To explore the chain mediation role of social withdrawal and self-esteem in the relationship between childhood trauma and depression among junior high school students, to inform youth mental health interventions.

From June to August 2025, a stratified sampling survey was conducted among 2 630 students from five junior high schools in Tai’an, Shandong. Core variables were assessed using the social withdrawal dimension of the Youth Self-Report, the Self-Esteem Scale, the Childhood Trauma Questionnaire, and the Depression Screening Questionnaire. Pearson correlation tested associations among variables. Multiple linear regression tested effects on depression. Mediation models with bootstrapping tested the chain mediation of social withdrawal and self-esteem.

All trauma dimensions were positively related to social withdrawal and depression, and negatively to self-esteem. Social withdrawal was negatively related to self-esteem and positively to depression. Self-esteem was negatively related to depression. Further analysis showed that all trauma dimensions directly predicted higher depression (β=0.335, 0.113, 0.237, 0.152, 0.175; all P<0.001), and indirectly predicted higher depression via social withdrawal (β=0.196, 0.110, 0.172, 0.138, 0.176; Boot 95% CI excluded 0) and via the chain “trauma →social withdrawal → low self-esteem → depression” (β=0.020, 0.010, 0.025, 0.014, 0.026; Boot 95% CI excluded 0). Self-esteem also significantly mediated the associations between emotional abuse, emotional neglect, physical neglect, and depression (β=0.021, 0.037, 0.025; Boot 95% CI excluded 0).

Social withdrawal and low self-esteem play a chain mediation role in the relationship between childhood trauma and depression among junior high school students. Timely interrupting risk factors and developing protective factors are crucial for improving the mental health of adolescents.