372/bmj.n71.short\u003c/li\u003e\n \u003cli\u003ePanchal, U., Vaquerizo-Serrano, J. D., Conde-Ghigliazza, I., Genc, H. A., Marchini, S., Pociute, K., Ocakoğlu, B. K., Sanchez-Roman, S., Ori, D., \u0026amp; Catalan, A. (2023). Anxiety symptoms and disorders during the COVID-19 pandemic in children and adolescents: Systematic review and meta-analysis. \u003cem\u003eThe European Journal of Psychiatry\u003c/em\u003e, \u003cem\u003e37\u003c/em\u003e(4), 100218.\u003c/li\u003e\n \u003cli\u003ePerestelo-Perez, L., Barraca, J., Peñate, W., Rivero-Santana, A., \u0026amp; Alvarez-Perez, Y. (2017). Mindfulness-based interventions for the treatment of depressive rumination: Systematic review and meta-analysis. \u003cem\u003eInternational Journal of Clinical and Health Psychology\u003c/em\u003e, \u003cem\u003e17\u003c/em\u003e(3), 282–295. https://doi.org/10.1016/j.ijchp.2017.07.004\u003c/li\u003e\n \u003cli\u003ePescosolido, B. A., Halpern-Manners, A., Luo, L., \u0026amp; Perry, B. (2021). Trends in public stigma of mental illness in the US, 1996-2018. \u003cem\u003eJAMA Network Open\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(12), e2140202–e2140202.\u003c/li\u003e\n \u003cli\u003e*Pettit, G. S., Bates, J. E., Dodge, K. A., \u0026amp; Meece, D. W. (1999). The impact of after‐school peer contact on early adolescent externalizing problems is moderated by parental monitoring, perceived neighborhood safety, and prior adjustment. \u003cem\u003eChild Development\u003c/em\u003e, \u003cem\u003e70\u003c/em\u003e(3), 768–778.\u003c/li\u003e\n \u003cli\u003ePiao, J., Huang, Y., Han, C., Li, Y., Xu, Y., Liu, Y., \u0026amp; He, X. (2022). Alarming changes in the global burden of mental disorders in children and adolescents from 1990 to 2019: A systematic analysis for the Global Burden of Disease study. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e31\u003c/em\u003e(11), 1827–1845. https://doi.org/10.1007/s00787-022-02040-4\u003c/li\u003e\n \u003cli\u003e*Prinzie, P., Onghena, P., \u0026amp; Hellinckx, W. (2005). Parent and child personality traits and children’s externalizing problem behavior from age 4 to 9 years: A cohort-sequential latent growth curve analysis. \u003cem\u003eMerrill-Palmer Quarterly (1982-)\u003c/em\u003e, 335–366.\u003c/li\u003e\n \u003cli\u003e*Prinzie, P., Onghena, P., \u0026amp; Hellinckx, W. (2006). A cohort-sequential multivariate latent growth curve analysis of normative CBCL aggressive and delinquent problem behavior: Associations with harsh discipline and gender. \u003cem\u003eInternational Journal of Behavioral Development\u003c/em\u003e, \u003cem\u003e30\u003c/em\u003e(5), 444–459. https://doi.org/10.1177/0165025406071901\u003c/li\u003e\n \u003cli\u003e*Propper, C. B., McLaughlin, K., Goldblum, J., Camerota, M., Gueron-Sela, N., Mills-Koonce, W. R., \u0026amp; Wagner, N. J. (2022). Parenting and maternal reported child sleep problems in infancy predict school-age aggression and inattention. \u003cem\u003eSleep Health\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(1), 62–68.\u003c/li\u003e\n \u003cli\u003eProtzko, J. (2020). Kids These Days! Increasing delay of gratification ability over the past 50 years in children. \u003cem\u003eIntelligence\u003c/em\u003e, \u003cem\u003e80\u003c/em\u003e, 101451.\u003c/li\u003e\n \u003cli\u003eProtzko, J., \u0026amp; Schooler, J. W. (2019). Kids these days: Why the youth of today seem lacking. \u003cem\u003eScience Advances\u003c/em\u003e, \u003cem\u003e5\u003c/em\u003e(10), eaav5916.\u003c/li\u003e\n \u003cli\u003eProtzko, J., \u0026amp; Schooler, J. W. (2022). Who denigrates today’s youth?: The role of age, implicit theories, and sharing the same negative trait. \u003cem\u003eFrontiers in Psychology\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e, 723515.\u003c/li\u003e\n \u003cli\u003e*Quaak, I., De Cock, M., De Boer, M., Lamoree, M., Leonards, P., \u0026amp; Van de Bor, M. (2016). Prenatal exposure to perfluoroalkyl substances and behavioral development in children. \u003cem\u003eInternational Journal of Environmental Research and Public Health\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e(5), 511.\u003c/li\u003e\n \u003cli\u003eR Core Team. (2021). \u003cem\u003eR: A language and environment for statistical computing. R Foundation for Statistical Computing\u003c/em\u003e [Computer software]. https://www.R-project.org/\u003c/li\u003e\n \u003cli\u003e*Raadal, M., Milgrom, P., Cauce, A. M., \u0026amp; Mancl, L. (1994). Behavior problems in 5− to 11-year-old children from low-income families. \u003cem\u003eJournal of the American Academy of Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e33\u003c/em\u003e(7), 1017–1025.\u003c/li\u003e\n \u003cli\u003eRaley, R. K., \u0026amp; Sweeney, M. M. (2020). Divorce, repartnering, and stepfamilies: A decade in review. \u003cem\u003eJournal of Marriage and Family\u003c/em\u003e, \u003cem\u003e82\u003c/em\u003e(1), 81–99.\u003c/li\u003e\n \u003cli\u003e*Reijneveld, S. A., De Kleine, M., van Baar, A. L., Kollée, L. A., Verhaak, C. M., Verhulst, F. C., \u0026amp; Verloove-Vanhorick, S. P. (2006). Behavioural and emotional problems in very preterm and very low birthweight infants at age 5 years. \u003cem\u003eArchives of Disease in Childhood-Fetal and Neonatal Edition\u003c/em\u003e, \u003cem\u003e91\u003c/em\u003e(6), F423–F428.\u003c/li\u003e\n \u003cli\u003e*Reijneveld, S. A., Wiegersma, P. A., Ormel, J., Verhulst, F. C., Vollebergh, W. A., \u0026amp; Jansen, D. E. (2014). Adolescents’ use of care for behavioral and emotional problems: Types, trends, and determinants. \u003cem\u003ePLoS One\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(4), e93526.