Abstract
BACKGROUND: Childhood trauma exacerbates bipolar disorder in adolescents, particularly intensifying depressive symptoms. While the potential mechanisms are unclear, sleep disturbances might mediate the link between childhood trauma and depression. This study investigated if sleep problems mediate the relationship between childhood trauma and depression severity in adolescents with bipolar disorder. METHODS: 426 adolescents with bipolar I or II disorder were recruited from Renmin Hospital of Wuhan University in 2024. They completed questionnaires on the Childhood Trauma Questionnaire, the Pittsburgh Sleep Quality Index, and the Patient Health Questionnaire-9. Data analysis included Pearson correlations and a mediation analysis using the PROCESS macro to examine the proposed indirect effect. RESULTS: Correlation analyses revealed significant positive associations between childhood trauma, sleep disturbance, and depressive symptoms (all p < 0.001). Controlled the variables of age, gender, and diagnosis classification, the mediation analysis confirmed that sleep disturbance served as a significant partial mediator in the relationship between childhood trauma and depressive symptoms. The indirect effect was significant (B = 0.071, 95% CI =[0.0495, 0.0944]), accounting for 38.59% of the total effect. CONCLUSION: Our findings demonstrate that sleep disturbance represented a critical mediating mechanism in the association between childhood trauma and depressive symptoms among adolescents with bipolar disorder. These results underscore the importance of systematically assessing and addressing sleep disturbances in both clinical care and therapeutic management, particularly for at-risk individuals with a history of early-life adversity. CLINICAL TRIAL NUMBER: Not applicable.