NSSI behavior is highly prevalent among adolescents, and its mechanisms are closely associated with attentional bias toward self-injury-related information and impulsivity, both of which may be related to reduced dlPFC activation levels. Introducing taVNS as a priming stimulus to pre-regulate brain state and optimize subsequent tACS treatment response provides a novel approach to addressing inconsistent intervention effects. Simultaneously, this facilitates a shift in the brain from passive stimulus reception to active state regulation, offering important theoretical foundations for developing more precise and efficient cross-modal neuromodulation therapies.This study aims to systematically validate the efficacy of a combined protocol using taVNS as a priming modality followed by tACS over the left dlPFC through a randomized controlled trial (RCT). The investigators hypothesize that:
① Compared to tACS intervention alone, this combined approach will not only demonstrate non-inferiority in overall therapeutic efficacy but, more importantly, significantly reduce inter-individual variability in treatment response to tACS. This would mitigate the issue of high clinical response heterogeneity and enhance the stability and predictability of treatment outcomes.
② Early behavioral biomarkers of intervention response are anticipated: Immediate improvements in attentional bias following a single combined intervention session will significantly predict reductions in the frequency and intensity of Non-Suicidal Self-Injury (NSSI) after a full course (14 sessions) of treatment. This suggests that early positive changes in cognitive function could serve as valid indicators predicting long-term clinical efficacy, offering a critical time window for implementing individualized treatment adjustments.
③ The study will elucidate the effects of the taVNS-primed combined tACS treatment on neuroimaging mechanisms in adolescents with NSSI.