\u003c/li\u003e\n \u003cli\u003eRescorla, L. A., Achenbach, T. M., Ginzburg, S., Ivanova, M., Dumenci, L., Almqvist, F., Bathiche, M., Bilenberg, N., Bird, H., Domuta, A., Erol, N., Fombonne, E., Fonseca, A., Frigerio, A., Kanbayashi, Y., Lambert, M. C., Liu, X., Leung, P., Minaei, A., … Verhulst, F. (2007). Consistency of Teacher-Reported Problems for Students in 21 Countries. \u003cem\u003eSchool Psychology Review\u003c/em\u003e, \u003cem\u003e36\u003c/em\u003e(1), 91–110. https://doi.org/10.1080/02796015.2007.12087954\u003c/li\u003e\n \u003cli\u003eRescorla, L. A., Achenbach, T. M., Ivanova, M. Y., Harder, V. S., Otten, L., Bilenberg, N., Bjarnadottir, G., Capron, C., De Pauw, S. S. W., Dias, P., Dobrean, A., Döpfner, M., Duyme, M., Eapen, V., Erol, N., Esmaeili, E. M., Ezpeleta, L., Frigerio, A., Fung, D. S. S., … Verhulst, F. C. (2011). International Comparisons of Behavioral and Emotional Problems in Preschool Children: Parents’ Reports From 24 Societies. \u003cem\u003eJournal of Clinical Child \u0026amp; Adolescent Psychology\u003c/em\u003e, \u003cem\u003e40\u003c/em\u003e(3), 456–467. https://doi.org/10.1080/15374416.2011.563472\u003c/li\u003e\n \u003cli\u003eRescorla, L. A., Althoff, R. R., Ivanova, M. Y., \u0026amp; Achenbach, T. M. (2019). Effects of society and culture on parents’ ratings of children’s mental health problems in 45 societies. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e(8), 1107–1115. https://doi.org/10.1007/s00787-018-01268-3\u003c/li\u003e\n \u003cli\u003eRescorla, L., Achenbach, T. M., Ivanova, M. Y., Dumenci, L., Almqvist, F., Bilenberg, N., Bird, H., Broberg, A., Dobrean, A., Döpfner, M., Erol, N., Forns, M., Hannesdottir, H., Kanbayashi, Y., Lambert, M. C., Leung, P., Minaei, A., Mulatu, M. S., Novik, T. S., … Verhulst, F. (2007). Epidemiological comparisons of problems and positive qualities reported by adolescents in 24 countries. \u003cem\u003eJournal of Consulting and Clinical Psychology\u003c/em\u003e, \u003cem\u003e75\u003c/em\u003e(2), 351–358. https://doi.org/10.1037/0022-006X.75.2.351\u003c/li\u003e\n \u003cli\u003e*Riva, A., Nacinovich, R., Brivio, E., Mapelli, F., Rossi, S. M., Neri, F., \u0026amp; Bomba, M. (2018). Psychopathological risk in a sample of immigrant preadolescents in Italy. \u003cem\u003eMinerva Pediatrica\u003c/em\u003e, 04959–9.\u003c/li\u003e\n \u003cli\u003eRobinson, W. S. (1950). Ecological Correlations and the Behavior of Individuals. \u003cem\u003eAmerican Sociological Review\u003c/em\u003e, \u003cem\u003e15\u003c/em\u003e(3), 351–357. https://doi.org/10.2307/2087176\u003c/li\u003e\n \u003cli\u003e*Rodriguez, M. C., Wade, T. J., Veldhuizen, S., Missiuna, C., Timmons, B., \u0026amp; Cairney, J. (2019). Emotional and behavioral problems in 4-and 5-year old children with and without motor delays. \u003cem\u003eFrontiers in Pediatrics\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e, 474.\u003c/li\u003e\n \u003cli\u003eRood, L., Roelofs, J., Bögels, S. M., \u0026amp; Arntz, A. (2012). The Effects of Experimentally Induced Rumination, Positive Reappraisal, Acceptance, and Distancing When Thinking About a Stressful Event on Affect States in Adolescents. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e40\u003c/em\u003e(1), 73–84. https://doi.org/10.1007/s10802-011-9544-0\u003c/li\u003e\n \u003cli\u003e*Roussos, A., Francis, K., Zoubou, V., Kiprianos, S., Prokopiou, A., \u0026amp; Richardson, C. (2001). The standardization of Achenbach’s Youth Self-Report in Greece in a national sample of high school students. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e, 47–53.\u003c/li\u003e\n \u003cli\u003e*Roussos, A., Karantanos, G., Richardson, C., Hartman, C., Karajiannis, D., Kyprianos, S., Lazaratou, H., Mahaira, O., Tassi, M., \u0026amp; Zoubou, V. (1999). Achenbach’s Child Behavior Checklist and Teachers’ Report Form in a normative sample of Greek children 6–12 years old. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(3), 165–172.\u003c/li\u003e\n \u003cli\u003e*Rudan, V., Begovac, I., Szirovicza, L., Filipović, O., \u0026amp; Skočić, M. (2005). The child behavior checklist, teacher report form and youth self report problem scales in a normative sample of Croatian children and adolescents aged 7–18. \u003cem\u003eCollegium Antropologicum\u003c/em\u003e, \u003cem\u003e29\u003c/em\u003e(1), 17–26.\u003c/li\u003e\n \u003cli\u003eRussell, G., Kelly, S., \u0026amp; Golding, J. (2010). A qualitative analysis of lay beliefs about the aetiology and prevalence of autistic spectrum disorders. \u003cem\u003eChild: Care, Health and Development\u003c/em\u003e, \u003cem\u003e36\u003c/em\u003e(3), 431–436. https://doi.org/10.1111/j.1365-2214.2009.00994.x\u003c/li\u003e\n \u003cli\u003e*Rutherford, C., Sharp, H., Hill, J., Pickles, A., \u0026amp; Taylor-Robinson, D. (2019). How does perinatal maternal mental health explain early social inequalities in child behavioural and emotional problems? Findings from the Wirral child health and development study. \u003cem\u003ePloS One\u003c/em\u003e, \u003cem\u003e14\u003c/em\u003e(5), e0217342.\u003c/li\u003e\n \u003cli\u003eRutter, M., \u0026amp; Smith, D. J. (1997). Psychosocial disorders in young people: time trends and their cause. \u003cem\u003eBritish Journal of Educational Studies, 45(3),\u003c/em\u003e 306-336. httős://doi.org/10.1111/1467-8527.t01-1-00054\u003c/li\u003e\n \u003cli\u003eSahranavard, S., Esmaeili, A., Dastjerdi, R., \u0026amp; Salehiniya, H. (2018). The effectiveness of stress-management-based cognitive-behavioral treatments on anxiety sensitivity, positive and negative affect and hope. \u003cem\u003eBioMedicine\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(4). