Emotion regulation mediates the effect of insomnia on non-suicidal self-injury in adolescents: The moderating role of mindfulness

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This study aims to investigate the association between insomnia and NSSI, focusing on the mediating role of emotion regulation and the moderating effect of mindfulness. Methods A cross-sectional survey was conducted among 4,259 students at a vocational and technical school in China. Participants were stratified into two groups based on the presence or absence of NSSI behaviors within the past year. Demographic data and standardized assessments were collected, including the Insomnia Severity Index (ISI), Difficulties in Emotion Regulation Scale (DERS), Mindful Attention Awareness Scale (MAAS), and the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire (ANSAQ). Structural equation modeling (SEM) was used to test hypothesized relationships. Results Among the participants, 34.7% (n = 1,402) reported NSSI in the past year. Those with NSSI showed significantly higher insomnia severity, greater emotion dysregulation, and lower mindfulness (all p s < 0.01). Insomnia was indirectly associated with NSSI through increased emotion regulation difficulties ( p < 0.01). Mindfulness moderated this pathway, attenuating the impact of insomnia on both emotion dysregulation and subsequent NSSI (both p s < 0.01). Conclusions Insomnia increases NSSI risk by impairing emotion regulation, while mindfulness mitigates this effect. These findings highlight key psychological mechanisms and support mindfulness-based approaches in NSSI prevention, particularly for adolescents with low trait mindfulness. non-suicidal self-injury mindfulness insomnia emotion regulation structural equation model Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Non-suicidal self-injury (NSSI), defined as the intentional, direct harm to one’s own body tissue without suicidal intent (Nock 2010 ), includes behaviors such as cutting, burning, hitting, or scratching. Among adolescents, NSSI has become a significant public health challenge. A recent meta-analysis estimated the prevalence of NSSI among Chinese adolescents at 22.4% (McEvoy, Brannigan et al. 2023). This behavior is consistently linked to emotional dysregulation (Hornor 2016 ), underscoring its clinical importance and the urgent need for targeted interventions. Despite growing awareness, prevention and intervention efforts remain limited, particularly within the domestic context. Clarifying the psychological mechanisms underlying NSSI is essential to inform evidence-based strategies and reduce its prevalence (Brown and Plener 2017 ). One emerging contributor to NSSI is insomnia, a condition characterized by persistent difficulties in initiating or maintaining sleep, or early morning awakenings (Morin, Drake et al. 2015). A growing body of evidence links insomnia to increased risk of NSSI (Chen, Gong et al. 2025), particularly among adolescents. This relationship is especially pronounced when emotional regulation capacities are compromised (Yang and Zhao 2024 ). Insomnia can heighten emotional reactivity and reduce coping capacity, making self-injury a more likely response to negative affect(Hysing, Sivertsen et al. 2015). Conversely, NSSI may further disrupt sleep through physical discomfort and psychological distress, suggesting a bidirectional relationship (Yang and Zhao 2024 ). This association appears strongest among adolescents with poor emotion regulation, pointing to a potentially modifiable mediating mechanism. Emotion regulation, the ability to monitor, evaluate, and modify emotional responses, has been proposed as a key psychological link between insomnia and behavioral outcomes such as NSSI(Latina, Bauducco et al. 2021). Individuals with insomnia often exhibit diminished emotional awareness, poor cognitive flexibility, and greater reliance on maladaptive regulation strategies (Ballesio, Aquino et al. 2019). NSSI, in turn, is frequently used as a maladaptive but temporarily effective strategy to relieve acute negative emotional states (Zetterqvist, Lundh et al. 2013). These overlapping features suggest that emotion regulation difficulties may represent a central pathway through which insomnia contributes to self-injurious behavior (Bauducco, Tilton-Weaver et al. 2025), offering a potential for clinical intervention. Mindfulness, the practice of nonjudgmental awareness of the present moment (Keng, Smoski et al. 2011), has received increasing attention for its protective role in adolescent mental health (Creswell 2017 ). It has been shown to promote adaptive emotion regulation by enhancing emotional clarity, reducing cognitive reactivity, and curbing maladaptive processes such as rumination and impulsivity (Khoury, Lecomte et al. 2013). These mechanisms may lower the risk of NSSI, particularly among individuals with emotion regulation difficulties (Per, Simundic et al. 2022). Furthermore, mindfulness may buffer the emotional consequences of insomnia, attenuating its impact on stress reactivity and maladaptive coping behaviors (Rusch, Rosario et al. 2019). However, the moderating role of mindfulness in the insomnia–emotion regulation–NSSI pathway has yet to be systematically examined in adolescent populations, who are particularly vulnerable to both sleep disturbances and emotional dysregulation. To our knowledge, no prior study has simultaneously examined both the mediating role of emotion regulation and the moderating role of mindfulness in the link between insomnia and NSSI among adolescents. The present study investigates the interrelationships among insomnia, emotion regulation, mindfulness, and NSSI in a large adolescent sample. Using structural equation modeling (SEM), we test a moderated mediation model to examine: 1) whether emotion regulation mediates the association between insomnia and NSSI; 2) whether mindfulness moderates this indirect pathway; and 3) whether different components of emotion regulation contribute differentially to this relationship. Methods 2.1 Study setting and participants This cross-sectional study was conducted at Huajian Technology Vocational School in Ganzhou City, China. A total of 4,259 students were invited to participate in a school-wide survey assessing sleep behavior, emotion regulation, mindfulness, and self-injurious behaviors. Data were collected through a supervised, self-administered paper-and-pencil questionnaire completed in classroom settings. After rigorous data screening to exclude incomplete or logically inconsistent responses, 4,040 valid cases were retained for analysis, yielding a high response rate. Participants ranged in age from 13 to 21 years (M = 16.06, SD = 0.92), with 59% identifying as female. Written informed consent was obtained from all participants, with parental consent additionally secured for minors. Ethical approval was obtained from the Institutional Review Board of Tianjin Anding Hospital. 2.2 Measures 2.2.1 Insomnia Insomnia symptoms were assessed using the Insomnia Severity Index (ISI), a 7-item self-report measure developed to evaluate perceived sleep difficulties over the past two weeks (Rosch 1994 ). Items cover domains such as sleep onset and maintenance, satisfaction with sleep, interference with daytime functioning, and sleep-related distress. Responses are rated on a 5-point Likert scale (0 = “no problem” to 4 = “very severe problem”), yielding a total score ranging from 0 to 28. Standard clinical cutoffs categorize scores into no insomnia (0–7), subthreshold insomnia (8–14), moderate insomnia (15–21), and severe insomnia (22–28) (Bastien 2001). The ISI has demonstrated strong psychometric properties across diverse populations (Manzar, Jahrami et al. 2021). In this sample, internal consistency was excellent (Cronbach’s α = 0.94). 2.2.2 Emotion regulation Emotion regulation difficulties were measured using the Difficulties in Emotion Regulation Scale (DERS), a 36-item self-report instrument assessing problems in six domains: nonacceptance of emotions, difficulty engaging in goal-directed behavior, impulse control difficulties, lack of emotional awareness, limited access to regulation strategies, and lack of emotional clarity (Gratz and Roemer 2004 ). Items are rated on a 5-point Likert scale (1 = “almost never” to 5 = “almost always”). Eleven items are reverse-scored to maintain consistency in direction. Total scores range from 36 to 180, with higher scores indicating greater emotion dysregulation. Previous studies have shown strong psychometric properties, including internal consistency (α = 0.93–0.96) and test-retest reliability (ICC = 0.88). In the current study, internal consistency was excellent for the total score (α = 0.94) and ranged from 0.81 to 0.92 across subscales. 2.2.3 Mindfulness assessment Trait mindfulness was assessed using the Chinese version of the Mindful Attention Awareness Scale (MAAS) (Brown and Ryan 2003 , Deng, Li et al. 2012). The MAAS consists of 15 items measuring attention to and awareness of present-moment experiences. Items are rated on a 6-point Likert scale ranging from 1 (“almost always”) to 6 (“almost never”), with higher mean scores reflecting greater mindfulness. The MAAS has shown high internal consistency in Chinese adolescent samples (α = 0.89–0.93) (Black, Sussman et al. 2012). In this study, internal consistency was strong (Cronbach’s α = 0.89). 2.2.4 NSSI NSSI was measured using the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire (ANSAQ), a validated self-report tool developed to assess both behavioral frequency and functional motivations for NSSI in adolescents (Whitlock, Exner-Cortens et al. 2014). The behavioral section consists of 12 items assessing NSSI behaviors over the past 12 months, categorized into behaviors without significant tissue damage (7 items, e.g., scratching, hair pulling) and those with evident tissue damage (5 items, e.g., cutting, burning). A total behavioral frequency score is computed by summing item responses. The functional section includes subscales assessing intrapersonal and interpersonal functions of NSSI. The ANSAQ has demonstrated robust psychometric properties: behavioral subscale internal consistency (α = 0.921), split-half reliability (r = 0.851), and test–retest reliability (r = 0.843). The functional component also showed satisfactory internal consistency (α = 0.813). In this study, internal consistency was comparable, supporting its use in this population. 