Biological rhythm and depression severity mediate the relationship between adverse childhood experiences and non-suicidal self-injury among adolescents with depressive disorder

Non-suicidal self-injury (NSSI) is prevalent in adolescents with first-episode major depressive disorder (MDD). Adverse childhood experiences (ACEs) and biological rhythm disorder (BRD) have been recognized as risk factors for NSSI in patients with MDD. However, the mechanisms that lead to NSSI remain unclear. A total of 270 adolescents with first-episode depression were consecutively recruited from the outpatient department of a tertiary hospital in China to measure the symptoms of ACEs, NSSI, BRD, and severity of depression using the Adverse Childhood Experience Questionnaire, Adolescent Non-Suicidal Self-Injury Assessment Questionnaire, Self-Rating of Biological Rhythm Disorder for Adolescents, and Hamilton Depression Rating Scale. Our findings indicate that ACEs are associated with an increased risk of NSSI. A sequential mediation model further revealed that BRD and depression severity mediated the relationship between ACEs and NSSI. This study contributes to understanding the pathophysiology of NSSI. In addition, improving biological rhythms in adolescents with MDD who experience ACEs could help decrease the severity of depression and prevent them from engaging in NSSI behaviors.