Insomnia Severity Predicts Suicide Attempts in Youth with depression: A 6-Month Prospective Cohort Study

Insomnia Severity Predicts Suicide Attempts in Youth with depression: A 6-Month Prospective Cohort Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Insomnia Severity Predicts Suicide Attempts in Youth with depression: A 6-Month Prospective Cohort Study Xuefei Fan, Kunrong Lin, Ziyan Zhou, Xiaoming Lin, Yarong Ma, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9144236/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Background Evidence linking insomnia to suicidal risk in depressed youth is largely cross-sectional, limiting inference about temporal direction. We examined whether baseline insomnia severity predicts subsequent suicide attempts in this population. Methods We conducted a 6-month prospective cohort study of depressed youth recruited from a psychiatric hospital from January to June 2022. We examined the association between baseline insomnia severity and time to first suicide attempt using Kaplan–Meier curves and multivariable Cox proportional hazards models. Results A total of 561 participants were included in the final analysis (428 female participants [76.3%]). At baseline, 458 participants met the criteria for insomnia (Athens Insomnia Scale [AIS] ³6; 81.6%). In multivariable Cox models, insomnia severity was independently associated with a higher hazard of suicide attempts (HR = 1.07, 95% CI = 1.01–1.13, p = 0.038). Kaplan–Meier curves also showed a significant difference in time to first suicide attempt between the insomnia and non-insomnia groups ( p < 0.001). In addition, greater depressive severity (HR = 1.11, 95% CI = 1.04–1.18, p = 0.002), and a lifetime history of suicidality (HR = 2.14, 95%CI = 1.31–3.48, p = 0.004) predicted follow-up attempts, whereas a longer illness duration (>24 months) was associated with a lower hazard (HR = 0.34, 95% CI = 0.17–0.69, p = 0.005). Conclusions This study confirms that insomnia is an independent predictor of suicide attempts in youth with depression. The findings support early identification and intervention for suicidal risk in this vulnerable population.​ Insomnia Suicide attempts Youth Depression Prospective cohort study Figures Figure 1 Figure 2 Figure 3 1 Introduction Depression in youth has emerged as a major global public health concern, with a sharply increasing prevalence and substantial long-term adverse effects on psychosocial functioning and quality of life [ 1 ]. Depression is strongly associated with suicidal behaviors, particularly in young people. In Chinese adolescents with depression, the reported rates of suicidal ideation and suicide attempts are 38.2% and 19.5%, respectively [ 2 , 3 ]. The transition from adolescence to early adulthood is a high-risk period for suicide, which remains a leading cause of death in this age group [ 4 ]. Among individuals with depression, suicide attempts are common and represent one of the strongest predictors of subsequent suicide death, highlighting the need to identify modifiable risk factors in this vulnerable population [ 5 ]. Insomnia represents a common and significant health concern among adolescents. Population-based studies estimate that 20–25% of adolescents report insomnia [ 6 , 7 ]. Among adolescents with depression, the prevalence may be as high as 51% [ 8 ]. Furthermore, insomnia symptoms, short sleep duration, and poor sleep quality have all been associated with increased suicidal ideation and suicide attempts among adolescents and young adults [ 9 – 11 ]. Potential mechanisms include impaired emotion regulation, heightened impulsivity, deficits in decision-making, and dysregulation of circadian rhythms and stress-response systems [ 12 , 13 ]. Because insomnia is treatable, it may serve as a practical target for early suicide prevention. Although insomnia has been linked to suicidality, most existing studies in youth with depression have relied on cross-sectional designs, which limit conclusions about temporal ordering and causality [ 14 – 16 ]. Longitudinal investigations remain limited and have largely focused on suicidal ideation rather than suicide attempts, even though attempts are a more clinically consequential outcome [ 17 , 18 ]. More importantly, prior research has often been constrained by methodological limitations that complicate the interpretation of observed associations. Insomnia is frequently examined as part of composite depression severity measures, making it difficult to determine whether its association with suicidality is independent of overall depressive symptom burden. In addition, inadequate adjustment for baseline clinical risk factors, particularly prior suicide attempts, may result in residual confounding. Collectively, these limitations support prospective studies that establish temporal precedence, minimize measurement overlap, and adjust for key clinical confounders when examining suicide attempts as an outcome. To address these gaps, the present study employed a 6-month prospective cohort study to examine whether insomnia predicts suicide attempts in depressed youth. We used standardized assessments and time-to-event analyses to test whether baseline insomnia severity predicts subsequent suicide attempts after adjusting for depressive and anxiety symptom severity and other clinical factors. By focusing on this high-risk population, our findings can provide valuable insights for interventions targeting insomnia to reduce suicide risk among young adults. 2 Materials and Methods 2.1 Study sample and procedure This study employed a prospective cohort design. From January 2022 to December 2023, participants were consecutively recruited from both the outpatient and inpatient departments of the Affiliated Brain Hospital, Guangzhou Medical University. The study protocol was approved by the Ethics Committee of the Affiliated Brain Hospital, Guangzhou Medical University (Approval No. 2022-031). Written informed consent was obtained from all participants; for minors, consent was additionally obtained from a parent or legal guardian. Young patients receiving treatment at the hospital completed a structured clinical interview during their initial visit, administered by trained psychiatrists. In addition, participants completed self-report questionnaires (described in detail below) and provided sociodemographic information. Following the clinical assessment, the attending psychiatrists established diagnoses and formulated treatment recommendations. Eligible patients and their families were then informed of the study procedures, and written informed consent was obtained from both the patients and their caregivers. Participants subsequently attended follow-up appointments over six months (at 1, 3, and 6 months) and completed the same interviews and questionnaires. Follow-up assessments were conducted by trained clinicians or research staff through face-to-face evaluations, telephone interviews, or online video consultations. For participants who did not complete the follow-up assessments, the reasons for loss to follow-up were documented. The inclusion criteria for this study were: (1) age between 13 and 25 years, defined as youth based on our previous publication [ 16 ]; and (2) meeting the ICD-10 diagnostic criteria for depressive episodes, recurrent depressive disorder, or bipolar disorder currently in a depressive episode. Participants were also required to have at least an elementary-level ability in reading and writing, sufficient comprehension to understand the questionnaires, and the capacity to complete the assessments independently. Exclusion criteria included a history of substance abuse or dependence as defined by ICD-10, schizophrenia spectrum disorders, or severe organic medical conditions. A total of 1,051 patients consented to participate in the cohort study, of whom 839 (79.83%) completed the baseline surveys; ultimately, only 561 participants (53.38%) completed all required follow-up surveys for inclusion in the final analyses. Details are presented in Fig. 1 . 2.2 Measures Insomnia Sleep quality was assessed using the Athens Insomnia Scale (AIS), which has been validated in Chinese populations and demonstrates good reliability and validity [ 19 ]. The AIS consists of eight items: the first five assess difficulties with sleep induction, awakenings during the night, early morning awakening, total sleep duration, and overall sleep quality; the remaining three evaluate the daytime consequences of insomnia, including well-being, functioning, and sleepiness. Each item is rated on a Likert scale ranging from 0 to 3, yielding a total score between 0 and 24. A total AIS score ≥ 6 was defined as insomnia. Previous studies have shown that the AIS consisted of a two-factor structure: “nocturnal sleep problems” (Items 1–5) and “daytime dysfunction” (Items 6–8) [ 20 ]. In the present sample, the internal consistency of the AIS was satisfactory, with a Cronbach’s alpha of 0.856. Depression Depressive symptoms were assessed using the 17-item Hamilton Depression Rating Scale (HAMD-17) [ 21 ], one of the most widely used clinician-rated instruments in depression research. Higher scores reflect greater severity of depressive symptoms. The HAMD-17 captures five symptom domains: retardation, cognitive impairment, anxiety/somatization, sleep disturbance, and weight change [ 22 ]. In accordance with common clinical guidelines, total scores ≤ 7 were considered within the normal range, scores of 17–24 suggested probable depression, and scores ≥ 24 indicated severe depressive symptoms. To avoid construct overlap with sleep measures, the three sleep-related items were excluded from the total score in the present analyses. Anxiety Anxiety symptoms were assessed using the 14-item Hamilton Anxiety Rating Scale (HAMA-14) [ 23 ], a clinician-administered instrument widely used in both clinical and research settings to evaluate the severity of anxiety. The scale consists of two domains: psychic anxiety (e.g., anxious mood, tension, fears, cognitive concerns) and somatic anxiety (e.g., autonomic symptoms, respiratory and cardiovascular complaints). Each item is rated on a 5-point Likert scale, ranging from 0 (not present) to 4 (severe), yielding a total score between 0 and 56. Higher scores indicate more severe anxiety symptoms. In clinical interpretation, scores of 14–20 typically indicate mild anxiety, 21–28 moderate anxiety, and ≥ 29 severe anxiety. The HAMA-14 has demonstrated good reliability and validity in Chinese populations [ 24 ]. Suicide attempts At baseline, participants were asked to report any suicide attempts that occurred during the period in their lifetime when their suicidal tendency was most pronounced. If they provided an affirmative response, additional information, including the method, intent, and total number of attempts, was collected. During follow-up assessments at 1, 3, and 6 months, trained evaluators conducted structured interviews to determine whether any suicidal behaviors had occurred in the preceding month. All assessments were adapted from the Columbia-Suicide Severity Rating Scale (C-SSRS) [ 25 ] to ensure standardized evaluation of suicidal ideation and behavior. To ensure consistency and reliability in ratings throughout the study, all evaluators underwent training in the use of the HAMD, HAMA, and C-SSRS prior to the study. Post-training assessments demonstrated high inter-rater reliability, with correlation coefficients for total scores on the HAMD, HAMA, and C-SSRS all exceeding 0.80. Furthermore, all evaluators were blinded to the clinical status of the patients during the assessment process. 