2.3 Statistical analysis All statistical analyses were conducted using SPSS version 27 (IBM Corp., Armonk, NY) and Mplus version 8.3 (Muthén & Muthén, Los Angeles, CA). The analysis followed a multi-step approach to examine the associations among insomnia, emotion regulation, mindfulness, and NSSI. Descriptive statistics and bivariate correlations were computed for all study variables. The Kolmogorov–Smirnov test was used to assess the normality of continuous variable distributions. For variables that did not meet normality assumptions, non-parametric tests were employed: Mann–Whitney U tests for two-group comparisons and Kruskal–Wallis H tests for comparisons involving more than two groups. Categorical variables were analyzed using Pearson’s chi-square test. Continuous variables are reported as mean (standard deviation, SD) or median (interquartile range, IQR), depending on distributional characteristics. Statistical significance was set at two-tailed p < 0.05. Group differences in emotion regulation between adolescents with and without NSSI were tested using independent-samples t-tests. Welch’s correction was applied when homogeneity of variance was violated. To control for Type I error across the DERS total score and its six subscales, p-values were adjusted using the Benjamini–Hochberg false discovery rate (FDR), targeting a 5% false discovery rate. Effect sizes were calculated using Hedges’ g, with 95% confidence intervals (CIs) reported to aid interpretation. To test our core hypotheses, we estimated an observed-variable moderated mediation model in Mplus (Muller, Judd et al. 2005). Insomnia was specified as the predictor, emotion regulation as the mediator, mindfulness as the moderator, and NSSI as the outcome. An interaction term (emotion regulation × mindfulness) was computed using mean-centered variables and included in the model to test for conditional effects. This model included two regression paths: (1) the mediator (emotion regulation) was regressed on the predictor (insomnia) and moderator (mindfulness); (2) the outcome (NSSI) was regressed on the predictor, mediator, and the mediator×moderator interaction. Parameter estimation used full information maximum likelihood (FIML), which allows for robust handling of missing data under the assumption of missing at random (MAR). Indirect effects were tested using 5,000 bias-corrected bootstrap resamples. Statistical significance was determined by whether the 95% bootstrap confidence interval excluded zero To interpret the interaction between emotion regulation and mindfulness, simple slope analyses were conducted (Montoya 2019 ). Conditional effects of emotion dysregulation on NSSI were estimated at three levels of mindfulness: one standard deviation below the mean (low), at the mean (moderate), and one standard deviation above the mean (high). This approach enabled a nuanced interpretation of how trait mindfulness moderates the impact of emotional dysregulation on NSSI. Given that we specified an observed-variable model including a product interaction term, conventional structural equation modeling fit indices (e.g., CFI, TLI, RMSEA) were not reported. Instead, model adequacy was evaluated using information-theoretic indices: the Akaike Information Criterion (AIC) (Akaike 1974 ) and Bayesian Information Criterion (BIC) (Schwarz 1978 ). These criteria are well-suited for model selection in complex behavioral datasets, balancing model fit against parsimony; lower values indicate a better trade-off. Model convergence and numerical integration diagnostics were inspected to ensure stability and computational validity (Heinze, Wallisch et al. 2018, Dziak, Coffman et al. 2020). Results 3.1 Baseline characteristics of adolescents and correlations between variables Figure 1 presents the distribution of and bivariate correlations among key study variables. The kernel density plots revealed that, compared to the Non-NSSI group, the NSSI group demonstrated a shift towards higher scores on the ISI and DERS, and lower scores on the MAAS. The correlation patterns were consistent across groups but stronger in the NSSI group. Insomnia severity was negatively correlated with mindfulness (Non-NSSI: r = -0.49; NSSI: r = -0.55) and positively correlated with emotion dysregulation (Non-NSSI: r = 0.40; NSSI: r = 0.47). Mindfulness was negatively correlated with emotion dysregulation in both groups (Non-NSSI: r = -0.54; NSSI: r = -0.58). Furthermore, Fig. 2 shows that in the NSSI group, the total NSSI-behavior score was positively correlated with insomnia severity (r = 0.28) and emotion dysregulation (r = 0.31), and negatively correlated with mindfulness (r = -0.33). 3.2 Psychological Profiles Differentiate NSSI and Non-NSSI Groups Table 2 presents significant differences emerged across all psychological measures between the NSSI and Non-NSSI groups. Participants with NSSI reported substantially higher insomnia severity compared to non-self-injuring individuals (Cohen’s d = 0.71, p < 0.001). Similarly, the NSSI group demonstrated markedly lower mindfulness (p < 0.001). For DERS, the NSSI cohort scored significantly higher on all subscales and the total score (p < 0.001 for all comparisons). Largest effects were observed for impulse control difficulties (d = 0.81; NSSI M = 9.75, SD = 5.25 ; non-NSSI M = 6.07, SD = 4.01) and limited emotion regulation strategies (d = 0.84; NSSI M = 15.83, SD = 6.92 ; non-NSSI M = 10.64, SD = 5.36). Notably, lack of emotional awareness showed a reversed scoring pattern yet remained significantly elevated in the NSSI group (d = 0.27, p < 0.001). All DERS findings retained significance after false discovery rate correction (p-FDR < .001 across 7 comparisons). Table 1 presents the demographic characteristics of the study participants. Among 4,040 adolescents, 1,402 (34.70%) reported NSSI and 2,638 did not. Age differed slightly between groups (p = 0.005), a statistically significant but trivial difference (SMD = 0.02). Sex distribution was comparable (p = 0.307). Only-child status was similar (p = 0.614). Numerically fewer adolescents with NSSI lived with parents, but the difference was not statistically significant (p = 0.080). Study group, mean (SD), n (%) Variables NSSI (n = 1402) Non-NSSI (n = 2638) F/Z/χ2 p -value Age 16.06(0.93) 16.08(0.91) -2.819 0.005 Sex Female 730(52.07%) 1329(50.40%) 1.046 0.307 Male 672(47.93%) 1309(49.60%) a Only-child status Yes 79 (5.63%) 159 (6.03%) 0.254 0.614 No 1323 (94.37%) 2479 (93.97%) b Living style Living with parents 670 (47.79%) 1337 (50.68%) 3.066 0.08 Others 732 (52.21%) 1301 (49.32%) Descriptive Characteristics of Self-Injury in the Past Year Table 2 Comparisons of ISI, MAAS, and DERS scores between the non-NSSI and NSSI groups Study group, mean (SD) Variable NSSI Non-NSSI p-value Cohen’s d (95% CI) ISI-Total 9.31 (5.58) 5.70 (4.60) < 0.001 0.73 [0.660, 0.793] MAAS-Total 58.82 (12.74) 68.27 (11.79) < 0.001 −0.78 [− 0.85, − 0.71] Nonacceptance 14.59 (5.17) 11.13 (4.22) < 0.001 0.76 [0.69, 0.83] Goals 9.50 (4.29) 6.81 (3.70) < 0.001 0.69 [0.62, 0.75] Impulse 9.75 (5.25) 6.07 (4.01) < 0.001 0.82 [0.75, 0.89] Awareness -16.57 (4.53) -15.35 (4.61) < 0.001 −0.27 [− 0.33, − 0.20] Strategies 15.83 (6.92) 10.64 (5.36) < 0.001 0.87 [0.80, 0.94] Clarity 1.04 (3.03) -0.36 (2.76) < 0.001 0.49 [0.42, 0.56] DERS-Total 34.14 (19.56) 18.94 (15.81) < 0.001 pFDR < .001 0.88 [0.82, 0.95] Note: NSSI, non-suicidal self-injury, refers to Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire scores; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale; Nonacceptance, nonacceptance of emotional responses; Goals, difficulties engaging in goal-directed behavior; Impulse, impulse control difficulties; Awareness, lack of emotional awareness; Strategies, limited access to emotion regulation strategies; Clarity, lack of emotional clarity. p(FDR) values were adjusted for multiple testing using the Benjamini–Hochberg false discovery rate (FDR) procedure across m = 7 comparisons (DERS total scores and six subscales). 3.3 The moderated mediating model Figure 3 presents a moderated mediation model tested with 5,000 bootstrap samples on NSSI groups using maximum likelihood estimation. We compared an interaction model with a reduced model omitting the interaction. Likelihood-based information criteria favored the interaction specification (AIC = 20,637.99; BIC = 20,685.19; sample-size adjusted BIC = 20,656.60) over the reduced model (AIC = 20,672.15; BIC = 20,714.11; adjusted BIC = 20,688.70); ΔBIC = 29.00 indicates very strong evidence for the interaction model. A likelihood-ratio test corroborated this improvement (p < .001). The model showed acceptable fit. The independent variable insomnia significantly predicted the mediator (difficulties in emotion regulation; β = 0.220, p < 0.001), while the moderator mindfulness negatively predicted mediator (β = -0.456, p < 0.001). In the outcome model, insomnia (β = 0.117, p < 0.001), difficulties in emotion regulation (β = 0.228, p < 0.001), and the interaction term (β = -0.269, p = 0.001) were all significant predictors of NSSI, indicating both mediation and moderation effects. The average indirect effect was significant (Indirect effect = 0.176, 95% bootstrap CI [0.115, 0.248]), supporting a mediation mechanism. Figure 4 shows the strength of the mediation effect at different levels of mindfulness as the moderator. In the NSSI group, the indirect effects were significant at the mean and ± 1 SD of MAAS scores in the NSSI group, with a smaller effect at high mindfulness (Indirect = 0.155, 95% CI [0.105, 0.213]) and a larger effect at low mindfulness (Indirect = 0.198, 95% CI [0.125, 0.284]), suggesting that mindfulness moderated the strength of the mediation effect. Discussion To our knowledge, this is the first study to simultaneously examine the mediating role of emotion regulation and the moderating role of mindfulness in the relationship between insomnia and NSSI among adolescents. The findings provide novel insight into how psychological vulnerabilities and protective factors interact to influence self-injurious behavior in this population. First, adolescents who engaged in NSSI reported significantly greater insomnia severity, more pronounced emotion regulation difficulties, and lower levels of mindfulness compared to their peers without NSSI. Second, insomnia was indirectly associated with increased risk of NSSI through its impact on emotion regulation, supporting the hypothesis that sleep disturbances may heighten emotional dysregulation, thereby increasing vulnerability to self-injury. Third, mindfulness significantly attenuated this indirect effect: adolescents with higher levels of mindfulness showed a weaker link between insomnia and emotion dysregulation, which in turn reduced the likelihood of NSSI. These findings highlight the dual role of emotion regulation as a risk mechanism and mindfulness as a resilience factor, underscoring their relevance as potential targets for prevention and early intervention efforts. We observed a 12-month NSSI prevalence of 34.7% among Chinese vocational high school students, substantially higher than previously reported estimates (McEvoy, Brannigan et al. 2023). Several factors may account for this elevated rate. First, NSSI tends to peak during mid-adolescence, when emotional regulation systems are still maturing and individuals face increasing academic and interpersonal stressors. Prior research has shown that adolescents in East Asian contexts may report particularly high NSSI prevalence due to the unique sociocultural pressures associated with education and family expectations (Farkas, Takacs et al. 2024) (Plener, Allroggen et al. 2016). Second, our sample, drawn from a vocational school, may reflect a subgroup with distinct academic and psychosocial vulnerabilities that heighten NSSI risk. Interestingly, living arrangements (i.e., whether adolescents lived with their family members) were not significantly associated with NSSI risk. This may be due to the operationalization of “lifestyle” as a structural variable (e.g., co-residence with parents), rather than capturing the quality of family functioning. Previous research has demonstrated that emotional family