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6254097/\u003c/li\u003e\n \u003cli\u003e*Salum, G. A., Mogg, K., Bradley, B. P., Stringaris, A., Gadelha, A., Pan, P. M., Rohde, L. A., Polanczyk, G. V., Manfro, G. G., Pine, D. S., \u0026amp; Leibenluft, E. (2017). Association between irritability and bias in attention orienting to threat in children and adolescents. \u003cem\u003eJournal of Child Psychology and Psychiatry, and Allied Disciplines\u003c/em\u003e, \u003cem\u003e58\u003c/em\u003e(5), 595–602. https://doi.org/10.1111/jcpp.12659\u003c/li\u003e\n \u003cli\u003e*Sampasa-Kanyinga, H., Colman, I., Goldfield, G. S., Janssen, I., Wang, J., Tremblay, M. S., Barnes, J. D., Walsh, J. J., \u0026amp; Chaput, J.-P. (2021). 24-hour movement behaviors and internalizing and externalizing behaviors among youth. \u003cem\u003eJournal of Adolescent Health\u003c/em\u003e, \u003cem\u003e68\u003c/em\u003e(5), 969–977.\u003c/li\u003e\n \u003cli\u003e*Sandoval, M., Lemos, S., \u0026amp; Vallejo, G. (2006). Self-reported competences and problems in Spanish adolescents: A normative study of the YSR. \u003cem\u003ePsicothema\u003c/em\u003e, 804–809.\u003c/li\u003e\n \u003cli\u003e*Santos, I. S., Matijasevich, A., Capilheira, M. F., Anselmi, L., \u0026amp; Barros, F. C. (2015). Excessive crying at 3 months of age and behavioural problems at 4 years age: A prospective cohort study. \u003cem\u003eJournal of Epidemiology and Community Health\u003c/em\u003e, \u003cem\u003e69\u003c/em\u003e(7), 654–659. https://doi.org/10.1136/jech-2014-204568\u003c/li\u003e\n \u003cli\u003eSawhill, E. K. and I. V. (2016, September 13). How free time became screen time. \u003cem\u003eBrookings\u003c/em\u003e. https://www.brookings.edu/blog/social-mobility-memos/2016/09/13/how-free-time-became-screen-time/\u003c/li\u003e\n \u003cli\u003eSchepman, K., Collishaw, S., Gardner, F., Maughan, B., Scott, J., \u0026amp; Pickles, A. (2011). Do changes in parent mental health explain trends in youth emotional problems? \u003cem\u003eSocial Science \u0026amp; Medicine (1982)\u003c/em\u003e, \u003cem\u003e73\u003c/em\u003e(2), 293–300. https://doi.org/10.1016/j.socscimed.2011.05.015\u003c/li\u003e\n \u003cli\u003eSchiavone, N., Virta, M., Leppämäki, S., Launes, J., Vanninen, R., Tuulio-Henriksson, A., Immonen, S., Järvinen, I., Lehto, E., Michelsson, K., \u0026amp; Hokkanen, L. (2019). ADHD and subthreshold symptoms in childhood and life outcomes at 40 years in a prospective birth-risk cohort. \u003cem\u003ePsychiatry Research\u003c/em\u003e, \u003cem\u003e281\u003c/em\u003e, 112574. https://doi.org/10.1016/j.psychres.2019.112574\u003c/li\u003e\n \u003cli\u003eSchiffrin, H. H., Godfrey, H., Liss, M., \u0026amp; Erchull, M. J. (2015). Intensive parenting: Does it have the desired impact on child outcomes? \u003cem\u003eJournal of Child and Family Studies\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e, 2322–2331.\u003c/li\u003e\n \u003cli\u003eSchmuck, D. (2013). Single parenting: Fewer negative effects of children’s behaviors than claimed. \u003cem\u003eModern Psychological Studies\u003c/em\u003e, \u003cem\u003e18\u003c/em\u003e(2), 12.\u003c/li\u003e\n \u003cli\u003eSchwarzer, G. (2007). meta: An R package for meta-analysis. \u003cem\u003eR News\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e(3), 40–45.\u003c/li\u003e\n \u003cli\u003eSellers, R., Maughan, B., Pickles, A., Thapar, A., \u0026amp; Collishaw, S. (2015). Trends in parent‐ and teacher‐rated emotional, conduct and ADHD problems and their impact in prepubertal children in G reat B ritain: 1999–2008. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e56\u003c/em\u003e(1), 49–57. https://doi.org/10.1111/jcpp.12273\u003c/li\u003e\n \u003cli\u003e*Shahini, M., Rescorla, L. A., Ahmeti, A. P., Begovac, I., Dobrean, A., Markovıć, J., Rudan, V., Wancata, J., Wolanczyk, T., Zhjeqi, V., \u0026amp; Zukauskiene, R. (2015). Parent-reported behavioural and emotional problems in Albanian Kosovar children. \u003cem\u003eEpidemiology and Psychiatric Sciences\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(3), 266–273. https://doi.org/10.1017/S204579601400016X\u003c/li\u003e\n \u003cli\u003eShaikh, E. A., \u0026amp; Shinde, V. R. (2018). Gender differences in internalized and externalized behavioral problems among school going children. \u003cem\u003eIndian Journal of Health and Well-Being\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(3), 584–589.\u003c/li\u003e\n \u003cli\u003eShankman, S. A., Lewinsohn, P. M., Klein, D. N., Small, J. W., Seeley, J. R., \u0026amp; Altman, S. E. (2009). Subthreshold conditions as precursors for full syndrome disorders: A 15-year longitudinal study of multiple diagnostic classes. \u003cem\u003eJournal of Child Psychology and Psychiatry\u003c/em\u003e, \u003cem\u003e50\u003c/em\u003e(12), 1485–1494. https://doi.org/10.1111/j.1469-7610.2009.02117.x\u003c/li\u003e\n \u003cli\u003e*Shin, K. M., Cho, S.-M., Shin, Y. M., \u0026amp; Park, K. S. (2016). Effects of early childhood peer relationships on adolescent mental health: A 6-to 8-year follow-up study in South Korea. \u003cem\u003ePsychiatry Investigation\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e(4), 383.\u003c/li\u003e\n \u003cli\u003eShooshtari, S., Brownell, M., Dik, N., Chateau, D., Yu, C. T., Mills, R. S., Burchill, C. A., \u0026amp; Wetzel, M. (2014). A population-based longitudinal study of depression in children with developmental disabilities in Manitoba. \u003cem\u003eJournal of Mental Health Research in Intellectual Disabilities\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e(3), 191–207.