2.3 Statistical analysis Baseline characteristics were summarized using descriptive statistics. Participants were classified into insomnia (AIS ≥ 6) and non-insomnia groups. Normality of continuous variables was examined using the Shapiro–Wilk test; normally distributed variables were presented as mean ± standard deviation (M ± SD), and categorical variables as frequencies and percentages [n (%)]. Between-group differences were assessed using independent t-tests or Mann–Whitney U tests for continuous variables and chi-square tests for categorical variables. Missing data patterns were evaluated using Little’s MCAR test[ 26 ], supplemented by logistic regression to explore associations between missingness and baseline characteristics. Missing data due to attrition were addressed using multiple imputation (m = 5) [ 27 ], with complete-case analyses conducted as sensitivity checks. Time-to-event analyses were performed using Kaplan–Meier curves and log-rank tests. The proportional hazards assumption was evaluated via formal testing; variables violating the assumption were modeled using stratified Cox procedures (categorical variables) or time-dependent interaction terms (continuous variables). Multivariable Cox proportional hazards models were used to examine the prospective association between insomnia and suicide attempts, adjusting for insomnia-corrected HAMD-17 and HAMA-14 total scores, age, sex, and other potential confounders. Predefined subgroup analyses (sex, age, illness duration, episode type, and history of suicide attempts) were conducted using a two-step strategy: unadjusted Cox models within each subgroup, followed by models incorporating interaction terms between the AIS total score and subgroup variables to evaluate effect modification. As supplementary analyses, AIS nighttime symptoms and daytime dysfunction subscale scores were separately entered into Cox models. All analyses were performed using R software (version 4.4.2; R Foundation for Statistical Computing, Vienna, Austria). A two-sided significance level of 0.05 was applied. 3 Results 3.1 Sample characteristics The final analysis included 561 participants who completed all follow-up surveys, of whom 458 (81.6%) met the criteria for insomnia (AIS ≥ 6). The demographic and clinical characteristics of the participants are outlined in Table 1. Compared with the no insomnia group, individuals with insomnia were slightly younger (SMD = 0.348, p = 0.002) and exhibited a substantially higher burden of depressive (SMD = 1.55, p ＜ 0.001) and anxiety (SMD = 1.48, p ＜ 0.001) symptoms. Lifetime suicide attempts were also more frequent in the insomnia group (41.9% vs 28.2%; SMD = 0.29; p = 0.035). As expected, all measures derived from the AIS were significantly elevated in the insomnia group ( p < 0.001 for total and subscale scores). No statistically significant differences were observed between the groups regarding gender, illness duration, episode status, and medication use (all p ＞ 0.05). Table 1. Demographic and Clinical Characteristics of Patients by Insomnia Status Variable No insomnia (n=103) Insomnia (n=458) p SMD Demographic Characteristics Age, years, M (SD) 19.67 (3.11) 18.58 (3.17) 0.002 0.348 Gender, n (%) 0.069 0.205 male 32 (31.1) 101 (22.1) female 71 (68.9) 357 (77.9) Clinical Characteristics Illness duration, n (%) 0.218 0.203 24 months 53 (51.5) 213 (46.5) Episode Status, n (%) 0.976 0.015 First Episode 46 (44.7) 208 (45.4) Recurrent episode 57 (55.3) 250 (54.6) Medication Use, n (%) 0.196 0.165 Yes 91 (88.3) 378 (82.5) No 12 (11.7) 80 (17.5) Lifetime Suicide Attempt, n (%) 0.035 0.293 None 74 (71.8) 266 (58.1) 1–2 times 20 (19.4) 128 (27.9) ≥ 3 times 9 (8.7) 64 (14.0) HAMD-17, M (SD) 10.82 (6.40) 20.82 (6.51) <0.001 1.548 HAMA-14, M (SD) 11.09 (6.65) 22.05 (8.10) <0.001 1.481 AIS, M (SD) 3.41 (1.58) 12.70 (4.28) <0.001 2.881 AIS-Nocturnal, M (SD) 1.77 (1.24) 7.61 (3.47) <0.001 2.24 AIS-Daytime, M (SD) 1.64 (1.19) 5.09 (1.77) <0.001 2.292 Note. HAMD-17: 17-item Hamilton Depression Rating Scale; HAMA-14: 14-item Hamilton Anxiety Rating Scale; AIS: Athens Insomnia Scale; C-SSRS: Columbia-Suicide Severity Rating Scale; SMD: Standard Mean Difference; Bold text is used to indicate statistically significant results. 3.2 Suicide attempt during follow-up Across the three follow–up assessments, the extent of missing data increased over time (See Supplementary Fig. 1). Follow–up data were complete at the 1-month assessment, whereas 86 cases (15.3%) were missing at 3 months and 162 cases (28.9%) at 6 months, with multiple combined missingness patterns observed across time points. As shown in Table 2. Group differences in suicide attempts emerged only in the first month. Participants with insomnia showed a higher 1-month suicide attempt rate compared with those without insomnia (6.6% vs 1.0%; SMD = 0.30; p = 0.045). No significant between-group differences were observed during months 1–3 or months 3–6 (all p ≥ 0.05), although numerically higher rates persisted in the insomnia group. Table 2. Suicide Attempt during Follow-up Variable No insomnia Insomnia p SMD Suicide attempt Month 0–1, n (%) 0.045 0.296 Yes 1 (1.0) 30 (6.6) No 102 (99.0) 428 (93.4) Suicide attempt Month 1–3, n (%) 0.623 0.095 Yes 3 (3.3) 20 (5.2) No 88 (96.7) 364 (94.8) Suicide attempt Month 3–6, n (%) 0.050 0.317 Yes 2 (2.5) 32 (10.1) No 79 (97.5) 286 (89.9) 3.3 Missing Data Mechanism Little’s test indicated that the missing data were not completely at random ( p < 0.001). Logistic regression analyses further showed that missingness at the 1–3 month and 3–6 month assessments was significantly associated with age, illness duration, recurrence, and suicide attempt ＞ 3 times (Supplementary Table 1). These findings support the assumption that the missing data mechanism was consistent with missing at random (MAR). Therefore, multiple imputation was applied to handle missing values, and complete-case analyses were conducted as sensitivity checks. 3.4 Survival Analysis of Suicide Attempt Risk by Insomnia Status Kaplan–Meier curves showed that participants with insomnia experienced a significantly higher risk of suicide attempt over the 6-month follow-up compared with those without insomnia (log-rank p ＜ 0.001; Fig. 2). Consistent with this pattern, Cox regression indicated that insomnia severity independently predicted increased risk of suicide attempt (HR = 1.07, 95% CI: 1.01–1.13, p = 0.038) after adjustment for covariates. Greater depressive severity and prior suicide attempts were also significant predictors, whereas longer illness duration (> 24 months) was associated with reduced risk. Complete case analyses yielded similar results (Table 3). 3.5 Subgroup Analysis of the Association Between Insomnia Severity and Suicide Attempt Risk Across all predefined subgroups, the positive association between AIS scores and suicide attempt risk remained highly consistent (Fig. 3). HR estimates clustered around 1.1 across gender, age, episode status, medication use, illness duration, and suicide history, indicating a stable effect size with no evidence of effect modification (all interaction p > 0.05). These findings align with the primary Cox model results and suggest that the impact of insomnia severity on suicide risk is broadly comparable across patient subgroups. 3.6 Supplementary Analysis: Insomnia Dimensions In models separating nocturnal symptoms and daytime dysfunction (Supplementary Table 2), neither dimension independently predicted suicide attempts after adjustment (AIS-Nocturnal: HR = 1.06, 95% CI: 0.99–1.13; p = 0.11; AIS-Daytime: HR = 1.09, 95% CI: 0.94–1.25; p = 0.25). Depressive severity and suicide history remained significant predictors, while longer illness duration was associated with lower risk. These results suggest that no single insomnia dimension accounts for the association observed for overall AIS scores in the primary analysis. 4 Discussion We investigated the prospective association between insomnia severity and subsequent suicide attempts in depressed youth using a 6-month observational longitudinal design in a psychiatric sample. Our results showed that greater baseline insomnia severity was associated with a higher risk of suicide attempts during follow-up, and this association remained after accounting for key clinical factors. The findings were also consistent in sensitivity analyses, supporting the robustness of the main inference. Our results extend the literature by demonstrating a prospective link between insomnia and suicide attempts in clinically depressed youth, using time-to-event modeling and rigorous adjustment for key clinical confounders, including depression and anxiety severity, after removing overlapping sleep items. Notably, the present prospective results also align with and extend our prior cross-sectional evidence suggesting that sleep disturbance impairment is closely linked to suicidality in depressed youth [ 16 ]. Our findings are consistent with evidence from recent longitudinal research. A 6-month follow-up study of 782 middle school students reported that insomnia was an independent predictor of suicide attempts (OR = 6.00) [ 28 ]. Similar patterns have been observed in population-based research[ 11 ]. However, it is important to recognize that the above studies were conducted in community-based school samples rather than clinically diagnosed depressed populations, and suicidal outcomes were typically measured using self-report questionnaires or single-item assessments. Such measurement approaches may be vulnerable to recall bias and outcome misclassification, and they do not capture the timing of suicidal behaviors, limiting inference about near-term risk. In contrast, our study focused on treatment-seeking youth with depressive episodes and used repeated assessments over follow-up with time-to-event modeling, thereby providing clinically grounded evidence that insomnia severity confers incremental prognostic value for subsequent suicide attempts beyond overall symptom severity. In addition to insomnia, more