climate, characterized by support, warmth, or conflict, is a more robust predictor of adolescent psychological outcomes than structural family variables alone (Gratz and Roemer 2004 ). Within collectivistic cultures such as China’s, adolescents may be particularly influenced by the emotional dynamics of their family system (Zhou, Kyeong et al. 2022), which should be better captured in future research. Consistent with prior work, we found that adolescents who engaged in NSSI reported significantly higher difficulties across all six subdomains of emotion regulation. This aligns with neurobiological models suggesting impaired top-down regulatory control, including amygdala hyper-reactivity and weakened prefrontal cortical modulation of negative affect (Westlund Schreiner, Klimes-Dougan et al. 2017). Emotionally dysregulated youth may be more likely to rely on maladaptive coping strategies, such as suppression or rumination, which further reinforce emotional distress and increase vulnerability to self-injury (Gratz and Roemer 2004 ). These findings reinforce emotion regulation as a central transdiagnostic mechanism and a potential therapeutic target. Adolescents with a recent history of NSSI also exhibited significantly lower levels of trait mindfulness compared to their non-NSSI peers. This is in line with studies showing that mindfulness enhances attentional control, reduces automatic reactivity to distressing stimuli, and fosters decentering from negative thoughts (Marchand 2014 , Guendelman, Medeiros et al. 2017). More importantly, our moderated mediation model demonstrated that mindfulness significantly buffered the indirect effect of insomnia on NSSI via emotion regulation. That is, adolescents with higher levels of mindfulness showed less emotion dysregulation in response to insomnia symptoms, which in turn reduced their likelihood of engaging in NSSI. This finding is consistent with meta-analytic evidence supporting the efficacy of mindfulness-based interventions in enhancing emotional resilience(Khoury et al., 2013 ) (Guendelman, Medeiros et al. 2017), which may indirectly reduce vulnerability to maladaptive behaviors such as NSSI. Randomized trials have further shown that even brief mindfulness-based interventions can improve regulatory capacity and reduce NSSI risk (Zheng, Chen et al. 2025 ). Our findings also confirmed that adolescents with NSSI reported significantly greater insomnia symptoms. This is consistent with evidence suggesting that insomnia contributes to persistent hyperarousal, potentially driven by dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, which impairs both sleep onset and continuity (Reichl, Heyer et al. 2016). Experimental studies show that sleep deprivation impairs prefrontal inhibitory control and increases impulsivity and risk-taking, particularly during nocturnal or fatigue states—factors that may facilitate self-injurious behaviors (Leone, Kuja-Halkola et al. 2023). Our data also support the proposed mechanistic link between sleep disturbance and emotion regulation: insomnia predicted increased emotion dysregulation, which in turn elevated NSSI risk. This may reflect sleep-related disruption of prefrontal–amygdala connectivity, which diminishes top-down modulation of negative affect and heightens emotional intensity (Yoo, Gujar et al. 2007)(Yoo, Gujar et al. 2007). Moreover, the results indicated that mindfulness capacity could play a moderating role within this pathway. Consistent with previous accounts, meta-analytic evidence shows that mindfulness-based interventions improve regulatory capacities and psychiatric outcomes, suggesting modifiability of the pathway’s strength (Khoury, Lecomte et al. 2013). Neurocognitive models highlight that mindfulness strengthens top-down attentional regulation, promotes decentering from distressing thoughts, and facilitates flexible emotional responding, thereby reducing reliance on maladaptive strategies (Guendelman, Medeiros et al. 2017). Mindfulness-based interventions could be effective in reducing NSSI behaviors, offering a practical avenue for supporting adolescents experiencing insomnia-related emotional challenges. Several limitations should be acknowledged. First, the cross-sectional design precludes causal inference; longitudinal and experimental designs are needed to clarify the temporal directionality among insomnia, emotion regulation, and NSSI. Second, the sample was drawn from a single vocational school in China, which may limit the generalizability of findings to other adolescent populations. Third, all variables were assessed via self-report, which may be subject to recall bias or social desirability effects. Finally, while we included several key psychological constructs, we did not assess potential confounders such as trauma history, peer victimization, or detailed family functioning, all of which may influence both sleep and self-injurious behaviors. Conclusions This study reveals that insomnia contributes to adolescent NSSI through emotion regulation difficulties, with mindfulness acting as a protective moderator. These findings highlight the importance of addressing sleep problems and emotional vulnerability in youth, while also supporting the use of mindfulness-based strategies in prevention efforts. Targeting these modifiable factors may offer effective pathways for reducing self-injurious behaviors among at-risk adolescents. Declarations Funding This work was supported by Ministry of Education, Humanities and Social Sciences Youth Fund (23YJCZH106). All funding had no role in study design, data analysis, article submission and publication. Authors' contribution All authors have contributed to and have approved the final manuscript. CRediT authorship contribution statement Shen Li: Investigation, Writing - review & editing, Supervision, Funding acquisition. Wenjie Sun: Writing - original draft, Visualization. Lijun Wang: Methodology, Data curation. Yuxin Han: Investigation, Data curation. Nannan Liu: Data curation, Supervision. Xinxu Wang: Data curation. Jie Li: Writing- review & editing, Supervision, Conceptualization. Xiang Yang Zhang: Writing- review & editing, Supervision, Funding acquisition, Conceptualization. AI Assistance Statement Artificial intelligence-assisted tools (e.g., ChatGPT) were employed in this study exclusively for language refinement, including grammar correction, style adjustment, and improvement of readability. The tools were not used to generate scientific ideas, analyze data, or create original research content. All outputs from AI assistance were critically reviewed and verified by the authors to ensure accuracy, originality, and compliance with ethical standards of scientific publishing. Declaration of Competing Interest None. Availability of Data and Materials All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Acknowledgment We thank all the participants in the study. References Akaike, H. (1974). 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Tables Table 1 Descriptive Characteristics of Self-Injury in the Past Year Study group, mean (SD), n (%) Variables NSSI (n=1402) Non-NSSI (n=2638) F/Z/χ2 p -value Age 16.06(0.93) 16.08(0.91) -2.819 0.005 Sex Female 730（52.07%） 1329(50.40%) 1.046 0.307 Male 672（47.93%） 1309(49.60%) a Only-child status Yes 79 (5.63%) 159 (6.03%) 0.254 0.614 No 1323 (94.37%) 2479 (93.97%) b Living style Living with parents 670 (47.79%) 1337 (50.68%) 3.066 0.08 Others 732 (52.21%) 1301 (49.32%) Note: NSSI, non-suicidal self-injury; a Only-child status: whether you are an only child. If not, your status includes whether you are the first, second, etc. in the family; b Living style with family members: including long-term cohabitation with parents, one parent away from home for a long time, both parents away for a long time, living with grandparents, single-parent families, etc. Table 2 Comparisons of ISI, MAAS, and DERS scores between the non-NSSI and NSSI groups Study group, mean (SD) Variable NSSI Non-NSSI p-value Cohen’s d (95% CI) ISI-Total 9.31 (5.58) 5.70 (4.60) <0.001 0.73 [0.660, 0.793] MAAS-Total 58.82 (12.74) 68.27 (11.79) <0.001 −0.78 [−0.85, −0.71] Nonacceptance 14.59 (5.17) 11.13 (4.22) <0.001 0.76 [0.69, 0.83] Goals 9.50 (4.29) 6.81 (3.70) <0.001 0.69 [0.62, 0.75] Impulse 9.75 (5.25) 6.07 (4.01) <0.001 0.82 [0.75, 0.89] Awareness -16.57 (4.53) -15.35 (4.61) <0.001 −0.27 [−0.33, −0.20] Strategies 15.83 (6.92) 10.64 (5.36) <0.001 0.87 [0.80, 0.94] Clarity 1.04 (3.03) -0.36 (2.76) <0.001 0.49 [0.42, 0.56] DERS-Total 34.14 (19.56) 18.94 (15.81) <0.001 pFDR < .001 0.88 [0.82, 0.95] Note: NSSI, non-suicidal self-injury, refers to Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire scores; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale; Nonacceptance, nonacceptance of emotional responses; Goals, difficulties engaging in goal-directed behavior; Impulse, impulse control difficulties; Awareness, lack of emotional awareness; Strategies, limited access to emotion regulation strategies; Clarity, lack of emotional clarity. p ( FDR ) values were adjusted for multiple testing using the Benjamini–Hochberg false discovery rate (FDR) procedure across m = 7 comparisons (DERS total scores and six subscales). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 17 Dec, 2025 Reviews received at journal 15 Dec, 2025 Reviews received at journal 12 Dec, 2025 Reviewers agreed at journal 03 Dec, 2025 Reviewers agreed at journal 21 Nov, 2025 Reviewers invited by journal 22 Sep, 2025 Editor assigned by journal 22 Sep, 2025 Submission checks completed at journal 22 Sep, 2025 First submitted to journal 18 Sep, 2025 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. 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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-7650893","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":524639493,"identity":"592d9fec-40ce-4f46-b8c7-e0b51587f89d","order_by":0,"name":"Shen 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09:15:23","extension":"xml","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":92702,"visible":true,"origin":"","legend":"","description":"","filename":"a123e99b383c46b08d09c02a0ab70be51structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/d4854eff893bbcf061013417.xml"},{"id":92844197,"identity":"e428f42e-f030-4e7f-97ce-4b7f261136fb","added_by":"auto","created_at":"2025-10-06 09:23:23","extension":"html","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":104826,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/926a644c50b68d99226b2df6.html"},{"id":92844206,"identity":"3176332f-4e46-4ae9-b837-fe444c7da1a2","added_by":"auto","created_at":"2025-10-06 09:23:23","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":141674,"visible":true,"origin":"","legend":"\u003cp\u003eScatterplot matrix of ISI, DERS, and MAAS showing variable distributions and pairwise associations, stratified by NSSI and Non-NSSI groups.\u003c/p\u003e\n\u003cp\u003eNote: NSSI, non-suicidal self-injury,refers to Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire scores; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale;\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/671e9b38369e0932839b5aa3.jpg"},{"id":92842749,"identity":"bca5600e-1bf9-4b3f-9ff3-b708968ed3a7","added_by":"auto","created_at":"2025-10-06 09:15:23","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":104988,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation scatter plots showing associations of NSSI with ISI, DERS, and MAAS.