\u003c/li\u003e\n \u003cli\u003e*Sivertsen, B., Harvey, A. G., Reichborn-Kjennerud, T., Torgersen, L., Ystrom, E., \u0026amp; Hysing, M. (2015). Later emotional and behavioral problems associated with sleep problems in toddlers: A longitudinal study. \u003cem\u003eJAMA Pediatrics\u003c/em\u003e, \u003cem\u003e169\u003c/em\u003e(6), 575–582.\u003c/li\u003e\n \u003cli\u003eSmedje, H., Broman, J.-E., Hetta, J., \u0026amp; von Knorring, A.-L. (1999). Psychometric properties of a Swedish version of the “Strengths and Difficulties Questionnaire”. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(2), 63–70. https://doi.org/10.1007/s007870050086\u003c/li\u003e\n \u003cli\u003eSondeijker, F. E., Ferdinand, R. F., Oldehinkel, A. J., Veenstra, R., Tiemeier, H., Ormel, J., \u0026amp; Verhulst, F. C. (2007). Disruptive behaviors and HPA-axis activity in young adolescent boys and girls from the general population. \u003cem\u003eJournal of Psychiatric Research\u003c/em\u003e, \u003cem\u003e41\u003c/em\u003e(7), 570–578.\u003c/li\u003e\n \u003cli\u003e*Sourander, A. (2001). Emotional and behavioural problems in a sample of Finnish three-year-olds. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(2), 98–104. https://doi.org/10.1007/s007870170032\u003c/li\u003e\n \u003cli\u003e*Sourander, A., Helstelä, L., \u0026amp; Helenius, H. (1999). Parent-adolescent agreement on emotional and behavioral problems. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e34\u003c/em\u003e, 657–663.\u003c/li\u003e\n \u003cli\u003e*Steinhausen, H.-C., Bearth-Carrari, C., \u0026amp; Winkler Metzke, C. (2009). Psychosocial adaptation of adolescent migrants in a Swiss community survey. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e44\u003c/em\u003e, 308–316.\u003c/li\u003e\n \u003cli\u003e*Steinhausen, H.-C., \u0026amp; Metzke, C. W. (2001). Risk, compensatory, vulnerability, and protective factors influencing mental health in adolescence. \u003cem\u003eJournal of Youth and Adolescence\u003c/em\u003e, \u003cem\u003e30\u003c/em\u003e(3), 259–280.\u003c/li\u003e\n \u003cli\u003e*Steinhausen, H.-C., Metzke, C. W., Meier, M., \u0026amp; Kannenberg, R. (1997). Behavioral and emotional problems reported by parents for ages 6 to 17 in a Swiss epidemiological study. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e(3), 136–141.\u003c/li\u003e\n \u003cli\u003e*Stensen, K., Stenseng, F., Lydersen, S., de Wolff, M. S., Wallander, J., \u0026amp; Drugli, M. B. (2018). Screening for mental health problems in a Norwegian preschool population. A validation of the ages and stages questionnaire: Social‐emotional (ASQ: SE). \u003cem\u003eChild and Adolescent Mental Health\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(4), 368–375.\u003c/li\u003e\n \u003cli\u003eStevanovic, D., Jafari, P., Knez, R., Franic, T., Atilola, O., Davidovic, N., Bagheri, Z., \u0026amp; Lakic, A. (2017). Can we really use available scales for child and adolescent psychopathology across cultures? A systematic review of cross-cultural measurement invariance data. \u003cem\u003eTranscultural Psychiatry\u003c/em\u003e, \u003cem\u003e54\u003c/em\u003e(1), 125–152. https://doi.org/10.1177/1363461516689215\u003c/li\u003e\n \u003cli\u003e*Stevens, G. W. J. M., Pels, T., Bengi-Arslan, L., Verhulst, F. C., Vollebergh, W. A. M., \u0026amp; Crijnen, A. A. M. (2003). Parent, teacher and self-reported problem behavior in The Netherlands: Comparing Moroccan immigrant with Dutch and with Turkish immigrant children and adolescents. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(10), 576–585. https://doi.org/10.1007/s00127-003-0677-5\u003c/li\u003e\n \u003cli\u003eSu, Q., \u0026amp; Liu, G. (2020). Birth cohort changes in the subjective well-being of Chinese college students: A cross-temporal meta-analysis, 2002–2017. \u003cem\u003eFrontiers in Psychology\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e, 1011.\u003c/li\u003e\n \u003cli\u003eSullivan, P. F., Agrawal, A., Bulik, C. M., Andreassen, O. A., Børglum, A. D., Breen, G., Cichon, S., Edenberg, H. J., Faraone, S. V., Gelernter, J., Mathews, C. A., Nievergelt, C. M., Smoller, J. W., O'Donovan, M. C., \u0026amp; Psychiatric Genomics Consortium. (2018). Psychiatric genomics: An update and an agenda. \u003cem\u003eThe American Journal of Psychiatry, 175\u003c/em\u003e(1), 15–27. https://doi.org/10.1176/appi.ajp.2017.17030283\u003c/li\u003e\n \u003cli\u003e*Tehrani-Doost, M., Shahrivar, Z., Pakbaz, B., Rezaie, A., \u0026amp; Ahmadi, F. (2011). Normative data and psychometric properties of the child behavior checklist and teacher rating form in an Iranian community sample. \u003cem\u003eIranian Journal of Pediatrics\u003c/em\u003e, \u003cem\u003e21\u003c/em\u003e(3), 331.\u003c/li\u003e\n \u003cli\u003e*Tepper, P., Liu, X., Guo, C., Zhai, J., Liu, T., \u0026amp; Li, C. (2008). Depressive symptoms in Chinese children and adolescents: Parent, teacher, and self reports. \u003cem\u003eJournal of Affective Disorders\u003c/em\u003e, \u003cem\u003e111\u003c/em\u003e(2–3), 291–298.\u003c/li\u003e\n \u003cli\u003e*Theunissen, M. H., Klein Velderman, M., Cloostermans, A. P., \u0026amp; Reijneveld, S. A. (2017). Emotional and behavioural problems in young children with divorced parents. \u003cem\u003eThe European Journal of Public Health\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(5), 840–845.\u003c/li\u003e\n \u003cli\u003eTick, N. T., Van Der Ende, J., \u0026amp; Verhulst, F. C. (2007). Twenty-year trends in emotional and behavioral problems in Dutch children in a changing society. \u003cem\u003eActa Psychiatrica Scandinavica\u003c/em\u003e, \u003cem\u003e116\u003c/em\u003e(6), 473–482.\u003c/li\u003e\n \u003cli\u003e*Tolmunen, T., Honkalampi, K., Hintikka, J., Rissanen, M.