From Early Trauma to Self-Harm: A Sequential Mediation Model of Self-Efficacy, Psychological Resilience, and Depression in Adolescents

Objective Examining the mechanisms through which childhood trauma influences non-suicidal self-injury (NSSI) among adolescents suffering depressive disorders via self-efficacy, psychological resilience, and depression, thereby providing theoretical support for adolescent mental health interventions. Methods The Children's Depression Inventory (CDI), the Childhood Trauma Questionnaire (CTQ), the Connor-Davidson Resilience Scale (CD-RISC), the Adolescent Non-Suicidal Self-Injury Assessment Questionnaire (ANSAQ), and the General Self-Efficacy Scale (GSES) were used to assess 201 adolescents aged 10–19 years with depressive disorders who attended a psychiatric hospital in Zhejiang Province from September 2024 to March 2025. After excluding outliers (calculated using Mahalanobis distance), data analysis was conducted on 200 patients. Results Childhood trauma was positively associated with NSSI and depression, and inversely linked to adolescents' self-efficacy and psychological resilience. NSSI was positively associated with depression. Childhood trauma exerted a chained mediating effect on NSSI via self-efficacy, psychological resilience, and depression. Conclusion Childhood trauma exerted a serial mediating effect on NSSI through self-efficacy, psychological resilience, and depression, implicating these three factors as key conduits in the childhood trauma to NSSI pathway. These findings highlight the key role of psychosocial mechanisms in NSSI etiology and suggest that interventions for adolescents with childhood trauma should prioritize enhancing self-efficacy and resilience while concurrently managing depressive symptoms, thereby disrupting the cascading trajectory from trauma to self-injury.