severe depressive symptoms and a history of suicide attempts were strong predictors of suicide attempts during follow-up in our cohort. This pattern is consistent with evidence from cohort-based meta-analyses in depressive disorders, which identify greater illness severity and prior suicidal behavior as reliable risk markers for later suicide attempts [ 29 ]. It also fits with prospective findings in clinically depressed adolescents, where baseline suicidal risk indicators predict later attempts [ 30 ]. In contrast, a longer illness duration (> 24 months) was associated with a lower risk in our sample. This finding differs from some previous studies, which reported that longer illness duration was associated with a higher risk of suicide attempts [ 31 , 32 ]. This result should be interpreted with caution. One possible explanation is that suicide attempts may occur more often earlier in the course for some patients, and those who remain in long-term care may receive more monitoring and treatment. Long-term follow-up data in severe depression also suggest that attempt risk can decrease with more years spent depressed, which is broadly consistent with this idea [ 33 ]. Therefore, the direction of this association remains unclear and should be tested again in youth clinical cohorts. In supplementary analyses, separating insomnia into nocturnal symptoms and daytime dysfunction did not show statistically significant associations with suicide attempts after covariate adjustment when both components were entered in the same model. This pattern is plausible because insomnia is widely conceptualized as a 24-hour disorder, in which daytime impairment is not merely a consequence but a defining feature of the condition [ 34 ]. The AIS was also developed to capture this combined burden, and its two-factor structure (nocturnal problems and daytime dysfunction) does not imply that these domains operate independently in clinical risk [ 20 ]. In adolescents, prior longitudinal work further suggests that daytime sleepiness can sit on the pathway between insomnia symptoms and subsequent suicidal behavior, supporting an integrated view of nighttime sleep problems and daytime functioning [ 35 ]. Methodologically, nocturnal and daytime subscales are correlated, so including both may reduce the unique information carried by each and weaken statistical signals. Overall, our findings suggest that the AIS total score may better reflect clinically relevant sleep-related risk than either domain alone in this cohort. The causal relationship between sleep disturbance and suicidal behavior in depression remains unclear. Prior studies have proposed several hypotheses that may help explain the underlying mechanisms. Behaviourally, insufficient sleep impairs emotion regulation and heightens negative affect in youth [ 36 ]. Acute sleep loss amplifies emotional reactivity; adolescents show poor inhibition of negative emotions, reduced positive affect [ 37 ], and greater rumination or distress [ 38 ]. During adolescence, when fronto-limbic circuits are still maturing, chronic sleep loss may undermine prefrontal inhibitory control and decision-making [ 39 ]. Neuroimaging researches show sleep deprivation weakens prefrontal–amygdala connectivity and shifts activity toward brainstem and limbic regions [ 40 ], consistent with greater impulsivity and risk-taking in sleep-restricted youth. Biologically, adolescent circadian delays and “social jetlag” magnify this vulnerability: misalignment of the sleep–wake cycle produces daytime sleepiness and mood swings that exacerbate emotional lability [ 41 ]. At the neurochemical level, chronic insomnia may dysregulate serotonin and other modulators of mood and arousal, compromising impulse control and mood stability[ 42 ]. In sum, insomnia may amplify suicide risk in depressed teens by degrading affect regulation and executive control via disrupted neural circuits (e.g., prefrontal-amygdala pathways) and desynchronizing circadian-mood biology. These mechanistic insights underscore why treating sleep problems in youth depression is vital for suicide prevention. This study has several strengths. By focusing on treatment-seeking adolescents and young adults with depressive disorder, a clinically high-risk population in which sleep disturbances are common, and suicide prevention is a central concern. The prospective cohort design, standardized suicidality assessments, and repeated follow-ups over 6 months allowed us to capture the timing of suicide attempts and model risk over time. This framework supported the use of time-to-event models, which are well-suited to uneven follow-up and censored outcomes. In addition, we reduced potential measurement overlap by excluding sleep-related items from the depression and anxiety scales, which helped isolate the contribution of insomnia severity beyond overall symptom burden. Finally, we addressed incomplete follow-up using multiple imputation and confirmed the main findings with complete-case sensitivity analyses, strengthening confidence in the robustness of the results. Nevertheless, several limitations deserve further discussion. First, the cohort was recruited from a single psychiatric hospital, which may limit generalizability to community samples or to patients in other care settings. Second, insomnia was measured using a self-report scale rather than objective sleep metrics (e.g., actigraphy or polysomnography), so misclassification is possible. Third, follow-up missingness increased over time. Although we used multiple imputation and confirmed the results in complete-case analyses, bias due to unmeasured factors related to attrition may remain. Finally, the follow-up period was limited to 6 months, and we did not model time-varying changes in treatment or symptoms. Longer follow-up and repeated sleep assessments will be important to clarify longer-term risk and potential mechanisms. 5 Conclusion In this 6-month prospective cohort study of youth with depression, greater baseline insomnia severity was associated with a higher risk of subsequent suicide attempts, independent of depressive and anxiety symptom severity and other key clinical factors. These findings suggested that insomnia has meaningful short-term implications for suicidal risk in depressed youth and highlight the potential value of improving sleep assessment and management as part of early risk stratification and suicide prevention in this high-risk population. Declarations Acknowledgments The authors thank all participants for their time and contribution to this study. All authors also acknowledge the research staff and scientific advisors for their valuable input to the study design. Funding Sources This work was supported by the Natural Science Foundation Program of Guangdong (2024A1515013133), the Joint Funding Program by Guangzhou Science and Technology Bureau and Local Universities/Institutions/Enterprises (Project No. 2023A03J0844, 2023A03J0434, 2023A03J0845), and the Guangzhou Key Laboratory of Psychosomatic Medicine (Project No. SL2023A03J00421). Competing interests We declare no competing interests. Ethical Standards All authors assert that this study was performed in accordance with the institutional research ethics guidelines and the Helsinki Declaration. This study was approved by the Ethics Committee of the Affiliated Brain Hospital of Guangzhou Medical University. Consent for publication Not applicable. Availability of data and materials Due to privacy restrictions related to patient data, the datasets generated and/or analyzed during the current study are not publicly available. However, they can be obtained from the corresponding author upon reasonable request. Author Contributions Xuefei Fan: Writing–original draft, Supervision, Methodology, Investigation, Formal analysis. Kunrong Lin: Writing–original draft, Supervision, Methodology, Investigation, Formal analysis. Ziyan Zhou: Writing–original draft, Formal analysis, Data curation. Yarong Ma: Data curation, Formal analysis, Writing. Lin Xiaoming: Resources, Investigation, Formal analysis. 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Chung K-F, Kan KK-K, Yeung W-F. Assessing insomnia in adolescents: comparison of Insomnia Severity Index, Athens Insomnia Scale and Sleep Quality Index. Sleep Med 2011;12:463–70. https://doi.org/10.1016/j.sleep.2010.09.019. Okajima I, Nakajima S, Kobayashi M, Inoue Y. Development and validation of the Japanese version of the Athens Insomnia Scale. Psychiatry Clin Neurosci 2013;67:420–5. https://doi.org/10.1111/pcn.12073. Hamilton M. A rating scale for depression. J Neurol Neurosurg Psychiatry 1960;23:56–62. https://doi.org/10.1136/jnnp.23.1.56. Zhao B, Li Z, Wang Y, Ma X, Wang X, Wang X, et al. Can acupuncture combined with SSRIs improve clinical symptoms and quality of life in patients with depression? Secondary outcomes of a pragmatic randomized controlled trial. Complement Ther Med. 2019;45:295–302. https://doi.org/10.1016/j.ctim.2019.03.015. Hamilton M. The assessment of anxiety states by rating. Br J Med Psychol 1959;32:50–5. https://doi.org/10.1111/j.2044-8341.1959.tb00467.x. 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The association between insomnia and suicide attempts among Chinese adolescents: a prospective cohort study. BMC Psychol 2024;12:777. https://doi.org/10.1186/s40359-024-02273-9. Li X, Mu F, Liu D, Zhu J, Yue S, Liu M, et al. Predictors of suicidal ideation, suicide attempt and suicide death among people with major depressive disorder: A systematic review and meta-analysis of cohort studies. Journal of Affective Disorders 2022;302:332–51. https://doi.org/10.1016/j.jad.2022.01.103. Wilkinson P, Kelvin R, Roberts C, Dubicka B, Goodyer I. Clinical and psychosocial predictors of suicide attempts and nonsuicidal self-injury in the Adolescent Depression Antidepressants and Psychotherapy Trial (ADAPT). Am J Psychiatry 2011;168:495–501. https://doi.org/10.1176/appi.ajp.2010.10050718. Song X, Liu X, Zhou Y, Zhang X. Prevalence and correlates of suicide attempts in young patients with first-episode and drug-naïve major depressive disorder: A large cross-sectional study. J Affect Disord 2023;340:340–6. https://doi.org/10.1016/j.jad.2023.08.006. Zhou Y, Ren W, Sun Q, Yu KM, Lang X, Li Z, et al. The association of clinical correlates, metabolic parameters, and thyroid hormones with suicide attempts in first-episode and drug-naïve patients with major depressive disorder comorbid with anxiety: a large-scale cross-sectional study. Transl Psychiatry 2021;11:97. https://doi.org/10.1038/s41398-021-01234-9. Crona L, Mossberg A, Brådvik L. Suicidal Career in Severe Depression among Long-Term Survivors: In a Followup after 37-53 Years Suicide Attempts Appeared to End Long before Depression. Depress Res Treat 2013;2013:610245. https://doi.org/10.1155/2013/610245. Morin