-L., Maaranen, P., Kylmä, J., \u0026amp; Laukkanen, E. (2010). Adolescent dissociation and alexithymia are distinctive but overlapping phenomena. \u003cem\u003ePsychiatry Research\u003c/em\u003e, \u003cem\u003e176\u003c/em\u003e(1), 40–44. https://doi.org/10.1016/j.psychres.2008.10.029\u003c/li\u003e\n \u003cli\u003e*Tong, L., Shi, H., \u0026amp; Li, X. (2017). Associations among ADHD, abnormal eating and overweight in a non-clinical sample of Asian children. \u003cem\u003eScientific Reports\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e(1), 2844.\u003c/li\u003e\n \u003cli\u003e*Tsotsi, S., Broekman, B. F., Shek, L. P., Tan, K. H., Chong, Y. S., Chen, H., Meaney, M. J., \u0026amp; Rifkin‐Graboi, A. E. (2019). Maternal parenting stress, child exuberance, and preschoolers’ behavior problems. \u003cem\u003eChild Development\u003c/em\u003e, \u003cem\u003e90\u003c/em\u003e(1), 136–146.\u003c/li\u003e\n \u003cli\u003eTwenge, J. M. (2020). Increases in depression, self‐harm, and suicide among US adolescents after 2012 and links to technology use: Possible mechanisms. \u003cem\u003ePsychiatric Research and Clinical Practice\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(1), 19–25.\u003c/li\u003e\n \u003cli\u003eTwenge, J. M., Joiner, T. E., Rogers, M. L., \u0026amp; Martin, G. N. (2018). Increases in depressive symptoms, suicide-related outcomes, and suicide rates among US adolescents after 2010 and links to increased new media screen time. \u003cem\u003eClinical Psychological Science\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e(1), 3–17.\u003c/li\u003e\n \u003cli\u003eTwenge, J. M., Spitzberg, B. H., \u0026amp; Campbell, W. K. (2019). Less in-person social interaction with peers among U.S. adolescents in the 21st century and links to loneliness. \u003cem\u003eJournal of Social and Personal Relationships\u003c/em\u003e, \u003cem\u003e36\u003c/em\u003e(6), 1892–1913. https://doi.org/10.1177/0265407519836170\u003c/li\u003e\n \u003cli\u003e*Uddin, M. J., Ekstrøm, C. T., Hemager, N., Christiani, C. A., Gregersen, M., Ellersgaard, D. V., Spang, K. S., Greve, A., Gantriis, D. L., \u0026amp; Burton, B. K. (2021). Is the Association Between Parents’ Mental Illness and Child Psychopathology Mediated via Home Environment and Caregiver’s Psychosocial Functioning? A Mediation Analysis of the Danish High Risk and Resilience Study—VIA7, a Population-Based Cohort Study. \u003cem\u003eSchizophrenia Bulletin Open\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(1), sgab024.\u003c/li\u003e\n \u003cli\u003e*Uljas, H., Rautava, P., Helenius, H., \u0026amp; Sillanpää, M. (1999). Behaviour of Finnish 3-year-old children. I: Effects of sociodemographic factors, mother’s health, and pregnancy outcome. \u003cem\u003eDevelopmental Medicine and Child Neurology\u003c/em\u003e, \u003cem\u003e41\u003c/em\u003e(6), 412–419. https://doi.org/10.1017/s0012162299000882\u003c/li\u003e\n \u003cli\u003eUniversities UK. (2018). \u003cem\u003eMinding our future: Starting a conversation about the support of student mental health\u003c/em\u003e. https://www.universitiesuk.ac.uk/what-we-do/policy-and-research/publications/minding-our-future-starting-conversation\u003c/li\u003e\n \u003cli\u003evan der Ende, J., Verhulst, F. C., \u0026amp; Tiemeier, H. (2012). Agreement of informants on emotional and behavioral problems from childhood to adulthood. \u003cem\u003ePsychological Assessment\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(2), 293.\u003c/li\u003e\n \u003cli\u003e*van Zeijl, J., Mesman, J., Stolk, M. N., Alink, L. R. A., van Ijzendoorn, M. H., Bakermans-Kranenburg, M. J., Juffer, F., \u0026amp; Koot, H. M. (2006). Terrible ones? Assessment of externalizing behaviors in infancy with the Child Behavior Checklist. \u003cem\u003eJournal of Child Psychology and Psychiatry, and Allied Disciplines\u003c/em\u003e, \u003cem\u003e47\u003c/em\u003e(8), 801–810. https://doi.org/10.1111/j.1469-7610.2006.01616.x\u003c/li\u003e\n \u003cli\u003e*Vásquez-Echeverría, A., Alvarez-Nuñez, L., González, M., \u0026amp; Rudnitzky, F. (2020). Behavioural problems in a nationally representative sample of Uruguay. Characterisation of latent profiles by socioeconomic status, maternal depression and family violence. \u003cem\u003eChild Psychiatry \u0026amp; Human Development\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e, 801–812.\u003c/li\u003e\n \u003cli\u003e*Vassi, I., Veltsista, A., Lagona, E., Gika, A., Kavadias, G., \u0026amp; Bakoula, C. (2008). The generation gap in numbers: Parent-child disagreement on youth’s emotional and behavioral problems: A Greek community based-survey. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e(12), 1008–1013. https://doi.org/10.1007/s00127-008-0389-y\u003c/li\u003e\n \u003cli\u003e*Veldman, K., Bültmann, U., Stewart, R. E., Ormel, J., Verhulst, F. C., \u0026amp; Reijneveld, S. A. (2014). Mental health problems and educational attainment in adolescence: 9-year follow-up of the TRAILS study. \u003cem\u003ePloS One\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(7), e101751.\u003c/li\u003e\n \u003cli\u003eVergunst, F., Tremblay, R. E., Galera, C., Nagin, D., Vitaro, F., Boivin, M., \u0026amp; Côté, S. M. (2019). Multi-rater developmental trajectories of hyperactivity–impulsivity and inattention symptoms from 1.5 to 17 years: A population-based birth cohort study. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e, 973–983.