Abstract
BACKGROUND: The adolescent depression associated with childhood trauma has been confirmed, but the underlying mechanisms remain unclear. This study aims to explore the chain-mediated role of borderline personality traits and self-control in the relationship between childhood trauma and adolescent depression. METHODS: A cross-sectional study was conducted on 2,664 students from a senior high school through online questionnaires from October to December 2022 in Henan, China. Childhood Trauma Questionnaire-Short Form, Borderline Personality Dimension of Personality Diagnostic Questionnaire-4, Self-Control Scale, and Children's Depression Inventory were used to measure childhood trauma, borderline personality traits, and self-control. RESULTS: The prevalence of depression in adolescents was 21.17%, while the prevalence of borderline personality was 12.00%. childhood trauma (r = 0.50, p < 0.001) and borderline personality traits (r = 0.60, p < 0.001) were positively correlated with adolescent depressive symptoms, while self-control was negatively correlated with depressive symptoms (r = - 0.50, p < 0.001). Borderline personality traits and Self-control both play a mediating role in childhood trauma and depressive symptoms, and the mediating effect values are 0.116 (95%CI = [0.098, 0.137]), and 0.022 (95%CI = [0.012, 0.032]) respectively. The chain mediating effect of borderline personality traits and self-control on the relationship between childhood trauma and depressive symptoms was significant (effect value: 0.034, 95%CI = [0.028, 0.042]). CONCLUSIONS: Childhood trauma can predict depressive symptoms in adolescents due to the formation of borderline personality traits and the reduction of self-control. These findings are important for understanding the formation of personality traits, self-control abilities and coping strategies shaped by traumatic experiences in adolescents.