CM, Chen S-J, Ivers H, Beaulieu-Bonneau S, Krystal AD, Guay B, et al. Effect of Psychological and Medication Therapies for Insomnia on Daytime Functions: A Randomized Clinical Trial. JAMA Netw Open 2023;6:e2349638. https://doi.org/10.1001/jamanetworkopen.2023.49638. Liu Z-Z, Jia C-X, Liu X. Excessive daytime sleepiness mediates the relationship between insomnia symptoms and suicidal behavior in adolescents. Sleep 2022;45:zsac221. https://doi.org/10.1093/sleep/zsac221. Lima Santos JP, Pachgade M, Soehner AM. Slow Wave Sleep and Emotion Regulation in Adolescents With Depressive Symptoms: An Experimental Pilot Study. J Sleep Res 2025;34:e70038. https://doi.org/10.1111/jsr.70038. Tomaso CC, Johnson AB, Nelson TD. The effect of sleep deprivation and restriction on mood, emotion, and emotion regulation: three meta-analyses in one. Sleep 2021;44:zsaa289. https://doi.org/10.1093/sleep/zsaa289. Uccella S, Cordani R, Salfi F, Gorgoni M, Scarpelli S, Gemignani A, et al. Sleep Deprivation and Insomnia in Adolescence: Implications for Mental Health. Brain Sci. 2023;13(4):569. https://doi.org/10.3390/brainsci13040569. Pawley M, Morales-Muñoz I, Bagshaw AP, Tang NKY. Sleep problems, decision-making, and suicide attempts during adolescence: a longitudinal birth cohort study. Sleep Adv 2025;6:zpaf062. https://doi.org/10.1093/sleepadvances/zpaf062. Jamieson D, Broadhouse KM, Lagopoulos J, Hermens DF. Investigating the links between adolescent sleep deprivation, fronto-limbic connectivity and the Onset of Mental Disorders: a review of the literature. Sleep Med 2020;66:61–7. https://doi.org/10.1016/j.sleep.2019.08.013. Rolling J, Ligier F, Rabot J, Bourgin P, Reynaud E, Schroder CM. Sleep and circadian rhythms in adolescents with attempted suicide. Sci Rep 2024;14:8354. https://doi.org/10.1038/s41598-024-57921-2. Blake MJ, Trinder JA, Allen NB. Mechanisms underlying the association between insomnia, anxiety, and depression in adolescence: Implications for behavioral sleep interventions. Clin Psychol Rev 2018;63:25–40. https://doi.org/10.1016/j.cpr.2018.05.006. Additional Declarations No competing interests reported. Supplementary Files SupplementaryMaterials.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 29 Apr, 2026 Reviews received at journal 27 Apr, 2026 Reviews received at journal 26 Apr, 2026 Reviews received at journal 20 Apr, 2026 Reviewers agreed at journal 13 Apr, 2026 Reviewers agreed at journal 02 Apr, 2026 Reviewers agreed at journal 31 Mar, 2026 Reviewers invited by journal 31 Mar, 2026 Editor assigned by journal 24 Mar, 2026 Submission checks completed at journal 21 Mar, 2026 First submitted to journal 17 Mar, 2026 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. 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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-9144236","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":616875288,"identity":"63ae5626-9f4a-4052-ad67-2c3598569f6f","order_by":0,"name":"Xuefei Fan","email":"","orcid":"","institution":"Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xuefei","middleName":"","lastName":"Fan","suffix":""},{"id":616875289,"identity":"9f672cae-8fdb-4600-81cf-61162b5f46d8","order_by":1,"name":"Kunrong Lin","email":"","orcid":"","institution":"The Affiliated Brain Hospital, Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Kunrong","middleName":"","lastName":"Lin","suffix":""},{"id":616875290,"identity":"b3bc2c7a-3c68-4278-8f18-1ceb40ba6f4d","order_by":2,"name":"Ziyan Zhou","email":"","orcid":"","institution":"Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University","correspondingAuthor":false,"prefix":"","firstName":"Ziyan","middleName":"","lastName":"Zhou","suffix":""},{"id":616875300,"identity":"4d6f9d9c-f9bb-42c7-ac14-fdfe25180bc4","order_by":3,"name":"Xiaoming Lin","email":"","orcid":"","institution":"South China Hospital, Medical School, Shenzhen University","correspondingAuthor":false,"prefix":"","firstName":"Xiaoming","middleName":"","lastName":"Lin","suffix":""},{"id":616875306,"identity":"79751d48-6c82-4b0f-8639-dcdd5f233df5","order_by":4,"name":"Yarong Ma","email":"","orcid":"","institution":"Shenzhen Second People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yarong","middleName":"","lastName":"Ma","suffix":""},{"id":616875307,"identity":"3cef42e5-120e-4e90-a274-31d11cbc8a40","order_by":5,"name":"Jie Zhang","email":"","orcid":"","institution":"The Affiliated Brain Hospital, Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jie","middleName":"","lastName":"Zhang","suffix":""},{"id":616875309,"identity":"fe7af75c-b0c9-491f-ae00-baa3f293db7b","order_by":6,"name":"Hongbo He","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAtElEQVRIiWNgGAWjYFAC5gYGhgobHn72BqK1MDYwHDiTJiPZc4AULQfbDtsY3HAgUoPB+YVt0h/YzvMw3GBg/PAxhxgtNx62SRzguc3DOLuBWXLmNiK0SM44CNQicZuHWeYAGzMv8VoMzvGwSSQQqYWfvxGoJeEADw/xWiQYmy3OHEjmkeA52EycX9j4Dx+8UfnPzt7+ePPBDx+J0cIgkQBjASOIOMB/gEiFo2AUjIJRMHIBAADjN6nD/sc+AAAAAElFTkSuQmCC","orcid":"","institution":"Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University","correspondingAuthor":true,"prefix":"","firstName":"Hongbo","middleName":"","lastName":"He","suffix":""}],"badges":[],"createdAt":"2026-03-17 05:23:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9144236/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9144236/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106206365,"identity":"2d380a48-98ea-4cb9-beac-a37a927ec3e8","added_by":"auto","created_at":"2026-04-06 05:43:42","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":102332,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart for the inclusion of participants\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9144236/v1/b4acffed6183090f7012cc3f.png"},{"id":106403283,"identity":"1f33b353-e72a-4003-a029-efd6d07fb4b0","added_by":"auto","created_at":"2026-04-08 09:14:00","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":110849,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan–Meier survival curves for the first suicide attempt during the 6-month follow-up according to the presence of insomnia. Survival probabilities over the follow-up period are shown for each group. Shaded areas indicate 95% confidence intervals. The number of participants at risk at each time point is displayed below the curves. The log-rank test was used to compare survival between groups, and the corresponding p-value is shown on the plot. Data are based on the first imputed dataset (n = 561) using multiple imputation by chained equations.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9144236/v1/2337b6759ebe02abd45c28e5.png"},{"id":106402244,"identity":"6d53df1e-990c-4425-9ec2-fec0171ecceb","added_by":"auto","created_at":"2026-04-08 09:11:31","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":300215,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot of hazard ratios for suicide attempt according to AIS. Notes: Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models without adjustment for covariates. N total indicates the number of participants in each subgroup, and N event represents the number of participants who experienced at least one suicide attempt during the follow-up period. Interaction P values indicate the significance of the interaction between the AIS total score and subgroup variables on suicidal attempt risk.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9144236/v1/d6c80065c6b301189b9d0cf9.png"},{"id":106405829,"identity":"0204d2d3-4778-4a0a-80b9-fdc375292e8a","added_by":"auto","created_at":"2026-04-08 09:28:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1283746,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9144236/v1/3b8b3ce4-ca81-42ba-b764-588c40c9e594.pdf"},{"id":106402896,"identity":"ebdc60be-e28d-478c-a046-bcda497441f0","added_by":"auto","created_at":"2026-04-08 09:13:09","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":73167,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-9144236/v1/0509c2c1cdbd46b79d9f558f.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Insomnia Severity Predicts Suicide Attempts in Youth with depression: A 6-Month Prospective Cohort Study","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eDepression in youth has emerged as a major global public health concern, with a sharply increasing prevalence and substantial long-term adverse effects on psychosocial functioning and quality of life [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Depression is strongly associated with suicidal behaviors, particularly in young people. In Chinese adolescents with depression, the reported rates of suicidal ideation and suicide attempts are 38.2% and 19.5%, respectively [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The transition from adolescence to early adulthood is a high-risk period for suicide, which remains a leading cause of death in this age group [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Among individuals with depression, suicide attempts are common and represent one of the strongest predictors of subsequent suicide death, highlighting the need to identify modifiable risk factors in this vulnerable population [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eInsomnia represents a common and significant health concern among adolescents. Population-based studies estimate that 20\u0026ndash;25% of adolescents report insomnia [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Among adolescents with depression, the prevalence may be as high as 51% [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Furthermore, insomnia symptoms, short sleep duration, and poor sleep quality have all been associated with increased suicidal ideation and suicide attempts among adolescents and young adults [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Potential mechanisms include impaired emotion regulation, heightened impulsivity, deficits in decision-making, and dysregulation of circadian rhythms and stress-response systems [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Because insomnia is treatable, it may serve as a practical target for early suicide prevention.\u003c/p\u003e \u003cp\u003eAlthough insomnia has been linked to suicidality, most existing studies in youth with depression have relied on cross-sectional designs, which limit conclusions about temporal ordering and causality [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Longitudinal investigations remain limited and have largely focused on suicidal ideation rather than suicide attempts, even though attempts are a more clinically consequential outcome [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. More importantly, prior research has often been constrained by methodological limitations that complicate the interpretation of observed associations. Insomnia is frequently examined as part of composite depression severity measures, making it difficult to determine whether its association with suicidality is independent of overall depressive symptom burden. In addition, inadequate adjustment for baseline clinical risk factors, particularly prior suicide attempts, may result in residual confounding. Collectively, these limitations support prospective studies that establish temporal precedence, minimize measurement overlap, and adjust for key clinical confounders when examining suicide attempts as an outcome.