Impulsivity in Adolescents with MDD and Non-Suicidal Self-Injury: A Multimodal Assessment Using Psychometric, Behavioral, and Neurophysiological Measures

Objective: This study aims to explore the impulsivity traits across various dimensions and their neuro-electrophysiological features in adolescent depressed patients withnon-suicidal self-injury (NSSI) via scale assessments, behavioral tasks, and event-related potentials (ERPs). Methods: A case-control study was conducted, enrolling depressed adolescent patients with NSSI (NSSI group), depressed adolescent patients without NSSI (non-NSSI group), and healthy controls. The Barratt Impulsivity Scale (BIS-11), go/no-go task, and ERPs were utilized to assess different dimensions of impulsivity. Results: Both the NSSI group and the non-NSSI group demonstratedsignificantly higher total scores and subscale scores on the BIS-11 compared to the healthy control scores than the HC group in the total score and subscale scores of the BIS-11, especially in the motor impulsivity subscale in the motorimpulsivity subscale ( p < 0.05). The NSSI group had lower accuracy in the go task than the non-NSSI and HC groups, with a statistically significant difference ( p =0.009); notably, the significant difference was more pronounced between the NSSI and HC groups( p =0.008). No significant differences were found in the latency and amplitude of N2 and P3 waves among the three groups ( p > 0.05). The severity of NSSI over the past 1 month, 6 months, and 12 months was positively correlated with the motor impulsivity subscale and the total score of the BIS (r=0.198 to 0.417, p < 0.001). In contrast, it was negatively correlated with the accuracy of the go task (r=-0.248 to -0.193, p < 0.001). Conclusion: Adolescent depressed patients with NSSI showed increased self-reported and behaviorally measured motor impulsivity, and these changes were strongly associated with the severity of NSSI.