Abstract
BACKGROUND: Non-suicidal self-injury (NSSI) has high prevalence among adolescents with mood disorders and is accompanied by cognitive impairments. Most existing studies have examined their impairments on single cognitive domains. It remains unclear which cognitive deficits are associated with adolescent NSSI and its functions and addictive features, from a multidimensional perspective. METHODS: A total of 161 adolescents diagnosed with first-episode major depressive disorder (MDD) and 137 healthy controls were recruited between June 2020 and December 2024. Participants were divided into three groups: adolescents with MDD and NSSI (MDD + NSSI, n = 84, age = 15.47 ± 1.59), those with MDD and without NSSI (MDD-NSSI, n = 77, age = 16.11 ± 2.16), and healthy controls (HCs, n = 137, age = 15.92 ± 3.13). NSSI behavior and its four common functions (internal emotion regulation, external emotion regulation, social influence, and sensation seeking) as well as the addiction feature, were assessed using the Ottawa Self-injury Inventory. Cognitive domains such as emotion recognition, cognitive control, working memory, and reward processing were assessed using an in-house Cognitive Assessment Battery. Data were analyzed via ANOVA, logistic regression, and multiple linear regression. RESULTS: Both the MDD + NSSI and MDD-NSSI groups showed significantly greater cognitive dysfunctions compared to the HCs. Logistic regression models indicated that cognitive domains such as memory, cognitive control, reward processing, delay discounting, and time perception were significantly associated with the presence of NSSI among adolescents with MDD. Multiple linear regression analyses further revealed that emotion recognition, working memory, cognitive control, and reward processing were significantly related to NSSI functions and the addictive features. CONCLUSIONS: Our results showed that NSSI behaviors, its functions, and addictive features are all associated with multidimensional cognitive dysfunctions. These findings highlight the clinical relevance of implementing thorough, multidomain cognitive evaluations in adolescents with NSSI. CLINICAL TRIAL NUMBER: Not applicable.