\u003c/p\u003e \u003cp\u003eTo address these gaps, the present study employed a 6-month prospective cohort study to examine whether insomnia predicts suicide attempts in depressed youth. We used standardized assessments and time-to-event analyses to test whether baseline insomnia severity predicts subsequent suicide attempts after adjusting for depressive and anxiety symptom severity and other clinical factors. By focusing on this high-risk population, our findings can provide valuable insights for interventions targeting insomnia to reduce suicide risk among young adults.\u003c/p\u003e"},{"header":"2 Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Study sample and procedure\u003c/h2\u003e \u003cp\u003eThis study employed a prospective cohort design. From January 2022 to December 2023, participants were consecutively recruited from both the outpatient and inpatient departments of the Affiliated Brain Hospital, Guangzhou Medical University. The study protocol was approved by the Ethics Committee of the Affiliated Brain Hospital, Guangzhou Medical University (Approval No. 2022-031). Written informed consent was obtained from all participants; for minors, consent was additionally obtained from a parent or legal guardian.\u003c/p\u003e \u003cp\u003eYoung patients receiving treatment at the hospital completed a structured clinical interview during their initial visit, administered by trained psychiatrists. In addition, participants completed self-report questionnaires (described in detail below) and provided sociodemographic information. Following the clinical assessment, the attending psychiatrists established diagnoses and formulated treatment recommendations. Eligible patients and their families were then informed of the study procedures, and written informed consent was obtained from both the patients and their caregivers. Participants subsequently attended follow-up appointments over six months (at 1, 3, and 6 months) and completed the same interviews and questionnaires. Follow-up assessments were conducted by trained clinicians or research staff through face-to-face evaluations, telephone interviews, or online video consultations. For participants who did not complete the follow-up assessments, the reasons for loss to follow-up were documented.\u003c/p\u003e \u003cp\u003eThe inclusion criteria for this study were: (1) age between 13 and 25 years, defined as youth based on our previous publication [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]; and (2) meeting the ICD-10 diagnostic criteria for depressive episodes, recurrent depressive disorder, or bipolar disorder currently in a depressive episode. Participants were also required to have at least an elementary-level ability in reading and writing, sufficient comprehension to understand the questionnaires, and the capacity to complete the assessments independently. Exclusion criteria included a history of substance abuse or dependence as defined by ICD-10, schizophrenia spectrum disorders, or severe organic medical conditions. A total of 1,051 patients consented to participate in the cohort study, of whom 839 (79.83%) completed the baseline surveys; ultimately, only 561 participants (53.38%) completed all required follow-up surveys for inclusion in the final analyses. Details are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Measures\u003c/h2\u003e \u003cp\u003e \u003cem\u003eInsomnia\u003c/em\u003e \u003c/p\u003e \u003cp\u003eSleep quality was assessed using the Athens Insomnia Scale (AIS), which has been validated in Chinese populations and demonstrates good reliability and validity [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The AIS consists of eight items: the first five assess difficulties with sleep induction, awakenings during the night, early morning awakening, total sleep duration, and overall sleep quality; the remaining three evaluate the daytime consequences of insomnia, including well-being, functioning, and sleepiness. Each item is rated on a Likert scale ranging from 0 to 3, yielding a total score between 0 and 24. A total AIS score\u0026thinsp;\u0026ge;\u0026thinsp;6 was defined as insomnia. Previous studies have shown that the AIS consisted of a two-factor structure: \u0026ldquo;nocturnal sleep problems\u0026rdquo; (Items 1\u0026ndash;5) and \u0026ldquo;daytime dysfunction\u0026rdquo; (Items 6\u0026ndash;8) [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In the present sample, the internal consistency of the AIS was satisfactory, with a Cronbach\u0026rsquo;s alpha of 0.856.\u003c/p\u003e \u003cp\u003e \u003cem\u003eDepression\u003c/em\u003e \u003c/p\u003e \u003cp\u003eDepressive symptoms were assessed using the 17-item Hamilton Depression Rating Scale (HAMD-17) [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], one of the most widely used clinician-rated instruments in depression research. Higher scores reflect greater severity of depressive symptoms. The HAMD-17 captures five symptom domains: retardation, cognitive impairment, anxiety/somatization, sleep disturbance, and weight change [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. In accordance with common clinical guidelines, total scores\u0026thinsp;\u0026le;\u0026thinsp;7 were considered within the normal range, scores of 17\u0026ndash;24 suggested probable depression, and scores\u0026thinsp;\u0026ge;\u0026thinsp;24 indicated severe depressive symptoms. To avoid construct overlap with sleep measures, the three sleep-related items were excluded from the total score in the present analyses.\u003c/p\u003e \u003cp\u003e \u003cem\u003eAnxiety\u003c/em\u003e \u003c/p\u003e \u003cp\u003eAnxiety symptoms were assessed using the 14-item Hamilton Anxiety Rating Scale (HAMA-14) [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], a clinician-administered instrument widely used in both clinical and research settings to evaluate the severity of anxiety. The scale consists of two domains: psychic anxiety (e.g., anxious mood, tension, fears, cognitive concerns) and somatic anxiety (e.g., autonomic symptoms, respiratory and cardiovascular complaints). Each item is rated on a 5-point Likert scale, ranging from 0 (not present) to 4 (severe), yielding a total score between 0 and 56. Higher scores indicate more severe anxiety symptoms. In clinical interpretation, scores of 14\u0026ndash;20 typically indicate mild anxiety, 21\u0026ndash;28 moderate anxiety, and \u0026ge;\u0026thinsp;29 severe anxiety. The HAMA-14 has demonstrated good reliability and validity in Chinese populations [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cem\u003eSuicide attempts\u003c/em\u003e \u003c/p\u003e \u003cp\u003eAt baseline, participants were asked to report any suicide attempts that occurred during the period in their lifetime when their suicidal tendency was most pronounced. If they provided an affirmative response, additional information, including the method, intent, and total number of attempts, was collected. During follow-up assessments at 1, 3, and 6 months, trained evaluators conducted structured interviews to determine whether any suicidal behaviors had occurred in the preceding month. All assessments were adapted from the Columbia-Suicide Severity Rating Scale (C-SSRS) [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] to ensure standardized evaluation of suicidal ideation and behavior.\u003c/p\u003e \u003cp\u003eTo ensure consistency and reliability in ratings throughout the study, all evaluators underwent training in the use of the HAMD, HAMA, and C-SSRS prior to the study. Post-training assessments demonstrated high inter-rater reliability, with correlation coefficients for total scores on the HAMD, HAMA, and C-SSRS all exceeding 0.80. Furthermore, all evaluators were blinded to the clinical status of the patients during the assessment process.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Statistical analysis\u003c/h2\u003e \u003cp\u003eBaseline characteristics were summarized using descriptive statistics. Participants were classified into insomnia (AIS\u0026thinsp;\u0026ge;\u0026thinsp;6) and non-insomnia groups. Normality of continuous variables was examined using the Shapiro\u0026ndash;Wilk test; normally distributed variables were presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (M\u0026thinsp;\u0026plusmn;\u0026thinsp;SD), and categorical variables as frequencies and percentages [n (%)]. Between-group differences were assessed using independent t-tests or Mann\u0026ndash;Whitney U tests for continuous variables and chi-square tests for categorical variables.\u003c/p\u003e \u003cp\u003eMissing data patterns were evaluated using Little\u0026rsquo;s MCAR test[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], supplemented by logistic regression to explore associations between missingness and baseline characteristics. Missing data due to attrition were addressed using multiple imputation (m\u0026thinsp;=\u0026thinsp;5) [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], with complete-case analyses conducted as sensitivity checks.\u003c/p\u003e \u003cp\u003eTime-to-event analyses were performed using Kaplan\u0026ndash;Meier curves and log-rank tests. The proportional hazards assumption was evaluated via formal testing; variables violating the assumption were modeled using stratified Cox procedures (categorical variables) or time-dependent interaction terms (continuous variables). Multivariable Cox proportional hazards models were used to examine the prospective association between insomnia and suicide attempts, adjusting for insomnia-corrected HAMD-17 and HAMA-14 total scores, age, sex, and other potential confounders.\u003c/p\u003e \u003cp\u003ePredefined subgroup analyses (sex, age, illness duration, episode type, and history of suicide attempts) were conducted using a two-step strategy: unadjusted Cox models within each subgroup, followed by models incorporating interaction terms between the AIS total score and subgroup variables to evaluate effect modification. As supplementary analyses, AIS nighttime symptoms and daytime dysfunction subscale scores were separately entered into Cox models.\u003c/p\u003e \u003cp\u003eAll analyses were performed using R software (version 4.4.2; R Foundation for Statistical Computing, Vienna, Austria). A two-sided significance level of 0.05 was applied.