Effect of Adverse Childhood Experiences on Nonsuicidal Self-Injury in Adolescents With Mood Disorders

Background: Nonsuicidal self-injury (NSSI) is a severe global health concern, particularly among adolescents, and is closely associated with adverse childhood experiences (ACEs). However, the underlying mechanisms by which ACEs are associated with NSSI remain largely unknown, although peer attachment and alexithymia have been identified as potentially relevant to this relationship. This observational study aimed to test a chain mediation model examining the indirect associations among ACEs, peer attachment, alexithymia, and NSSI in adolescents with mood disorders. Methods: A total of 363 adolescents with mood disorders were recruited from the outpatient clinical psychology department of a general hospital. Clinical interview tools and self-report questionnaires were used to evaluate patients’ history of NSSI, ACEs, peer attachment, and alexithymia. Comparisons were made between groups of patients who did and did not meet the criteria for NSSI diagnosis, and peer attachment and alexithymia were evaluated for potential mediating effects. Results: In total, 203 (55.9%) patients were included in the NSSI group. In the chain mediation model, ACEs were directly associated with NSSI, with a significant effect size of 0.246 (95% confidence interval [CI]: 0.088, 0.404), accounting for 64.2% of the total effect. Peer attachment and alexithymia had a total indirect effect of 0.137 (95% CI: 0.079, 0.221), accounting for 35.8% of the total effect. Conclusions: In addition to reaffirming the direct association between ACEs and NSSI, this study provides novel insight into a chain of indirect associations linking peer attachment and alexithymia to the ACE-NSSI relationship.