Differential pathways from childhood maltreatment types to non-suicidal self-injury in adolescents with depressive disorders: a serial mediation model

Abstract

Non-suicidal self-injury (NSSI) is prevalent among adolescents with depressive disorders, with childhood maltreatment (CM) as a key risk factor. However, how distinct CM types differentially influence NSSI risk in this population remains unclear. Moreover, emotion dysregulation and depressive symptoms have rarely been tested together as serial mediators within a single model. This study examined the serial mediating effects of emotion dysregulation and depressive symptoms linking five CM types to NSSI and compared their distinct pathways. A total of 426 adolescents with depressive disorders (218 males, 208 females; mean age = 14.74 years, SD = 1.93) were enrolled. CM, NSSI, emotion dysregulation, and depressive symptoms were assessed using the Childhood Trauma Questionnaire-Short Form, Functional Assessment of Self-Mutilation, the Difficulties in Emotion Regulation Scale-16, and the depression subscale of the Symptom Checklist-90, respectively. Serial mediation was assessed via structural equation modeling using the MLR estimator, with indirect effects tested via robust 95% confidence intervals (delta method). Emotional abuse (β = 0.157) exerted direct effects on NSSI, as did physical abuse (β = 0.179), while neglect types did not. Indirect pathways varied by maltreatment type: emotional abuse operated through emotion dysregulation alone (β = 0.087), depressive symptoms alone (β = 0.026), and the serial pathway (β = 0.036). Both emotional and physical neglect demonstrated indirect effects through emotion dysregulation (β = 0.097 and 0.091, respectively) and through the serial pathway (β = 0.041 and 0.038, respectively), but physical neglect did not operate through depressive symptoms alone. Formal contrasts showed no differences in total indirect effects among emotional abuse, emotional neglect, and physical neglect, whereas physical abuse and sexual abuse had significantly weaker total indirect effects. Sexual abuse showed no significant effects. Five CM types influence NSSI risk through differential pathways in adolescents with depressive disorders. Emotion dysregulation served as a shared mediating mechanism for emotional abuse and neglect, but not for physical abuse or sexual abuse. Emotion regulation training may be beneficial for reducing NSSI among depressed adolescents exposed to emotional abuse or neglect.