\u003c/p\u003e \u003c/div\u003e"},{"header":"3 Results","content":"\u003cp\u003e\u003cstrong\u003e3.1 Sample characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe final analysis included 561 participants who completed all follow-up surveys, of whom 458 (81.6%) met the criteria for insomnia (AIS \u0026ge; 6). The demographic and clinical characteristics of the participants are outlined in Table 1. Compared with the no insomnia group, individuals with insomnia were slightly younger (SMD = 0.348, \u003cem\u003ep\u003c/em\u003e = 0.002) and exhibited a substantially higher burden of depressive (SMD = 1.55, \u003cem\u003ep\u003c/em\u003e ＜\u0026nbsp;0.001) and anxiety (SMD = 1.48, \u003cem\u003ep\u003c/em\u003e ＜\u0026nbsp;0.001) symptoms. Lifetime suicide attempts were also more frequent in the insomnia group (41.9% vs 28.2%; SMD = 0.29; \u003cem\u003ep\u003c/em\u003e = 0.035). As expected, all measures derived from the AIS were significantly elevated in the insomnia group (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001 for total and subscale scores).\u0026nbsp;No statistically significant differences were observed between the groups regarding gender, illness duration, episode status, and medication use (all \u003cem\u003ep\u003c/em\u003e ＞\u0026nbsp;0.05).\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 1. Demographic and Clinical Characteristics of Patients by Insomnia Status\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNo\u0026nbsp;insomnia (n=103)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eInsomnia (n=458)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSMD\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eDemographic\u0026nbsp;Characteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eAge,\u0026nbsp;years,\u0026nbsp;M\u0026nbsp;(SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e19.67\u0026nbsp;(3.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e18.58\u0026nbsp;(3.17)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.348\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eGender,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.069\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.205\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; male\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e32\u0026nbsp;(31.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e101\u0026nbsp;(22.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; female\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e71\u0026nbsp;(68.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e357\u0026nbsp;(77.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eClinical\u0026nbsp;Characteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eIllness\u0026nbsp;duration,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.218\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.203\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026lt;6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e11\u0026nbsp;(10.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e81\u0026nbsp;(17.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; 6\u0026ndash;24 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e39\u0026nbsp;(37.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e164\u0026nbsp;(35.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026gt;24 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e53\u0026nbsp;(51.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e213\u0026nbsp;(46.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eEpisode\u0026nbsp;Status,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.976\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.015\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; First Episode\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e46\u0026nbsp;(44.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e208\u0026nbsp;(45.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Recurrent episode\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e57\u0026nbsp;(55.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e250\u0026nbsp;(54.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eMedication\u0026nbsp;Use,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.196\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.165\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e91\u0026nbsp;(88.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e378\u0026nbsp;(82.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e12\u0026nbsp;(11.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e80\u0026nbsp;(17.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eLifetime\u0026nbsp;Suicide\u0026nbsp;Attempt,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.035\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e0.293\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; None\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e74\u0026nbsp;(71.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e266\u0026nbsp;(58.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; 1\u0026ndash;2\u0026nbsp;times\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e20\u0026nbsp;(19.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e128\u0026nbsp;(27.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026ge; 3 times\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e9\u0026nbsp;(8.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e64\u0026nbsp;(14.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eHAMD-17,\u0026nbsp;M\u0026nbsp;(SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e10.82\u0026nbsp;(6.40)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e20.82\u0026nbsp;(6.51)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1.548\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eHAMA-14,\u0026nbsp;M\u0026nbsp;(SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e11.09\u0026nbsp;(6.65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e22.05\u0026nbsp;(8.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1.481\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eAIS,\u0026nbsp;M\u0026nbsp;(SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e3.41\u0026nbsp;(1.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e12.70\u0026nbsp;(4.28)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2.881\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eAIS-Nocturnal,\u0026nbsp;M\u0026nbsp;(SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1.77\u0026nbsp;(1.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e7.61\u0026nbsp;(3.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2.24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003eAIS-Daytime,\u0026nbsp;M\u0026nbsp;(SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e1.64\u0026nbsp;(1.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e5.09\u0026nbsp;(1.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp\u003e2.292\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" valign=\"bottom\"\u003e\n \u003cp\u003eNote. HAMD-17:\u0026nbsp;17-item Hamilton Depression Rating Scale; HAMA-14: 14-item Hamilton Anxiety Rating Scale; AIS: Athens Insomnia Scale; C-SSRS: Columbia-Suicide Severity Rating Scale; SMD: Standard Mean Difference; Bold text is used to indicate statistically significant results.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Suicide attempt during follow-up\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAcross the three follow\u0026ndash;up assessments, the extent of missing data increased over time (See Supplementary Fig. 1). Follow\u0026ndash;up data were complete at the 1-month assessment, whereas 86 cases (15.3%) were missing at 3 months and 162 cases (28.9%) at 6 months, with multiple combined missingness patterns observed across time points. As shown in Table 2. Group differences in suicide attempts emerged only in the first month. Participants with insomnia showed a higher 1-month suicide attempt rate compared with those without insomnia (6.6% vs 1.0%; SMD = 0.30; \u003cem\u003ep\u003c/em\u003e = 0.045). No significant between-group differences were observed during months 1\u0026ndash;3 or months 3\u0026ndash;6 (all \u003cem\u003ep\u003c/em\u003e \u0026ge; 0.05), although numerically higher rates persisted in the insomnia group.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" valign=\"bottom\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;2.\u0026nbsp;Suicide\u0026nbsp;Attempt\u0026nbsp;during\u0026nbsp;Follow-up\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 44px;\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003eNo\u0026nbsp;insomnia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15px;\"\u003e\n \u003cp\u003eInsomnia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003eSMD\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003eSuicide\u0026nbsp;attempt\u0026nbsp;Month\u0026nbsp;0\u0026ndash;1,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.045\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.296\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e1\u0026nbsp;(1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e30\u0026nbsp;(6.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e102\u0026nbsp;(99.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e428\u0026nbsp;(93.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003eSuicide\u0026nbsp;attempt\u0026nbsp;Month\u0026nbsp;1\u0026ndash;3,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.623\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.095\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e3\u0026nbsp;(3.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e20\u0026nbsp;(5.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e88\u0026nbsp;(96.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e364\u0026nbsp;(94.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003eSuicide\u0026nbsp;attempt\u0026nbsp;Month\u0026nbsp;3\u0026ndash;6,\u0026nbsp;n\u0026nbsp;(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.050\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.317\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Yes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e2\u0026nbsp;(2.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e32\u0026nbsp;(10.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" style=\"width: 44px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; No\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 19px;\"\u003e\n \u003cp\u003e79\u0026nbsp;(97.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 15px;\"\u003e\n \u003cp\u003e286\u0026nbsp;(89.