\u003c/li\u003e\n \u003cli\u003e*Verhulst, F. C., \u0026amp; Akkerhuis, G. W. (1986). Mental health in Dutch children: (III). Behavioral-emotional problems reported by teachers of children aged 4-12. \u003cem\u003eActa Psychiatrica Scandinavica. Supplementum\u003c/em\u003e, \u003cem\u003e330\u003c/em\u003e, 1–74. https://doi.org/10.1111/j.1600-0447.1986.tb10564.x\u003c/li\u003e\n \u003cli\u003e*Veríssimo, L., Dias, P., Santos, E., \u0026amp; Ortigão, S. (2020). Academic achievement and internalizing problems in primary and secondary school students in Portugal. \u003cem\u003eEducacao e Pesquisa\u003c/em\u003e, \u003cem\u003e46\u003c/em\u003e. https://doi.org/10.1590/S1678-4634202046218667\u003c/li\u003e\n \u003cli\u003e*Verlinden, M., Veenstra, R., Ghassabian, A., Jansen, P. W., Hofman, A., Jaddoe, V. W. V., Verhulst, F. C., \u0026amp; Tiemeier, H. (2014). Executive Functioning and Non-Verbal Intelligence as Predictors of Bullying in Early Elementary School. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e42\u003c/em\u003e(6), 953–966. https://doi.org/10.1007/s10802-013-9832-y\u003c/li\u003e\n \u003cli\u003eViechtebauer, W. (2021). \u003cem\u003eMetaphor package for R software.\u003c/em\u003e [Computer software]. https://www.metafor-project.org/doku.php/metafor\u003c/li\u003e\n \u003cli\u003e*Viola, L., Garrido, G., \u0026amp; Rescorla, L. (2011). Testing multicultural robustness of the Child Behavior Checklist in a national epidemiological sample in Uruguay. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(6), 897–908. https://doi.org/10.1007/s10802-011-9500-z\u003c/li\u003e\n \u003cli\u003eVuong, A. T., Jarman, H. K., Doley, J. R., \u0026amp; McLean, S. A. (2021). Social media use and body dissatisfaction in adolescents: The moderating role of thin-and muscular-ideal internalisation. \u003cem\u003eInternational Journal of Environmental Research and Public Health\u003c/em\u003e, \u003cem\u003e18\u003c/em\u003e(24), 13222.\u003c/li\u003e\n \u003cli\u003e*Waenerlund, A., Stenmark, H., Bergström, E., Hägglöf, B., Öhman, A., \u0026amp; Petersen, S. (2016). School experiences may be important determinants of mental health problems in middle childhood–a Swedish longitudinal population‐based study. \u003cem\u003eActa Paediatrica\u003c/em\u003e, \u003cem\u003e105\u003c/em\u003e(4), 407–415.\u003c/li\u003e\n \u003cli\u003e*Wang, Q. (2014). Analysis of related factors in children with behavior problems. \u003cem\u003eEnergy Education Science and Technology Part A: Energy Science and Research\u003c/em\u003e, \u003cem\u003e32\u003c/em\u003e(6), Article 6.\u003c/li\u003e\n \u003cli\u003eWatkins, E., \u0026amp; Baracaia, S. (2002). Rumination and social problem-solving in depression. \u003cem\u003eBehaviour Research and Therapy\u003c/em\u003e, \u003cem\u003e40\u003c/em\u003e(10), 1179–1189. https://doi.org/10.1016/S0005-7967(01)00098-5\u003c/li\u003e\n \u003cli\u003e*Weine, A. M., Phillips, J. S., \u0026amp; Achenbach, T. M. (1995). Behavioral and emotional problems among Chinese and American children: Parent and teacher reports for ages 6 to 13. \u003cem\u003eJournal of Abnormal Child Psychology\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(5), 619–639. https://doi.org/10.1007/BF01447666\u003c/li\u003e\n \u003cli\u003e*Weiss, B., Dang, M., Trung, L., Nguyen, M. C., Thuy, N. T. H., \u0026amp; Pollack, A. (2014). A nationally representative epidemiological and risk factor assessment of child mental health in Vietnam. \u003cem\u003eInternational Perspectives in Psychology\u003c/em\u003e, \u003cem\u003e3\u003c/em\u003e(3), 139–153.\u003c/li\u003e\n \u003cli\u003e*Wesselhoeft, R., Davidsen, K., Sibbersen, C., Kyhl, H., Talati, A., Andersen, M. S., \u0026amp; Bilenberg, N. (2021). Maternal prenatal stress and postnatal depressive symptoms: Discrepancy between mother and teacher reports of toddler psychological problems. \u003cem\u003eSocial Psychiatry and Psychiatric Epidemiology\u003c/em\u003e, \u003cem\u003e56\u003c/em\u003e(4), 559–570. https://doi.org/10.1007/s00127-020-01964-z\u003c/li\u003e\n \u003cli\u003eWhipp, A. M., Vuoksimaa, E., Bolhuis, K., de Zeeuw, E. L., Korhonen, T., Mauri, M., Pulkkinen, L., Rimfeld, K., Rose, R. J., \u0026amp; Beijsterveldt, C. (Toos) E. van. (2021). Teacher-rated aggression and co-occurring behaviors and emotional problems among schoolchildren in four population-based European cohorts. \u003cem\u003ePLoS One\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(4), e0238667.\u003c/li\u003e\n \u003cli\u003e*White, L. K., Degnan, K. A., Henderson, H. A., Pérez‐Edgar, K., Walker, O. L., Shechner, T., Leibenluft, E., Bar‐Haim, Y., Pine, D. S., \u0026amp; Fox, N. A. (2017). Developmental relations among behavioral inhibition, anxiety, and attention biases to threat and positive information. \u003cem\u003eChild Development\u003c/em\u003e, \u003cem\u003e88\u003c/em\u003e(1), 141–155.\u003c/li\u003e\n \u003cli\u003e*White, T., Muetzel, R. L., El Marroun, H., Blanken, L. M. E., Jansen, P., Bolhuis, K., Kocevska, D., Mous, S. E., Mulder, R., Jaddoe, V. W. V., van der Lugt, A., Verhulst, F. C., \u0026amp; Tiemeier, H. (2018). Paediatric population neuroimaging and the Generation R Study: The second wave. \u003cem\u003eEuropean Journal of Epidemiology\u003c/em\u003e, \u003cem\u003e33\u003c/em\u003e(1), Article 1. https://doi.org/10.1007/s10654-017-0319-y\u003c/li\u003e\n \u003cli\u003eWiggers, M., \u0026amp; Paas, F. (2022). Harsh physical discipline and externalizing behaviors in children: A systematic review. \u003cem\u003eInternational Journal of Environmental Research and Public Health\u003c/em\u003e, \u003cem\u003e19\u003c/em\u003e(21), 14385.\u003c/li\u003e\n \u003cli\u003e*Wildeboer, A., Thijssen, S., Van IJzendoorn, M. H., Van Der Ende, J., Jaddoe, V. W., Verhulst, F. C., Hofman, A., White, T., Tiemeier, H., \u0026amp; Bakermans-Kranenburg, M. J. (2015). Early childhood aggression trajectories: Associations with teacher-reported problem behaviour. \u003cem\u003eInternational Journal of Behavioral Development\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(3), 221–234.