\u003c/p\u003e\n\u003cp\u003eNote: Correlations between NSSI and each of insomnia severity, difficulties in emotion regulation, and mindfulness among adolescents with past-year NSSI. a Correlation between total scores of NSSI and ISI; b, correlation between total scores of NSSI_behavior and DERS; c, correlation between total scores of NSSI_behavior and MAAS. Abbreviations: NSSI, non-suicidal self-injury, adopts Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire scores; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/c72801bcd1a7a8b6b865dd47.jpg"},{"id":92844194,"identity":"bbc0ae2d-f899-4636-b119-d2aa5ac57936","added_by":"auto","created_at":"2025-10-06 09:23:22","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":63290,"visible":true,"origin":"","legend":"\u003cp\u003eA path diagram illustrating a moderated mediation model among insomnia, emotion dysregulation, mindfulness, and NSSI.\u003c/p\u003e\n\u003cp\u003eNote: NSSI, non-suicidal self-injury; refers to Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale. Moderated mediation model involving the associations between emotion regulation, insomnia, mindfulness, and NSSI. Numbers are standardized regression coefficients. *** = p\u0026lt;0.001\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/b0c2b0a7bcb5abc93d059c76.jpg"},{"id":92842754,"identity":"bee86d8f-eaaf-437a-b1ed-f259d00ac185","added_by":"auto","created_at":"2025-10-06 09:15:23","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":56093,"visible":true,"origin":"","legend":"\u003cp\u003eA simple slopes plot illustrating the moderating effect of mindfulness on the relationship between emotion dysregulation and NSSI.\u003c/p\u003e\n\u003cp\u003eNote: Moderating effect of mindfulness on the relationship between emotion disorder and NSSI. Abbreviations: NSSI, non-suicidal self-injury\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/1dd045ad566829b4ce15134c.jpg"},{"id":92844449,"identity":"8191f81e-ef57-4242-afd7-762ad544fb11","added_by":"auto","created_at":"2025-10-06 09:23:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1223429,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7650893/v1/e90c339c-0cef-4467-8b6c-c9f5c8977380.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Emotion regulation mediates the effect of insomnia on non-suicidal self-injury in adolescents: The moderating role of mindfulness","fulltext":[{"header":"Introduction","content":"\u003cp\u003eNon-suicidal self-injury (NSSI), defined as the intentional, direct harm to one\u0026rsquo;s own body tissue without suicidal intent (Nock \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), includes behaviors such as cutting, burning, hitting, or scratching. Among adolescents, NSSI has become a significant public health challenge. A recent meta-analysis estimated the prevalence of NSSI among Chinese adolescents at 22.4% (McEvoy, Brannigan et al. 2023). This behavior is consistently linked to emotional dysregulation (Hornor \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), underscoring its clinical importance and the urgent need for targeted interventions. Despite growing awareness, prevention and intervention efforts remain limited, particularly within the domestic context. Clarifying the psychological mechanisms underlying NSSI is essential to inform evidence-based strategies and reduce its prevalence (Brown and Plener \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2017\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eOne emerging contributor to NSSI is insomnia, a condition characterized by persistent difficulties in initiating or maintaining sleep, or early morning awakenings (Morin, Drake et al. 2015). A growing body of evidence links insomnia to increased risk of NSSI (Chen, Gong et al. 2025), particularly among adolescents. This relationship is especially pronounced when emotional regulation capacities are compromised (Yang and Zhao \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Insomnia can heighten emotional reactivity and reduce coping capacity, making self-injury a more likely response to negative affect(Hysing, Sivertsen et al. 2015). Conversely, NSSI may further disrupt sleep through physical discomfort and psychological distress, suggesting a bidirectional relationship (Yang and Zhao \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). This association appears strongest among adolescents with poor emotion regulation, pointing to a potentially modifiable mediating mechanism.\u003c/p\u003e\u003cp\u003eEmotion regulation, the ability to monitor, evaluate, and modify emotional responses, has been proposed as a key psychological link between insomnia and behavioral outcomes such as NSSI(Latina, Bauducco et al. 2021). Individuals with insomnia often exhibit diminished emotional awareness, poor cognitive flexibility, and greater reliance on maladaptive regulation strategies (Ballesio, Aquino et al. 2019). NSSI, in turn, is frequently used as a maladaptive but temporarily effective strategy to relieve acute negative emotional states (Zetterqvist, Lundh et al. 2013). These overlapping features suggest that emotion regulation difficulties may represent a central pathway through which insomnia contributes to self-injurious behavior (Bauducco, Tilton-Weaver et al. 2025), offering a potential for clinical intervention.\u003c/p\u003e\u003cp\u003eMindfulness, the practice of nonjudgmental awareness of the present moment (Keng, Smoski et al. 2011), has received increasing attention for its protective role in adolescent mental health (Creswell \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). It has been shown to promote adaptive emotion regulation by enhancing emotional clarity, reducing cognitive reactivity, and curbing maladaptive processes such as rumination and impulsivity (Khoury, Lecomte et al. 2013). These mechanisms may lower the risk of NSSI, particularly among individuals with emotion regulation difficulties (Per, Simundic et al. 2022). Furthermore, mindfulness may buffer the emotional consequences of insomnia, attenuating its impact on stress reactivity and maladaptive coping behaviors (Rusch, Rosario et al. 2019). However, the moderating role of mindfulness in the insomnia\u0026ndash;emotion regulation\u0026ndash;NSSI pathway has yet to be systematically examined in adolescent populations, who are particularly vulnerable to both sleep disturbances and emotional dysregulation.\u003c/p\u003e\u003cp\u003eTo our knowledge, no prior study has simultaneously examined both the mediating role of emotion regulation and the moderating role of mindfulness in the link between insomnia and NSSI among adolescents. The present study investigates the interrelationships among insomnia, emotion regulation, mindfulness, and NSSI in a large adolescent sample. Using structural equation modeling (SEM), we test a moderated mediation model to examine: 1) whether emotion regulation mediates the association between insomnia and NSSI; 2) whether mindfulness moderates this indirect pathway; and 3) whether different components of emotion regulation contribute differentially to this relationship.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Study setting and participants\u003c/h2\u003e\u003cp\u003eThis cross-sectional study was conducted at Huajian Technology Vocational School in Ganzhou City, China. A total of 4,259 students were invited to participate in a school-wide survey assessing sleep behavior, emotion regulation, mindfulness, and self-injurious behaviors. Data were collected through a supervised, self-administered paper-and-pencil questionnaire completed in classroom settings. After rigorous data screening to exclude incomplete or logically inconsistent responses, 4,040 valid cases were retained for analysis, yielding a high response rate. Participants ranged in age from 13 to 21 years (M\u0026thinsp;=\u0026thinsp;16.06, SD\u0026thinsp;=\u0026thinsp;0.92), with 59% identifying as female.\u003c/p\u003e\u003cp\u003e Written informed consent was obtained from all participants, with parental consent additionally secured for minors. Ethical approval was obtained from the Institutional Review Board of Tianjin Anding Hospital.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Measures\u003c/h2\u003e\u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\u003ch2\u003e2.2.1 Insomnia\u003c/h2\u003e\u003cp\u003eInsomnia symptoms were assessed using the Insomnia Severity Index (ISI), a 7-item self-report measure developed to evaluate perceived sleep difficulties over the past two weeks (Rosch \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e1994\u003c/span\u003e). Items cover domains such as sleep onset and maintenance, satisfaction with sleep, interference with daytime functioning, and sleep-related distress. Responses are rated on a 5-point Likert scale (0 = \u0026ldquo;no problem\u0026rdquo; to 4 = \u0026ldquo;very severe problem\u0026rdquo;), yielding a total score ranging from 0 to 28. Standard clinical cutoffs categorize scores into no insomnia (0\u0026ndash;7), subthreshold insomnia (8\u0026ndash;14), moderate insomnia (15\u0026ndash;21), and severe insomnia (22\u0026ndash;28) (Bastien 2001). The ISI has demonstrated strong psychometric properties across diverse populations (Manzar, Jahrami et al. 2021). In this sample, internal consistency was excellent (Cronbach\u0026rsquo;s α\u0026thinsp;=\u0026thinsp;0.94).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003e2.2.2 Emotion regulation\u003c/h2\u003e\u003cp\u003eEmotion regulation difficulties were measured using the Difficulties in Emotion Regulation Scale (DERS), a 36-item self-report instrument assessing problems in six domains: nonacceptance of emotions, difficulty engaging in goal-directed behavior, impulse control difficulties, lack of emotional awareness, limited access to regulation strategies, and lack of emotional clarity (Gratz and Roemer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). Items are rated on a 5-point Likert scale (1 = \u0026ldquo;almost never\u0026rdquo; to 5 = \u0026ldquo;almost always\u0026rdquo;). Eleven items are reverse-scored to maintain consistency in direction. Total scores range from 36 to 180, with higher scores indicating greater emotion dysregulation. Previous studies have shown strong psychometric properties, including internal consistency (α\u0026thinsp;=\u0026thinsp;0.93\u0026ndash;0.96) and test-retest reliability (ICC\u0026thinsp;=\u0026thinsp;0.88). In the current study, internal consistency was excellent for the total score (α\u0026thinsp;=\u0026thinsp;0.94) and ranged from 0.81 to 0.92 across subscales.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\u003ch2\u003e2.2.3 Mindfulness assessment\u003c/h2\u003e\u003cp\u003eTrait mindfulness was assessed using the Chinese version of the Mindful Attention Awareness Scale (MAAS) (Brown and Ryan \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2003\u003c/span\u003e, Deng, Li et al. 2012). The MAAS consists of 15 items measuring attention to and awareness of present-moment experiences. Items are rated on a 6-point Likert scale ranging from 1 (\u0026ldquo;almost always\u0026rdquo;) to 6 (\u0026ldquo;almost never\u0026rdquo;), with higher mean scores reflecting greater mindfulness. The MAAS has shown high internal consistency in Chinese adolescent samples (α\u0026thinsp;=\u0026thinsp;0.89\u0026ndash;0.93) (Black, Sussman et al. 2012). In this study, internal consistency was strong (Cronbach\u0026rsquo;s α\u0026thinsp;=\u0026thinsp;0.89).