Childhood trauma profiles and addictive features of adolescent non-suicidal self-injury: The roles of rumination and age of onset.

Non-suicidal self-injury (NSSI) is a major public health concern among adolescents, with evidence suggesting that repetitive NSSI may share addiction-like characteristics. This study examined how childhood trauma profiles are associated with addictive features of NSSI, focusing on rumination as mediator and age at onset as moderator. A latent class analysis of 1506 adolescents identified four trauma profiles: low trauma, high neglect trauma, high emotional trauma, and complex trauma. Adolescents in the high emotional and complex trauma groups showed higher addictive features of NSSI. Rumination partially mediated this relationship. Age of onset moderated the association between complex trauma and addictive features of NSSI, with earlier onset linked to stronger addictive tendencies. Johnson-Neyman analysis showed this association was significant when onset age was approximately 15.81 years or younger. These findings highlight trauma-related pathways underlying addictive features of NSSI and underscore the importance of early interventions targeting trauma and rumination in high-risk youth.