Abstract
PURPOSE: Adolescents with depressive symptoms are particularly vulnerable and at higher risk for developing co-occurring mental health issues, such as non-suicidal self-injury (NSSI). This study focused on adolescents exhibiting persistent depressive symptoms across three time points and investigated how childhood maltreatment influences NSSI and its changes over time, along with the underlying mechanisms. METHODS: From a larger sample of 3981 students, 317 adolescents with persistent depressive symptoms (M (age) = 13.20, SD = 0.82) were identified, and a control group of 317 non-depressed adolescents was selected via propensity score matching. Latent change score (LCS) modeling and longitudinal mediation models were employed to examine the mechanisms linking childhood maltreatment to NSSI and its changes. RESULTS: The univariate LCS model revealed an increasing trend in NSSI behaviors among adolescents with depressive symptoms over the measurement period. T1 childhood maltreatment indirectly influenced T2 NSSI through T2 self-esteem and T2 emotional reactivity. Additionally, T1 childhood maltreatment significantly predicted changes in NSSI through T2 emotional reactivity. CONCLUSIONS: This study underscores the importance of addressing NSSI in adolescents with depressive symptoms and highlights the necessity of screening for childhood maltreatment histories in this population. The findings provide a foundation for future prevention and intervention efforts, suggesting that enhancing self-esteem and reducing emotional reactivity could mitigate the impact of childhood maltreatment on NSSI in depressed adolescents.