In clinical samples of adolescents with depression, the underlying causes of non-suicidal self-injury (NSSI) across different developmental stages of adolescence are not well understood. This study explored stage-specific differences by comparing psychosocial factors and investigating possible causal links between NSSI and depressive symptoms in middle adolescence (13–15 years) versus late adolescence (16–18 years). A total of 1,530 Chinese adolescents with a diagnosis of depression were enrolled in the study. The presence of non-suicidal self-injury (NSSI) in the past year was assessed using the Functional Assessment of Self-Mutilation (FASM). Psychosocial factors were measured with the Patient Health Questionnaire (PHQ-9), Toronto Alexithymia Scale (TAS), Childhood Trauma Questionnaire (CTQ), Multidimensional Peer Victimization Scale (MPVS), and Multidimensional Scale of Perceived Social Support (MSPSS). To examine stage-specific differences in network centrality and causal pathways, partial correlation networks and Bayesian network analysis were applied. Depressive symptoms demonstrated a probabilistic directional association with NSSI during middle adolescence, whereas peer victimization emerged as a primary probabilistic link to NSSI in late adolescence. Gender demonstrated a stable direct edge to NSSI, with no consistent indirect paths through other measured variables. Within the directed acyclic graph, childhood trauma emerged as a putative upstream factor, exhibiting strong connections to peer victimization and social support. These findings indicate that factors including depressive symptoms, gender, and peer victimization exerted distinct effects on NSSI across developmental stages. Future research should prioritize the specific influence of adolescence as a dynamic developmental period on the etiology and maintenance of NSSI.
Sun et al. (Thu,) studied this question.