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\u003ch2\u003e2.2.4 NSSI\u003c/h2\u003e\u003cp\u003eNSSI was measured using the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire (ANSAQ), a validated self-report tool developed to assess both behavioral frequency and functional motivations for NSSI in adolescents (Whitlock, Exner-Cortens et al. 2014). The behavioral section consists of 12 items assessing NSSI behaviors over the past 12 months, categorized into behaviors without significant tissue damage (7 items, e.g., scratching, hair pulling) and those with evident tissue damage (5 items, e.g., cutting, burning). A total behavioral frequency score is computed by summing item responses. The functional section includes subscales assessing intrapersonal and interpersonal functions of NSSI.\u003c/p\u003e\u003cp\u003eThe ANSAQ has demonstrated robust psychometric properties: behavioral subscale internal consistency (α\u0026thinsp;=\u0026thinsp;0.921), split-half reliability (r\u0026thinsp;=\u0026thinsp;0.851), and test\u0026ndash;retest reliability (r\u0026thinsp;=\u0026thinsp;0.843). The functional component also showed satisfactory internal consistency (α\u0026thinsp;=\u0026thinsp;0.813). In this study, internal consistency was comparable, supporting its use in this population.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Statistical analysis\u003c/h2\u003e\u003cp\u003eAll statistical analyses were conducted using SPSS version 27 (IBM Corp., Armonk, NY) and Mplus version 8.3 (Muth\u0026eacute;n \u0026amp; Muth\u0026eacute;n, Los Angeles, CA). The analysis followed a multi-step approach to examine the associations among insomnia, emotion regulation, mindfulness, and NSSI.\u003c/p\u003e\u003cp\u003eDescriptive statistics and bivariate correlations were computed for all study variables. The Kolmogorov\u0026ndash;Smirnov test was used to assess the normality of continuous variable distributions. For variables that did not meet normality assumptions, non-parametric tests were employed: Mann\u0026ndash;Whitney U tests for two-group comparisons and Kruskal\u0026ndash;Wallis H tests for comparisons involving more than two groups. Categorical variables were analyzed using Pearson\u0026rsquo;s chi-square test. Continuous variables are reported as mean (standard deviation, SD) or median (interquartile range, IQR), depending on distributional characteristics. Statistical significance was set at two-tailed p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003cp\u003eGroup differences in emotion regulation between adolescents with and without NSSI were tested using independent-samples t-tests. Welch\u0026rsquo;s correction was applied when homogeneity of variance was violated. To control for Type I error across the DERS total score and its six subscales, p-values were adjusted using the Benjamini\u0026ndash;Hochberg false discovery rate (FDR), targeting a 5% false discovery rate. Effect sizes were calculated using Hedges\u0026rsquo; g, with 95% confidence intervals (CIs) reported to aid interpretation.\u003c/p\u003e\u003cp\u003eTo test our core hypotheses, we estimated an observed-variable moderated mediation model in Mplus (Muller, Judd et al. 2005). Insomnia was specified as the predictor, emotion regulation as the mediator, mindfulness as the moderator, and NSSI as the outcome. An interaction term (emotion regulation \u0026times; mindfulness) was computed using mean-centered variables and included in the model to test for conditional effects. This model included two regression paths: (1) the mediator (emotion regulation) was regressed on the predictor (insomnia) and moderator (mindfulness); (2) the outcome (NSSI) was regressed on the predictor, mediator, and the mediator\u0026times;moderator interaction.\u003c/p\u003e\u003cp\u003eParameter estimation used full information maximum likelihood (FIML), which allows for robust handling of missing data under the assumption of missing at random (MAR). Indirect effects were tested using 5,000 bias-corrected bootstrap resamples. Statistical significance was determined by whether the 95% bootstrap confidence interval excluded zero\u003c/p\u003e\u003cp\u003eTo interpret the interaction between emotion regulation and mindfulness, simple slope analyses were conducted (Montoya \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Conditional effects of emotion dysregulation on NSSI were estimated at three levels of mindfulness: one standard deviation below the mean (low), at the mean (moderate), and one standard deviation above the mean (high). This approach enabled a nuanced interpretation of how trait mindfulness moderates the impact of emotional dysregulation on NSSI.\u003c/p\u003e\u003cp\u003eGiven that we specified an observed-variable model including a product interaction term, conventional structural equation modeling fit indices (e.g., CFI, TLI, RMSEA) were not reported. Instead, model adequacy was evaluated using information-theoretic indices: the Akaike Information Criterion (AIC) (Akaike \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1974\u003c/span\u003e) and Bayesian Information Criterion (BIC) (Schwarz \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e1978\u003c/span\u003e). These criteria are well-suited for model selection in complex behavioral datasets, balancing model fit against parsimony; lower values indicate a better trade-off. Model convergence and numerical integration diagnostics were inspected to ensure stability and computational validity (Heinze, Wallisch et al. 2018, Dziak, Coffman et al. 2020).\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Baseline characteristics of adolescents and correlations between variables\u003c/h2\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e presents the distribution of and bivariate correlations among key study variables. The kernel density plots revealed that, compared to the Non-NSSI group, the NSSI group demonstrated a shift towards higher scores on the ISI and DERS, and lower scores on the MAAS. The correlation patterns were consistent across groups but stronger in the NSSI group. Insomnia severity was negatively correlated with mindfulness (Non-NSSI: r = -0.49; NSSI: r = -0.55) and positively correlated with emotion dysregulation (Non-NSSI: r\u0026thinsp;=\u0026thinsp;0.40; NSSI: r\u0026thinsp;=\u0026thinsp;0.47). Mindfulness was negatively correlated with emotion dysregulation in both groups (Non-NSSI: r = -0.54; NSSI: r = -0.58). Furthermore, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows that in the NSSI group, the total NSSI-behavior score was positively correlated with insomnia severity (r\u0026thinsp;=\u0026thinsp;0.28) and emotion dysregulation (r\u0026thinsp;=\u0026thinsp;0.31), and negatively correlated with mindfulness (r = -0.33).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e\u003cem\u003e3.2\u003c/em\u003e Psychological Profiles Differentiate NSSI and Non-NSSI Groups\u003c/h2\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e presents significant differences emerged across all psychological measures between the NSSI and Non-NSSI groups. Participants with NSSI reported substantially higher insomnia severity compared to non-self-injuring individuals (Cohen\u0026rsquo;s d\u0026thinsp;=\u0026thinsp;0.71, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Similarly, the NSSI group demonstrated markedly lower mindfulness (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). For DERS, the NSSI cohort scored significantly higher on all subscales and the total score (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 for all comparisons). Largest effects were observed for impulse control difficulties (d\u0026thinsp;=\u0026thinsp;0.81; NSSI M\u0026thinsp;=\u0026thinsp;9.75, SD\u0026thinsp;=\u0026thinsp;5.25 ; non-NSSI M\u0026thinsp;=\u0026thinsp;6.07, SD\u0026thinsp;=\u0026thinsp;4.01) and limited emotion regulation strategies (d\u0026thinsp;=\u0026thinsp;0.84; NSSI M\u0026thinsp;=\u0026thinsp;15.83, SD\u0026thinsp;=\u0026thinsp;6.92 ; non-NSSI M\u0026thinsp;=\u0026thinsp;10.64, SD\u0026thinsp;=\u0026thinsp;5.36). Notably, lack of emotional awareness showed a reversed scoring pattern yet remained significantly elevated in the NSSI group (d\u0026thinsp;=\u0026thinsp;0.27, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). All DERS findings retained significance after false discovery rate correction (p-FDR\u0026thinsp;\u0026lt;\u0026thinsp;.001 across 7 comparisons).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003epresents the demographic characteristics of the study participants. Among 4,040 adolescents, 1,402 (34.70%) reported NSSI and 2,638 did not. Age differed slightly between groups (p\u0026thinsp;=\u0026thinsp;0.005), a statistically significant but trivial difference (SMD\u0026thinsp;=\u0026thinsp;0.02). Sex distribution was comparable (p\u0026thinsp;=\u0026thinsp;0.307). Only-child status was similar (p\u0026thinsp;=\u0026thinsp;0.614). Numerically fewer adolescents with NSSI lived with parents, but the difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.080).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eStudy group, mean (SD), n (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNSSI\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;1402)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNon-NSSI\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;2638)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eF/Z/χ2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e16.06(0.93)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16.08(0.91)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-2.819\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e730(52.07%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1329(50.40%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.046\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.307\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e672(47.93%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1309(49.60%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003csup\u003ea\u003c/sup\u003eOnly-child status\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e79 (5.63%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e159 (6.03%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.254\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.614\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1323 (94.37%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2479 (93.97%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003csup\u003eb\u003c/sup\u003eLiving style\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLiving with parents\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e670 (47.79%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1337 (50.68%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.066\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOthers\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e732 (52.21%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1301 (49.32%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eDescriptive Characteristics of Self-Injury in the Past Year\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\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\u003eComparisons of ISI, MAAS, and DERS scores between the non-NSSI and NSSI groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eStudy group, mean (SD)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNSSI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNon-NSSI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003ep-value\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eCohen\u0026rsquo;s d (95% CI)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eISI-Total\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.31 (5.58)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.70 (4.60)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.73 [0.660, 0.793]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMAAS-Total\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e58.82 (12.74)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e68.27 (11.79)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026minus;0.78 [\u0026minus;\u0026thinsp;0.85, \u0026minus;\u0026thinsp;0.71]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNonacceptance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14.59 (5.17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11.13 (4.22)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.76 [0.69, 0.83]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGoals\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.50 (4.29)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.81 (3.70)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.69 [0.62, 0.75]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eImpulse\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.75 (5.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.07 (4.01)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.82 [0.75, 0.89]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAwareness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-16.57 (4.53)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-15.35 (4.61)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026minus;0.27 [\u0026minus;\u0026thinsp;0.33, \u0026minus;\u0026thinsp;0.20]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStrategies\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15.83 (6.92)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.64 (5.36)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.87 [0.80, 0.94]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eClarity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.04 (3.03)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.36 (2.76)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.49 [0.42, 0.56]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDERS-Total\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.14 (19.56)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18.94 (15.81)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003csub\u003epFDR\u0026thinsp;\u0026lt;\u0026thinsp;.001\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.88 [0.82, 0.95]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eNote: NSSI, non-suicidal self-injury, refers to Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire scores; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale; Nonacceptance, nonacceptance of emotional responses; Goals, difficulties engaging in goal-directed behavior; Impulse, impulse control difficulties; Awareness, lack of emotional awareness; Strategies, limited access to emotion regulation strategies; Clarity, lack of emotional clarity. p(FDR) values were adjusted for multiple testing using the Benjamini\u0026ndash;Hochberg false discovery rate (FDR) procedure across m\u0026thinsp;=\u0026thinsp;7 comparisons (DERS total scores and six subscales).\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.3 The moderated mediating model\u003c/h2\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e presents a moderated mediation model tested with 5,000 bootstrap samples on NSSI groups using maximum likelihood estimation. We compared an interaction model with a reduced model omitting the interaction. Likelihood-based information criteria favored the interaction specification (AIC\u0026thinsp;=\u0026thinsp;20,637.99; BIC\u0026thinsp;=\u0026thinsp;20,685.19; sample-size adjusted BIC\u0026thinsp;=\u0026thinsp;20,656.60) over the reduced model (AIC\u0026thinsp;=\u0026thinsp;20,672.15; BIC\u0026thinsp;=\u0026thinsp;20,714.11; adjusted BIC\u0026thinsp;=\u0026thinsp;20,688.70); ΔBIC\u0026thinsp;=\u0026thinsp;29.00 indicates very strong evidence for the interaction model. A likelihood-ratio test corroborated this improvement (p\u0026thinsp;\u0026lt;\u0026thinsp;.001). The model showed acceptable fit. The independent variable insomnia significantly predicted the mediator (difficulties in emotion regulation; β\u0026thinsp;=\u0026thinsp;0.220, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), while the moderator mindfulness negatively predicted mediator (β = -0.456, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In the outcome model, insomnia (β\u0026thinsp;=\u0026thinsp;0.117, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), difficulties in emotion regulation (β\u0026thinsp;=\u0026thinsp;0.228, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and the interaction term (β = -0.269, p\u0026thinsp;=\u0026thinsp;0.001) were all significant predictors of NSSI, indicating both mediation and moderation effects. The average indirect effect was significant (Indirect effect\u0026thinsp;=\u0026thinsp;0.176, 95% bootstrap CI [0.115, 0.248]), supporting a mediation mechanism.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows the strength of the mediation effect at different levels of mindfulness as the moderator. In the NSSI group, the indirect effects were significant at the mean and \u0026plusmn;\u0026thinsp;1 SD of MAAS scores in the NSSI group, with a smaller effect at high mindfulness (Indirect\u0026thinsp;=\u0026thinsp;0.155, 95% CI [0.105, 0.213]) and a larger effect at low mindfulness (Indirect\u0026thinsp;=\u0026thinsp;0.198, 95% CI [0.125, 0.284]), suggesting that mindfulness moderated the strength of the mediation effect.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eTo our knowledge, this is the first study to simultaneously examine the mediating role of emotion regulation and the moderating role of mindfulness in the relationship between insomnia and NSSI among adolescents. The findings provide novel insight into how psychological vulnerabilities and protective factors interact to influence self-injurious behavior in this population. First, adolescents who engaged in NSSI reported significantly greater insomnia severity, more pronounced emotion regulation difficulties, and lower levels of mindfulness compared to their peers without NSSI. Second, insomnia was indirectly associated with increased risk of NSSI through its impact on emotion regulation, supporting the hypothesis that sleep disturbances may heighten emotional dysregulation, thereby increasing vulnerability to self-injury. Third, mindfulness significantly attenuated this indirect effect: adolescents with higher levels of mindfulness showed a weaker link between insomnia and emotion dysregulation, which in turn reduced the likelihood of NSSI. These findings highlight the dual role of emotion regulation as a risk mechanism and mindfulness as a resilience factor, underscoring their relevance as potential targets for prevention and early intervention efforts.\u003c/p\u003e\u003cp\u003eWe observed a 12-month NSSI prevalence of 34.7% among Chinese vocational high school students, substantially higher than previously reported estimates (McEvoy, Brannigan et al. 2023). Several factors may account for this elevated rate. First, NSSI tends to peak during mid-adolescence, when emotional regulation systems are still maturing and individuals face increasing academic and interpersonal stressors. Prior research has shown that adolescents in East Asian contexts may report particularly high NSSI prevalence due to the unique sociocultural pressures associated with education and family expectations (Farkas, Takacs et al. 2024) (Plener, Allroggen et al. 2016). Second, our sample, drawn from a vocational school, may reflect a subgroup with distinct academic and psychosocial vulnerabilities that heighten NSSI risk.\u003c/p\u003e\u003cp\u003eInterestingly, living arrangements (i.e., whether adolescents lived with their family members) were not significantly associated with NSSI risk. This may be due to the operationalization of \u0026ldquo;lifestyle\u0026rdquo; as a structural variable (e.g., co-residence with parents), rather than capturing the quality of family functioning. Previous research has demonstrated that emotional family climate, characterized by support, warmth, or conflict, is a more robust predictor of adolescent psychological outcomes than structural family variables alone (Gratz and Roemer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). Within collectivistic cultures such as China\u0026rsquo;s, adolescents may be particularly influenced by the emotional dynamics of their family system (Zhou, Kyeong et al. 2022), which should be better captured in future research.\u003c/p\u003e\u003cp\u003eConsistent with prior work, we found that adolescents who engaged in NSSI reported significantly higher difficulties across all six subdomains of emotion regulation. This aligns with neurobiological models suggesting impaired top-down regulatory control, including amygdala hyper-reactivity and weakened prefrontal cortical modulation of negative affect (Westlund Schreiner, Klimes-Dougan et al. 2017). Emotionally dysregulated youth may be more likely to rely on maladaptive coping strategies, such as suppression or rumination, which further reinforce emotional distress and increase vulnerability to self-injury (Gratz and Roemer \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). These findings reinforce emotion regulation as a central transdiagnostic mechanism and a potential therapeutic target.