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 10px;\"\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\u003e\u003cstrong\u003e3.3 Missing Data Mechanism\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLittle\u0026rsquo;s test indicated that the missing data were not completely at random (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). Logistic regression analyses further showed that missingness at the 1\u0026ndash;3 month and 3\u0026ndash;6 month assessments was significantly associated with age, illness duration, recurrence, and suicide attempt ＞ 3 times (Supplementary Table 1). These findings support the assumption that the missing data mechanism was consistent with missing at random (MAR). Therefore, multiple imputation was applied to handle missing values, and complete-case analyses were conducted as sensitivity checks.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Survival Analysis of Suicide Attempt Risk by Insomnia Status\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKaplan\u0026ndash;Meier curves showed that participants with insomnia experienced a significantly higher risk of suicide attempt over the 6-month follow-up compared with those without insomnia (log-rank \u003cem\u003ep\u003c/em\u003e ＜ 0.001; Fig. 2). Consistent with this pattern, Cox regression indicated that insomnia severity independently predicted increased risk of suicide attempt (HR = 1.07, 95% CI: 1.01\u0026ndash;1.13, \u003cem\u003ep\u003c/em\u003e = 0.038) after adjustment for covariates. Greater depressive severity and prior suicide attempts were also significant predictors, whereas longer illness duration (\u0026gt; 24 months) was associated with reduced risk. Complete case analyses yielded similar results (Table 3).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/95224_ce634422aaf2e7a6/95224_custom_files/img1775442724.png\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.5 Subgroup Analysis of the Association Between Insomnia Severity and Suicide Attempt Risk\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAcross all predefined subgroups, the positive association between AIS scores and suicide attempt risk remained highly consistent (Fig. 3). HR estimates clustered around 1.1 across gender, age, episode status, medication use, illness duration, and suicide history, indicating a stable effect size with no evidence of effect modification (all interaction \u003cem\u003ep\u003c/em\u003e \u0026gt; 0.05). These findings align with the primary Cox model results and suggest that the impact of insomnia severity on suicide risk is broadly comparable across patient subgroups.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Supplementary Analysis: Insomnia Dimensions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn models separating nocturnal symptoms and daytime dysfunction (Supplementary Table 2), neither dimension independently predicted suicide attempts after adjustment (AIS-Nocturnal: HR = 1.06, 95% CI: 0.99\u0026ndash;1.13; \u003cem\u003ep\u003c/em\u003e = 0.11; AIS-Daytime: HR = 1.09, 95% CI: 0.94\u0026ndash;1.25; \u003cem\u003ep\u003c/em\u003e = 0.25). Depressive severity and suicide history remained significant predictors, while longer illness duration was associated with lower risk. These results suggest that no single insomnia dimension accounts for the association observed for overall AIS scores in the primary analysis.\u0026nbsp;\u003c/p\u003e"},{"header":"4 Discussion","content":"\u003cp\u003eWe investigated the prospective association between insomnia severity and subsequent suicide attempts in depressed youth using a 6-month observational longitudinal design in a psychiatric sample. Our results showed that greater baseline insomnia severity was associated with a higher risk of suicide attempts during follow-up, and this association remained after accounting for key clinical factors. The findings were also consistent in sensitivity analyses, supporting the robustness of the main inference.\u003c/p\u003e \u003cp\u003eOur results extend the literature by demonstrating a prospective link between insomnia and suicide attempts in clinically depressed youth, using time-to-event modeling and rigorous adjustment for key clinical confounders, including depression and anxiety severity, after removing overlapping sleep items. Notably, the present prospective results also align with and extend our prior cross-sectional evidence suggesting that sleep disturbance impairment is closely linked to suicidality in depressed youth [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Our findings are consistent with evidence from recent longitudinal research. A 6-month follow-up study of 782 middle school students reported that insomnia was an independent predictor of suicide attempts (OR\u0026thinsp;=\u0026thinsp;6.00) [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Similar patterns have been observed in population-based research[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, it is important to recognize that the above studies were conducted in community-based school samples rather than clinically diagnosed depressed populations, and suicidal outcomes were typically measured using self-report questionnaires or single-item assessments. Such measurement approaches may be vulnerable to recall bias and outcome misclassification, and they do not capture the timing of suicidal behaviors, limiting inference about near-term risk. In contrast, our study focused on treatment-seeking youth with depressive episodes and used repeated assessments over follow-up with time-to-event modeling, thereby providing clinically grounded evidence that insomnia severity confers incremental prognostic value for subsequent suicide attempts beyond overall symptom severity.\u003c/p\u003e \u003cp\u003eIn addition to insomnia, more severe depressive symptoms and a history of suicide attempts were strong predictors of suicide attempts during follow-up in our cohort. This pattern is consistent with evidence from cohort-based meta-analyses in depressive disorders, which identify greater illness severity and prior suicidal behavior as reliable risk markers for later suicide attempts [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. It also fits with prospective findings in clinically depressed adolescents, where baseline suicidal risk indicators predict later attempts [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. In contrast, a longer illness duration (\u0026gt;\u0026thinsp;24 months) was associated with a lower risk in our sample. This finding differs from some previous studies, which reported that longer illness duration was associated with a higher risk of suicide attempts [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. This result should be interpreted with caution. One possible explanation is that suicide attempts may occur more often earlier in the course for some patients, and those who remain in long-term care may receive more monitoring and treatment. Long-term follow-up data in severe depression also suggest that attempt risk can decrease with more years spent depressed, which is broadly consistent with this idea [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Therefore, the direction of this association remains unclear and should be tested again in youth clinical cohorts.\u003c/p\u003e \u003cp\u003eIn supplementary analyses, separating insomnia into nocturnal symptoms and daytime dysfunction did not show statistically significant associations with suicide attempts after covariate adjustment when both components were entered in the same model. This pattern is plausible because insomnia is widely conceptualized as a 24-hour disorder, in which daytime impairment is not merely a consequence but a defining feature of the condition [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The AIS was also developed to capture this combined burden, and its two-factor structure (nocturnal problems and daytime dysfunction) does not imply that these domains operate independently in clinical risk [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In adolescents, prior longitudinal work further suggests that daytime sleepiness can sit on the pathway between insomnia symptoms and subsequent suicidal behavior, supporting an integrated view of nighttime sleep problems and daytime functioning [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Methodologically, nocturnal and daytime subscales are correlated, so including both may reduce the unique information carried by each and weaken statistical signals. Overall, our findings suggest that the AIS total score may better reflect clinically relevant sleep-related risk than either domain alone in this cohort.\u003c/p\u003e \u003cp\u003eThe causal relationship between sleep disturbance and suicidal behavior in depression remains unclear. Prior studies have proposed several hypotheses that may help explain the underlying mechanisms. Behaviourally, insufficient sleep impairs emotion regulation and heightens negative affect in youth [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. Acute sleep loss amplifies emotional reactivity; adolescents show poor inhibition of negative emotions, reduced positive affect [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e], and greater rumination or distress [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. During adolescence, when fronto-limbic circuits are still maturing, chronic sleep loss may undermine prefrontal inhibitory control and decision-making [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. Neuroimaging researches show sleep deprivation weakens prefrontal\u0026ndash;amygdala connectivity and shifts activity toward brainstem and limbic regions [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e], consistent with greater impulsivity and risk-taking in sleep-restricted youth. Biologically, adolescent circadian delays and \u0026ldquo;social jetlag\u0026rdquo; magnify this vulnerability: misalignment of the sleep\u0026ndash;wake cycle produces daytime sleepiness and mood swings that exacerbate emotional lability [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. At the neurochemical level, chronic insomnia may dysregulate serotonin and other modulators of mood and arousal, compromising impulse control and mood stability[\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. In sum, insomnia may amplify suicide risk in depressed teens by degrading affect regulation and executive control via disrupted neural circuits (e.g., prefrontal-amygdala pathways) and desynchronizing circadian-mood biology. These mechanistic insights underscore why treating sleep problems in youth depression is vital for suicide prevention.