\u003c/li\u003e\n \u003cli\u003eWongupparaj, P., Wongupparaj, R., Kumari, V., \u0026amp; Morris, R. G. (2017). The Flynn effect for verbal and visuospatial short-term and working memory: A cross-temporal meta-analysis. \u003cem\u003eIntelligence\u003c/em\u003e, \u003cem\u003e64\u003c/em\u003e, 71–80.\u003c/li\u003e\n \u003cli\u003e*Wright, N., Courchesne, V., Pickles, A., Bedford, R., Duku, E., Kerns, C. M., Bennett, T., Georgiades, S., Hill, J., Richard, A., Sharp, H., Smith, I. M., Vaillancourt, T., Zaidman-Zait, A., Zwaigenbaum, L., Szatmari, P., \u0026amp; Elsabbagh, M. (2023). A longitudinal comparison of emotional, behavioral and attention problems in autistic and typically developing children. \u003cem\u003ePsychological Medicine\u003c/em\u003e, 1–13. https://doi.org/10.1017/S0033291723001599\u003c/li\u003e\n \u003cli\u003e*Wu, Y.-T., Chen, W. J., Hsieh, W.-S., Chen, P.-C., Liao, H.-F., Su, Y.-N., \u0026amp; Jeng, S.-F. (2012). Maternal-reported behavioral and emotional problems in Taiwanese preschool children. \u003cem\u003eResearch in Developmental Disabilities\u003c/em\u003e, \u003cem\u003e33\u003c/em\u003e(3), 866–873. https://doi.org/10.1016/j.ridd.2011.11.018\u003c/li\u003e\n \u003cli\u003e*Xerxa, Y., Rescorla, L. A., Serdarevic, F., Van IJzendorn, M. H., Jaddoe, V. W., Verhulst, F. C., Luijk, M. P., \u0026amp; Tiemeier, H. (2020). The complex role of parental separation in the association between family conflict and child problem behavior. \u003cem\u003eJournal of Clinical Child \u0026amp; Adolescent Psychology\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(1), 79–93.\u003c/li\u003e\n \u003cli\u003e*Xue, Y., Leventhal, T., Brooks-Gunn, J., \u0026amp; Earls, F. J. (2005). Neighborhood residence and mental health problems of 5-to 11-year-olds. \u003cem\u003eArchives of General Psychiatry\u003c/em\u003e, \u003cem\u003e62\u003c/em\u003e(5), 554–563.\u003c/li\u003e\n \u003cli\u003e*Yang, H.-J., Soong, W.-T., Chiang, C.-N., \u0026amp; Chen, W. J. (2000). Competence and behavioral/emotional problems among Taiwanese adolescents as reported by parents and teachers. \u003cem\u003eJournal of the American Academy of Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(2), 232–239.\u003c/li\u003e\n \u003cli\u003eYang, Y., Cao, S., Shields, G. S., Teng, Z., \u0026amp; Liu, Y. (2017). The relationships between rumination and core executive functions: A meta-analysis. \u003cem\u003eDepression and Anxiety\u003c/em\u003e, \u003cem\u003e34\u003c/em\u003e(1), 37–50. https://doi.org/10.1002/da.22539\u003c/li\u003e\n \u003cli\u003eYazdani, M., Rezaei, S., \u0026amp; Pahlavanzadeh, S. (2010). The effectiveness of stress management training program on depression, anxiety and stress of the nursing students. \u003cem\u003eIranian Journal of Nursing and Midwifery Research\u003c/em\u003e, \u003cem\u003e15\u003c/em\u003e(4), 208.\u003c/li\u003e\n \u003cli\u003e*Yunis, F., Eapen, V., Zoubeidi, T., \u0026amp; Yousef, S. (2007). Psychometric properties of the Child Behavior Checklist/2-3 in an Arab population. \u003cem\u003ePsychological Reports\u003c/em\u003e, \u003cem\u003e100\u003c/em\u003e(3 Pt 1), 771–776. https://doi.org/10.2466/pr0.100.3.771-776\u003c/li\u003e\n \u003cli\u003eZalewski, M., Lengua, L. J., Fisher, P. A., Trancik, A., Bush, N. R., \u0026amp; Meltzoff, A. N. (2012). Poverty and single parenting: Relations with preschoolers’ cortisol and effortful control. \u003cem\u003eInfant and Child Development\u003c/em\u003e, \u003cem\u003e21\u003c/em\u003e(5), 537–554.\u003c/li\u003e\n \u003cli\u003e*Zandstra, A. R. E., Ormel, J., Dietrich, A., van den Heuvel, E. R., Hoekstra, P. J., \u0026amp; Hartman, C. A. (2018). Sensitivity to psychosocial chronic stressors and adolescents’ externalizing problems: Combined moderator effects of resting heart rate and parental psychiatric history. \u003cem\u003eBiological Psychology\u003c/em\u003e, \u003cem\u003e134\u003c/em\u003e, 20–29.\u003c/li\u003e\n \u003cli\u003eZerwas, S., Holle, A. V., Watson, H., Gottfredson, N., \u0026amp; Bulik, C. M. (2014). Childhood anxiety trajectories and adolescent disordered eating: Findings from the NICHD study of early child care and youth development. \u003cem\u003eInternational Journal of Eating Disorders\u003c/em\u003e, \u003cem\u003e47\u003c/em\u003e(7), 784–792.\u003c/li\u003e\n \u003cli\u003eZhao, M. Z., Song, X. S., \u0026amp; Ma, J. S. (2021). Gene× environment interaction in major depressive disorder. \u003cem\u003eWorld Journal of Clinical Cases\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(31), 9368.\u003c/li\u003e\n \u003cli\u003eZhao, Z., Wan, R., \u0026amp; Ma, J. (2022). Social change and birth cohorts decreased resilience among college students in China: A cross-temporal meta-analysis, 2007–2020. \u003cem\u003ePersonality and Individual Differences\u003c/em\u003e, \u003cem\u003e196\u003c/em\u003e, 111716.\u003c/li\u003e\n \u003cli\u003eZheng, H., \u0026amp; Echave, P. (2021). Are recent cohorts getting worse? Trends in US adult physiological status, mental health, and health behaviors across a century of birth cohorts. \u003cem\u003eAmerican Journal of Epidemiology\u003c/em\u003e, \u003cem\u003e190\u003c/em\u003e(11), 2242-2255.