\u003c/p\u003e\u003cp\u003eAdolescents with a recent history of NSSI also exhibited significantly lower levels of trait mindfulness compared to their non-NSSI peers. This is in line with studies showing that mindfulness enhances attentional control, reduces automatic reactivity to distressing stimuli, and fosters decentering from negative thoughts (Marchand \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2014\u003c/span\u003e, Guendelman, Medeiros et al. 2017). More importantly, our moderated mediation model demonstrated that mindfulness significantly buffered the indirect effect of insomnia on NSSI via emotion regulation. That is, adolescents with higher levels of mindfulness showed less emotion dysregulation in response to insomnia symptoms, which in turn reduced their likelihood of engaging in NSSI. This finding is consistent with meta-analytic evidence supporting the efficacy of mindfulness-based interventions in enhancing emotional resilience(Khoury et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) (Guendelman, Medeiros et al. 2017), which may indirectly reduce vulnerability to maladaptive behaviors such as NSSI. Randomized trials have further shown that even brief mindfulness-based interventions can improve regulatory capacity and reduce NSSI risk (Zheng, Chen et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2025\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eOur findings also confirmed that adolescents with NSSI reported significantly greater insomnia symptoms. This is consistent with evidence suggesting that insomnia contributes to persistent hyperarousal, potentially driven by dysregulation of the hypothalamic\u0026ndash;pituitary\u0026ndash;adrenal (HPA) axis, which impairs both sleep onset and continuity (Reichl, Heyer et al. 2016). Experimental studies show that sleep deprivation impairs prefrontal inhibitory control and increases impulsivity and risk-taking, particularly during nocturnal or fatigue states\u0026mdash;factors that may facilitate self-injurious behaviors (Leone, Kuja-Halkola et al. 2023). Our data also support the proposed mechanistic link between sleep disturbance and emotion regulation: insomnia predicted increased emotion dysregulation, which in turn elevated NSSI risk. This may reflect sleep-related disruption of prefrontal\u0026ndash;amygdala connectivity, which diminishes top-down modulation of negative affect and heightens emotional intensity (Yoo, Gujar et al. 2007)(Yoo, Gujar et al. 2007).\u003c/p\u003e\u003cp\u003eMoreover, the results indicated that mindfulness capacity could play a moderating role within this pathway. Consistent with previous accounts, meta-analytic evidence shows that mindfulness-based interventions improve regulatory capacities and psychiatric outcomes, suggesting modifiability of the pathway\u0026rsquo;s strength (Khoury, Lecomte et al. 2013). Neurocognitive models highlight that mindfulness strengthens top-down attentional regulation, promotes decentering from distressing thoughts, and facilitates flexible emotional responding, thereby reducing reliance on maladaptive strategies (Guendelman, Medeiros et al. 2017). Mindfulness-based interventions could be effective in reducing NSSI behaviors, offering a practical avenue for supporting adolescents experiencing insomnia-related emotional challenges.\u003c/p\u003e\u003cp\u003eSeveral limitations should be acknowledged. First, the cross-sectional design precludes causal inference; longitudinal and experimental designs are needed to clarify the temporal directionality among insomnia, emotion regulation, and NSSI. Second, the sample was drawn from a single vocational school in China, which may limit the generalizability of findings to other adolescent populations. Third, all variables were assessed via self-report, which may be subject to recall bias or social desirability effects. Finally, while we included several key psychological constructs, we did not assess potential confounders such as trauma history, peer victimization, or detailed family functioning, all of which may influence both sleep and self-injurious behaviors.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThis study reveals that insomnia contributes to adolescent NSSI through emotion regulation difficulties, with mindfulness acting as a protective moderator. These findings highlight the importance of addressing sleep problems and emotional vulnerability in youth, while also supporting the use of mindfulness-based strategies in prevention efforts. Targeting these modifiable factors may offer effective pathways for reducing self-injurious behaviors among at-risk adolescents.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Ministry of Education, Humanities and Social Sciences Youth Fund (23YJCZH106). All funding had no role in study design, data analysis, article submission and publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors have contributed to and have approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCRediT authorship contribution statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eShen Li: Investigation, Writing - review \u0026amp; editing, Supervision, Funding acquisition. Wenjie Sun: Writing - original draft, Visualization. Lijun Wang: Methodology, Data curation. Yuxin Han: Investigation, Data curation. Nannan Liu: Data curation, Supervision. Xinxu Wang: Data curation. Jie Li: Writing- review \u0026amp; editing, Supervision, Conceptualization. Xiang Yang Zhang: Writing- review \u0026amp; editing, Supervision, Funding acquisition, Conceptualization.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAI Assistance Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eArtificial intelligence-assisted tools (e.g., ChatGPT) were employed in this study exclusively for language refinement, including grammar correction, style adjustment, and improvement of readability. The tools were not used to generate scientific ideas, analyze data, or create original research content. All outputs from AI assistance were critically reviewed and verified by the authors to ensure accuracy, originality, and compliance with ethical standards of scientific publishing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of Competing Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data and Materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank all the participants in the study.\u003c/p\u003e"},{"header":"References","content":"\u003cp\u003eAkaike, H. 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Roemer (2004). \"Multidimensional Assessment of Emotion Regulation and Dysregulation: Development, Factor Structure, and Initial Validation of the Difficulties in Emotion Regulation Scale.\" \u003cu\u003eJournal of Psychopathology and Behavioral Assessment\u003c/u\u003e \u003cstrong\u003e26\u003c/strong\u003e(1): 41-54.\u003c/p\u003e\n\u003cp\u003eGuendelman, S., et al. (2017). \"Mindfulness and Emotion Regulation: Insights from Neurobiological, Psychological, and Clinical Studies.\" \u003cu\u003eFrontiers in Psychology\u003c/u\u003e \u003cstrong\u003e8\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eHeinze, G., et al. (2018). \"Variable selection – A review and recommendations for the practicing statistician.\" \u003cu\u003eBiometrical Journal\u003c/u\u003e \u003cstrong\u003e60\u003c/strong\u003e(3): 431-449.\u003c/p\u003e\n\u003cp\u003eHornor, G. 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(2021). \"Insomnia symptoms and non‐suicidal self‐injury in adolescence: understanding temporal relations and mechanisms.\" \u003cu\u003eJournal of Sleep Research\u003c/u\u003e \u003cstrong\u003e30\u003c/strong\u003e(1): e13190.\u003c/p\u003e\n\u003cp\u003eLeone, M., et al. (2023). \"Melatonin use and the risk of self‐harm and unintentional injuries in youths with and without psychiatric disorders.\" \u003cu\u003eJournal of Child Psychology and Psychiatry\u003c/u\u003e \u003cstrong\u003e64\u003c/strong\u003e(7): 1027-1036.\u003c/p\u003e\n\u003cp\u003eMarchand, W. R. (2014). \"Neural mechanisms of mindfulness and meditation: Evidence from neuroimaging studies.\" \u003cu\u003eWorld Journal of Radiology\u003c/u\u003e \u003cstrong\u003e6\u003c/strong\u003e(7): 471.\u003c/p\u003e\n\u003cp\u003eMcEvoy, D., et al. (2023). \"Risk and protective factors for self-harm in adolescents and young adults: An umbrella review of systematic reviews.\" \u003cu\u003eJ Psychiatr Res\u003c/u\u003e \u003cstrong\u003e168\u003c/strong\u003e: 353-380.\u003c/p\u003e\n\u003cp\u003eMontoya, A. K. (2019). \"Moderation analysis in two-instance repeated measures designs: Probing methods and multiple moderator models.\" \u003cu\u003eBehavior Research Methods\u003c/u\u003e \u003cstrong\u003e51\u003c/strong\u003e(1): 61-82.\u003c/p\u003e\n\u003cp\u003eMorin, C. M., et al. (2015). \"Insomnia disorder.\" \u003cu\u003eNature Reviews Disease Primers\u003c/u\u003e \u003cstrong\u003e1\u003c/strong\u003e(1): 15026.\u003c/p\u003e\n\u003cp\u003eMuller, D., et al. (2005). \"When moderation is mediated and mediation is moderated.\" \u003cu\u003eJournal of Personality and Social Psychology\u003c/u\u003e \u003cstrong\u003e89\u003c/strong\u003e(6): 852-863.\u003c/p\u003e\n\u003cp\u003eNock, M. K. (2010). \"Self-Injury.\" \u003cu\u003eAnnual Review of Clinical Psychology\u003c/u\u003e \u003cstrong\u003e6\u003c/strong\u003e(1): 339-363.\u003c/p\u003e\n\u003cp\u003ePer, M., et al. (2022). \"Examining the Relationship Between Mindfulness, Self-Compassion, and Emotion Regulation in Self-Injury.\" \u003cu\u003eArchives of Suicide Research\u003c/u\u003e \u003cstrong\u003e26\u003c/strong\u003e(3): 1286-1301.\u003c/p\u003e\n\u003cp\u003ePlener, P. L., et al. (2016). \"The prevalence of Nonsuicidal Self-Injury (NSSI) in a representative sample of the German population.\" \u003cu\u003eBMC Psychiatry\u003c/u\u003e \u003cstrong\u003e16\u003c/strong\u003e(1).\u003c/p\u003e\n\u003cp\u003eReichl, C., et al. (2016). \"Hypothalamic-pituitary-adrenal axis, childhood adversity and adolescent nonsuicidal self-injury.\" \u003cu\u003ePsychoneuroendocrinology\u003c/u\u003e \u003cstrong\u003e74\u003c/strong\u003e: 203-211.\u003c/p\u003e\n\u003cp\u003eRosch, P. J. (1994). \"Insomnia, psychological assessment and management, Charles M. Morin, Guilford Press, New York, 1993. No. of pages: 238. Price: $26.95.\" \u003cu\u003eStress Medicine\u003c/u\u003e \u003cstrong\u003e10\u003c/strong\u003e(1): 69-70.\u003c/p\u003e\n\u003cp\u003eRusch, H. L., et al. (2019). \"The effect of mindfulness meditation on sleep quality: a systematic review and meta‐analysis of randomized controlled trials.\" \u003cu\u003eAnnals of the New York Academy of Sciences\u003c/u\u003e \u003cstrong\u003e1445\u003c/strong\u003e(1): 5-16.\u003c/p\u003e\n\u003cp\u003eSchwarz, G. (1978). \"Estimating the Dimension of a Model.\" \u003cu\u003eThe Annals of Statistics\u003c/u\u003e \u003cstrong\u003e6\u003c/strong\u003e(2): 461-464.\u003c/p\u003e\n\u003cp\u003eWestlund Schreiner, M., et al. (2017). \"Multi-modal neuroimaging of adolescents with non-suicidal self-injury: Amygdala functional connectivity.\" \u003cu\u003eJournal of Affective Disorders\u003c/u\u003e \u003cstrong\u003e221\u003c/strong\u003e: 47-55.\u003c/p\u003e\n\u003cp\u003eYang, J. and Y. Zhao (2024). \"Examining bidirectional relations between sleep problems and non-suicidal self-injury/suicidal behavior in adolescents: emotion regulation difficulties and externalizing problems as mediators.\" \u003cu\u003eEuropean Child \u0026amp;amp; Adolescent Psychiatry\u003c/u\u003e \u003cstrong\u003e33\u003c/strong\u003e(7): 2397-2411.\u003c/p\u003e\n\u003cp\u003eYoo, S.-S., et al. (2007). \"The human emotional brain without sleep — a prefrontal amygdala disconnect.\" \u003cu\u003eCurrent Biology\u003c/u\u003e \u003cstrong\u003e17\u003c/strong\u003e(20): R877-R878.\u003c/p\u003e\n\u003cp\u003eZetterqvist, M., et al. (2013). \"Prevalence and Function of Non-Suicidal Self-Injury (NSSI) in a Community Sample of Adolescents, Using Suggested DSM-5 Criteria for a Potential NSSI Disorder.\" \u003cu\u003eJournal of Abnormal Child Psychology\u003c/u\u003e \u003cstrong\u003e41\u003c/strong\u003e(5): 759-773.\u003c/p\u003e\n\u003cp\u003eZheng, Q., et al. (2025). \"Non-suicidal self-injury risk among left-behind children and adolescents in China: A systematic review and meta-analysis.\" \u003cu\u003eWorld Journal of Psychiatry\u003c/u\u003e \u003cstrong\u003e15\u003c/strong\u003e(2).\u003c/p\u003e\n\u003cp\u003eZhou, E., et al. (2022). \"Shared Cultural Values Influence Mental Health Help-Seeking Behaviors in Asian and Latinx College Students.