\u003c/p\u003e \u003cp\u003eThis study has several strengths. By focusing on treatment-seeking adolescents and young adults with depressive disorder, a clinically high-risk population in which sleep disturbances are common, and suicide prevention is a central concern. The prospective cohort design, standardized suicidality assessments, and repeated follow-ups over 6 months allowed us to capture the timing of suicide attempts and model risk over time. This framework supported the use of time-to-event models, which are well-suited to uneven follow-up and censored outcomes. In addition, we reduced potential measurement overlap by excluding sleep-related items from the depression and anxiety scales, which helped isolate the contribution of insomnia severity beyond overall symptom burden. Finally, we addressed incomplete follow-up using multiple imputation and confirmed the main findings with complete-case sensitivity analyses, strengthening confidence in the robustness of the results.\u003c/p\u003e \u003cp\u003eNevertheless, several limitations deserve further discussion. First, the cohort was recruited from a single psychiatric hospital, which may limit generalizability to community samples or to patients in other care settings. Second, insomnia was measured using a self-report scale rather than objective sleep metrics (e.g., actigraphy or polysomnography), so misclassification is possible. Third, follow-up missingness increased over time. Although we used multiple imputation and confirmed the results in complete-case analyses, bias due to unmeasured factors related to attrition may remain. Finally, the follow-up period was limited to 6 months, and we did not model time-varying changes in treatment or symptoms. Longer follow-up and repeated sleep assessments will be important to clarify longer-term risk and potential mechanisms.\u003c/p\u003e"},{"header":"5 Conclusion","content":"\u003cp\u003eIn this 6-month prospective cohort study of youth with depression, greater baseline insomnia severity was associated with a higher risk of subsequent suicide attempts, independent of depressive and anxiety symptom severity and other key clinical factors. These findings suggested that insomnia has meaningful short-term implications for suicidal risk in depressed youth and highlight the potential value of improving sleep assessment and management as part of early risk stratification and suicide prevention in this high-risk population.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank all participants for their time and contribution to this study. All authors also acknowledge the research staff and scientific advisors for their valuable input to the study design.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Sources\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Natural Science Foundation Program of Guangdong (2024A1515013133), the Joint Funding Program by Guangzhou Science and Technology Bureau and Local Universities/Institutions/Enterprises (Project No. 2023A03J0844, 2023A03J0434, 2023A03J0845), and the Guangzhou Key Laboratory of Psychosomatic Medicine (Project No. SL2023A03J00421).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Standards\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors assert that this study was performed in accordance with the institutional research ethics guidelines and the Helsinki Declaration. This study was approved by the Ethics Committee of the Affiliated Brain Hospital of Guangzhou Medical University.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDue to privacy restrictions related to patient data, the datasets \u0026nbsp;generated and/or analyzed during the current study are not \u0026nbsp;publicly available. However, they can be obtained from the \u0026nbsp; corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXuefei Fan: Writing–original draft, Supervision, Methodology, Investigation, Formal analysis. Kunrong Lin: Writing–original draft, Supervision, Methodology, Investigation, Formal analysis. Ziyan Zhou: Writing–original draft, Formal analysis, Data curation. Yarong Ma: Data curation, Formal analysis, Writing. Lin Xiaoming: Resources, Investigation, Formal analysis. Jie Zhang: Funding acquisition, Data curation. Hongbo He: Data curation, Formal analysis, Methodology, Project administration, Funding acquisition, Supervision, Validation, Visualization, and Writing. All the authors commented on previous versions of the manuscript. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eThapar A, Eyre O, Patel V, Brent D. Depression in young people. Lancet. 2022;400:617\u0026ndash;31. https://doi.org/10.1016/S0140-6736(22)01012-1.\u003c/li\u003e\n \u003cli\u003eKang C, Zheng Y, Yang L, Wang X, Zhao N, Guan TF, et al. Prevalence, risk factors and clinical correlates of suicidal ideation in adolescent patients with depression in a large sample of Chinese. 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The effect of sleep deprivation and restriction on mood, emotion, and emotion regulation: three meta-analyses in one. Sleep 2021;44:zsaa289. https://doi.org/10.1093/sleep/zsaa289.\u003c/li\u003e\n \u003cli\u003eUccella S, Cordani R, Salfi F, Gorgoni M, Scarpelli S, Gemignani A, et al. Sleep Deprivation and Insomnia in Adolescence: Implications for Mental Health. Brain Sci. 2023;13(4):569. https://doi.org/10.3390/brainsci13040569.\u003c/li\u003e\n \u003cli\u003ePawley M, Morales-Mu\u0026ntilde;oz I, Bagshaw AP, Tang NKY. Sleep problems, decision-making, and suicide attempts during adolescence: a longitudinal birth cohort study. Sleep Adv 2025;6:zpaf062. https://doi.org/10.1093/sleepadvances/zpaf062.\u003c/li\u003e\n \u003cli\u003eJamieson D, Broadhouse KM, Lagopoulos J, Hermens DF. Investigating the links between adolescent sleep deprivation, fronto-limbic connectivity and the Onset of Mental Disorders: a review of the literature. Sleep Med 2020;66:61\u0026ndash;7. https://doi.org/10.1016/j.sleep.2019.08.013.\u003c/li\u003e\n \u003cli\u003eRolling J, Ligier F, Rabot J, Bourgin P, Reynaud E, Schroder CM. Sleep and circadian rhythms in adolescents with attempted suicide. Sci Rep 2024;14:8354. https://doi.org/10.1038/s41598-024-57921-2.\u003c/li\u003e\n \u003cli\u003eBlake MJ, Trinder JA, Allen NB. Mechanisms underlying the association between insomnia, anxiety, and depression in adolescence: Implications for behavioral sleep interventions. Clin Psychol Rev 2018;63:25\u0026ndash;40. https://doi.org/10.1016/j.cpr.2018.05.006.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"child-and-adolescent-psychiatry-and-mental-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"caph","sideBox":"Learn more about [Child and Adolescent Psychiatry and Mental Health](http://capmh.biomedcentral.com)","snPcode":"13034","submissionUrl":"https://submission.nature.com/new-submission/13034/3","title":"Child and Adolescent Psychiatry and Mental Health","twitterHandle":"@IACAPAP","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Insomnia, Suicide attempts, Youth, Depression, Prospective cohort study","lastPublishedDoi":"10.21203/rs.3.rs-9144236/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9144236/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEvidence linking insomnia to suicidal risk in depressed youth is largely cross-sectional, limiting inference about temporal direction. We examined whether baseline insomnia severity predicts subsequent suicide attempts in this population.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted a 6-month prospective cohort study of depressed youth recruited from a psychiatric hospital from January to June 2022. We examined the association between baseline insomnia severity and time to first suicide attempt using Kaplan–Meier curves and multivariable Cox proportional hazards models.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 561 participants were included in the final analysis (428 female participants [76.3%]). At baseline, 458 participants met the criteria for insomnia (Athens Insomnia Scale [AIS] ³6; 81.6%). In multivariable Cox models, insomnia severity was independently associated with a higher hazard of suicide attempts (HR = 1.07, 95% CI = 1.01–1.13, \u003cem\u003ep\u003c/em\u003e = 0.038). Kaplan–Meier curves also showed a significant difference in time to first suicide attempt between the insomnia and non-insomnia groups (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). In addition, greater depressive severity (HR = 1.11, 95% CI = 1.04–1.18, \u003cem\u003ep\u003c/em\u003e = 0.002), and a lifetime history of suicidality (HR = 2.14, 95%CI = 1.31–3.48, \u003cem\u003ep\u003c/em\u003e = 0.004) predicted follow-up attempts, whereas a longer illness duration (\u0026gt;24 months) was associated with a lower hazard (HR = 0.34, 95% CI = 0.17–0.69, \u003cem\u003ep\u003c/em\u003e = 0.005).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study confirms that insomnia is an independent predictor of suicide attempts in youth with depression. The findings support early identification and intervention for suicidal risk in this vulnerable population.​\u003c/p\u003e","manuscriptTitle":"Insomnia Severity Predicts Suicide Attempts in Youth with depression: A 6-Month Prospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-06 05:43:38","doi":"10.21203/rs.3.rs-9144236/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-29T16:25:44+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-27T13:02:11+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-26T14:51:54+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-20T13:21:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"103419730679089680628771929791512518836","date":"2026-04-13T11:33:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"282416428358212578681688642116165999621","date":"2026-04-02T12:46:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"306067819799794436338856187224237539633","date":"2026-04-01T02:17:15+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-31T19:34:40+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-24T09:30:52+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-21T06:47:41+00:00","index":"","fulltext":""},{"type":"submitted","content":"Child and Adolescent Psychiatry and Mental Health","date":"2026-03-17T05:18:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"child-and-adolescent-psychiatry-and-mental-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"caph","sideBox":"Learn more about [Child and Adolescent Psychiatry and Mental Health](http://capmh.biomedcentral.com)","snPcode":"13034","submissionUrl":"https://submission.nature.com/new-submission/13034/3","title":"Child and Adolescent Psychiatry and Mental Health","twitterHandle":"@IACAPAP","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3dac824f-6380-48cd-9dbc-1b9ba96eaca0","owner":[],"postedDate":"April 6th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-04-29T16:25:44+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-17T17:23:36+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-06 05:43:38","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9144236","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9144236","identity":"rs-9144236","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}