BackgroundAdolescents with nonsuicidal self-injury (NSSI) often show deficits in negative emotion regulation. Within the dual-process framework of implicit and explicit emotion regulation, these deficits may reflect an automatic bias toward negative information and insufficient later-stage controlled regulation. Whether routine clinical intervention modifies both early automatic detection and later controlled evaluation of negative emotional information remains unclear.MethodsIn a longitudinal sample of 32 adolescents with NSSI, we examined changes in mismatch negativity (MMN) and P3 components elicited during an emotional oddball task before and after a 12-week clinical intervention. At baseline and Week 12, participants completed clinical assessments and a two-choice visual emotional oddball task containing neutral standards and negative, positive, and neutral deviants while EEG was recorded. MMN (Fz, 240–300 ms) and P3 (Pz, 450–650 ms) amplitudes were derived from deviant-minus-standard difference waves, indexing pre-attentive deviance detection and controlled evaluation, respectively.ResultsThe intervention selectively modulated neurocognitive processing of negative deviants. Self-injury ideation days (p = .036) and NSSI episode frequency (p = .007) both significantly decreased. MMN absolute amplitude to negative stimuli decreased significantly (p = .047), suggesting attenuated automatic salience detection, whereas P3 amplitude to negative stimuli increased significantly (p = .027), indicating enhanced controlled evaluation. Responses to positive and neutral conditions and behavioural performance remained stable. No baseline ERP–clinical correlations emerged; post-intervention, NSSI ideation days correlated with positive P3 (r = 0.380, p = .032), and episode frequency with neutral P3 (r = 0.461, p = .008).ConclusionsA 12-week intervention may attenuate automatic negative bias while enhancing controlled evaluative processing in adolescents with NSSI, consistent with the implicit–explicit framework. MMN and P3 may serve as candidate biomarkers and temporally sensitive tools for tracking intervention response when behavioural performance is stable.
Radically different