\" \u003cu\u003eJournal of Racial and Ethnic Health Disparities\u003c/u\u003e \u003cstrong\u003e9\u003c/strong\u003e(4): 1325-1334.\u003c/p\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 Descriptive Characteristics of Self-Injury in the Past Year\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"567\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 254px;\"\u003e\n \u003cp\u003eStudy group, mean (SD), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003eNSSI\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(n=1402)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003eNon-NSSI\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(n=2638)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003eF/Z/\u0026chi;2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e16.06(0.93)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e16.08(0.91)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e-2.819\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e730（52.07%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e1329(50.40%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e1.046\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.307\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e672（47.93%）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e1309(49.60%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003csup\u003ea\u003c/sup\u003eOnly-child status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e79 (5.63%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e159 (6.03%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e0.254\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.614\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e1323 (94.37%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e2479 (93.97%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003csup\u003eb\u003c/sup\u003eLiving style\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eLiving with parents\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e670 (47.79%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e1337 (50.68%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e3.066\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e0.08\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 132px;\"\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 115px;\"\u003e\n \u003cp\u003e732 (52.21%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 139px;\"\u003e\n \u003cp\u003e1301 (49.32%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 92px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: NSSI, non-suicidal self-injury; \u003csup\u003ea\u003c/sup\u003eOnly-child status: whether you are an only child. If not, your status includes whether you are the first, second, etc. in the family; \u003csup\u003eb\u003c/sup\u003eLiving style with family members: including long-term cohabitation with parents, one parent away from home for a long time, both parents away for a long time, living with grandparents, single-parent families, etc.\u003c/p\u003e\n\u003cp\u003eTable 2 Comparisons of ISI, MAAS, and DERS scores between the non-NSSI and NSSI groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"572\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 205px;\"\u003e\n \u003cp\u003eStudy group, mean (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003eNSSI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eNon-NSSI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cem\u003ep-value\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003eCohen\u0026rsquo;s d (95% CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eISI-Total\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e9.31 (5.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e5.70 (4.60)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.73 [0.660, 0.793]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eMAAS-Total\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e58.82 (12.74)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e68.27 (11.79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e\u0026minus;0.78 [\u0026minus;0.85, \u0026minus;0.71]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eNonacceptance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e14.59 (5.17)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e11.13 (4.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.76 [0.69, 0.83]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eGoals\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e9.50 (4.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e6.81 (3.70)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.69 [0.62, 0.75]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eImpulse\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e9.75 (5.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e6.07 (4.01)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.82 [0.75, 0.89]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eAwareness\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e-16.57 (4.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e-15.35 (4.61)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e\u0026minus;0.27 [\u0026minus;0.33, \u0026minus;0.20]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eStrategies\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e15.83 (6.92)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e10.64 (5.36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.87 [0.80, 0.94]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eClarity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e1.04 (3.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e-0.36 (2.76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.49 [0.42, 0.56]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003eDERS-Total\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e34.14 (19.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 106px;\"\u003e\n \u003cp\u003e18.94 (15.81)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003csub\u003epFDR \u0026lt; .001\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 146px;\"\u003e\n \u003cp\u003e0.88 [0.82, 0.95]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: NSSI, non-suicidal self-injury, refers to Behavioral Questionnaire of the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire scores; ISI, Insomnia Severity Index; DERS, Difficulties in Emotion Regulation Scale; MAAS, Mindful Attention Awareness Scale; Nonacceptance, nonacceptance of emotional responses; Goals, difficulties engaging in goal-directed behavior; Impulse, impulse control difficulties; Awareness, lack of emotional awareness; Strategies, limited access to emotion regulation strategies; Clarity, lack of emotional clarity. p\u003csub\u003e(\u003c/sub\u003eFDR\u003csub\u003e)\u003c/sub\u003e values were adjusted for multiple testing using the Benjamini\u0026ndash;Hochberg false discovery rate (FDR) procedure across m = 7 comparisons (DERS total scores and six subscales).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":false,"email":"","identity":"journal-of-neural-transmission","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Journal of Neural Transmission","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"VoR Journals","inReviewEnabled":false,"inReviewRevisionsEnabled":false},"keywords":"non-suicidal self-injury, mindfulness, insomnia, emotion regulation, structural equation model","lastPublishedDoi":"10.21203/rs.3.rs-7650893/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7650893/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eNon-suicidal self-injury (NSSI) is common among adolescents, yet the role of insomnia in its development remains understudied. This study aims to investigate the association between insomnia and NSSI, focusing on the mediating role of emotion regulation and the moderating effect of mindfulness.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eA cross-sectional survey was conducted among 4,259 students at a vocational and technical school in China. Participants were stratified into two groups based on the presence or absence of NSSI behaviors within the past year. Demographic data and standardized assessments were collected, including the Insomnia Severity Index (ISI), Difficulties in Emotion Regulation Scale (DERS), Mindful Attention Awareness Scale (MAAS), and the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire (ANSAQ). Structural equation modeling (SEM) was used to test hypothesized relationships.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAmong the participants, 34.7% (n\u0026thinsp;=\u0026thinsp;1,402) reported NSSI in the past year. Those with NSSI showed significantly higher insomnia severity, greater emotion dysregulation, and lower mindfulness (all \u003cem\u003ep\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e \u0026lt; 0.01). Insomnia was indirectly associated with NSSI through increased emotion regulation difficulties (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01). Mindfulness moderated this pathway, attenuating the impact of insomnia on both emotion dysregulation and subsequent NSSI (both \u003cem\u003ep\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e \u0026lt; 0.01).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eInsomnia increases NSSI risk by impairing emotion regulation, while mindfulness mitigates this effect. These findings highlight key psychological mechanisms and support mindfulness-based approaches in NSSI prevention, particularly for adolescents with low trait mindfulness.\u003c/p\u003e","manuscriptTitle":"Emotion regulation mediates the effect of insomnia on non-suicidal self-injury in adolescents: The moderating role of mindfulness","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-06 09:15:17","doi":"10.21203/rs.3.rs-7650893/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-17T13:40:10+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-15T19:29:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-12T19:51:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"68901419125397232983116254004332533487","date":"2025-12-03T14:44:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"14365208596899292452276441463721273590","date":"2025-11-21T16:27:22+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-22T16:46:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-22T16:11:20+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-22T15:23:42+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Neural Transmission","date":"2025-09-18T14:48:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":false,"email":"","identity":"journal-of-neural-transmission","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Journal of Neural Transmission","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"VoR Journals","inReviewEnabled":false,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"fb14d3c0-580c-46a5-b095-38033e169de5","owner":[],"postedDate":"October 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-01-19T14:58:29+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-06 09:15:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7650893","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7650893","identity":"rs-7650893","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}