\u003c/li\u003e\n \u003cli\u003eZhong, Q., Niu, L., Chen, K., Lee, T. M. C., \u0026amp; Zhang, R. (2024). Prevalence and risk of subthreshold anxiety developing into threshold anxiety disorder in the general population. \u003cem\u003eJournal of Affective Disorders\u003c/em\u003e, \u003cem\u003e367\u003c/em\u003e, 815–822. https://doi.org/10.1016/j.jad.2024.09.031\u003c/li\u003e\n \u003cli\u003e*Zhu, Z., Shen, J., Zhu, Y., Wang, L., Qi, Q., Wang, X., Li, C., Andegiorgish, A. K., Elhoumed, M., Cheng, Y., Dibley, M. J., \u0026amp; Zeng, L. (2022). Head circumference trajectories during the first two years of life and cognitive development, emotional, and behavior problems in adolescence: A cohort study. \u003cem\u003eEuropean Journal of Pediatrics\u003c/em\u003e, \u003cem\u003e181\u003c/em\u003e(9), 3401–3411. https://doi.org/10.1007/s00431-022-04554-0\u003c/li\u003e\n \u003cli\u003eZoellner, F., Erhart, M., Napp, A. K., Reiss, F., Devine, J., Kaman, A., \u0026amp; Ravens-Sieberer, U. (2024). Risk and protective factors for mental health problems in children and adolescents during the COVID-19 pandemic: results of the longitudinal COPSY study. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, 1-11.\u003c/li\u003e\n \u003cli\u003e*Zondervan‐Zwijnenburg, M. A., Veldkamp, S. A., Neumann, A., Barzeva, S. A., Nelemans, S. A., van Beijsterveldt, C. E., Branje, S. J., Hillegers, M. H., Meeus, W. H., \u0026amp; Tiemeier, H. (2020). Parental age and offspring childhood mental health: A multi‐cohort, population‐based investigation. \u003cem\u003eChild Development\u003c/em\u003e, \u003cem\u003e91\u003c/em\u003e(3), 964–982.\u003c/li\u003e\n \u003cli\u003e*Zubeidat, I., Dallasheh, W., Fernández-Parra, A., Sierra, J. C., \u0026amp; Salinas, J. M. (2018). Youth self-report factor structure: Detecting sex and age differences in emotional and behavioral problems among Spanish school adolescent sample. \u003cem\u003eInt’l J. Soc. Sci. Stud.\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e, 35.\u003c/li\u003e\n \u003cli\u003e*Zukauskiene, R., Ignataviciene, K., \u0026amp; Daukantaité, D. (2003). Subscales scores of the Lithuanian version of CBCL. \u003cem\u003eEuropean Child \u0026amp; Adolescent Psychiatry\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(3), 136–143.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"emotional problems, behavioral problems, trends, youth","lastPublishedDoi":"10.21203/rs.3.rs-7905820/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7905820/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThere is a general conception that mental health problems are increasing in younger generations, though little objective comparisons exist. The current meta-analysis examined changes in subclinical mean-level emotional and behavioral problems among population-based samples of youth (1-18 years) globally over the last four decades. We searched systematically in PubMed, Web of Science, Scopus, EBSCO and Google Scholar with pre-registered criteria [removed for masked review]. Included studies (\u003cem\u003ek\u003c/em\u003e = 175, \u003cem\u003eN\u003c/em\u003e = 418,528) used the standardized and cross-culturally validated Child Behavior Checklist with parents, teachers and self-reports. A cross-temporal meta-analysis was conducted with data points between 1981 to 2019. Age, sex, response rate, continent were used as moderators. Meta-regression analyses, with year of data collection as predictor, showed that total emotional and behavioral problems did not change in the past 40 years. However, there was evidence of change in specific problems. We find strong evidence for decreased aggression in children over time (parent report: \u003cem\u003ek\u003c/em\u003e = 47, \u003cem\u003eb\u003c/em\u003eyear = -0.18, \u003cem\u003ep\u003c/em\u003e = .009, 95%CI[-0.31,-0.05]; self-report: \u003cem\u003ek\u003c/em\u003e = 9, \u003cem\u003eb\u003c/em\u003eyear = -0.41, \u003cem\u003ep\u003c/em\u003e = .006, 95%CI[-0.66,-0.16]). There was evidence of a decrease in parent reported externalizing problems in middle childhood (\u003cem\u003ek\u003c/em\u003e = 60, \u003cem\u003eb\u003c/em\u003eyear = -0.21, \u003cem\u003ep\u003c/em\u003e \u0026lt; .001, 95%CI[-0.30,-0.11]) and specifically in teenage boys (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = -0.27, \u003cem\u003ep\u003c/em\u003e = .049, 95%CI[-0.54,0]). In contrast, there were increases in parent-reported attention (\u003cem\u003ek\u003c/em\u003e = 63, \u003cem\u003eb\u003c/em\u003eyear= 0.24, \u003cem\u003ep\u003c/em\u003e = .004, 95%CI[0.08,0.40]) and thought problems (\u003cem\u003ek\u003c/em\u003e = 40, \u003cem\u003eb\u003c/em\u003eyear= 0.09, \u003cem\u003ep\u003c/em\u003e = .006, 95%CI[0.03,0.15]) for youth overall, and anxiety-depression symptoms specifically in teens (\u003cem\u003ek\u003c/em\u003e = 12, \u003cem\u003eb\u003c/em\u003eyear = 0.26, \u003cem\u003ep\u003c/em\u003e = .011, 95%CI[0.07,0.45]), although with high heterogeneity. In sum, our results do not support concerns that children and young people today experience more emotional and behavioural problems than previous generations, rather, they experience subtly different patterns of difficulties. However, an important limitation of the study is that post COVID-19 changes were not studied.\u003c/p\u003e","manuscriptTitle":"Kids These Days! A Cross-Temporal Meta-Analysis of Changes in Emotional and Behavioral Problems of Population-Based Samples Over the Past Decades","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-11 09:48:44","doi":"10.21203/rs.3.rs-7905820/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bee25bed-03bd-4107-ad7c-2acc2235c7b2","owner":[],"postedDate":"December 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-19T09:42:31+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-11 09:48:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7905820","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7905820","identity":"rs-7905820","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}