Accelerated Magnetic Seizure Therapy for Non‐Suicidal Self‐Injury in Adolescents With Bipolar Depression

Background Adolescents with bipolar depression are typically characterized by a high prevalence of non‐suicidal self‐injury (NSSI), yet effective therapies remain limited. Accelerated magnetic seizure therapy (aMST) has emerged as a promising neuromodulation technique with potential cognitive advantages. However, evidence regarding its clinical efficacy, cognitive impact, neurostructural and functional alterations in adolescents remains unclear. Methods Adolescents diagnosed with bipolar depression and comorbid NSSI received once‐daily accelerated MST sessions. Clinical symptoms, including depression, anxiety, impulsivity, and emotion regulation, were assessed before and after aMST. Cognitive function was evaluated using the MATRICS Consensus Cognitive Battery (MCCB) and autobiographical memory test (AMT). Structural MRI and diffusion tensor imaging (DTI) were collected to compare the potential neurostructural and functional change induced by aMST. Results Thirty‐two adolescents completed the whole aMST protocol. Following aMST, significant reductions were observed in depressive and anxiety symptoms. Improvements were also found in impulsivity and emotion regulation. Assessment of cognitive function revealed no global impairment. Significant enhancements were found in processing speed, working memory, and visual learning, while verbal learning remained largely unchanged. Autobiographical memory (AM) performance was generally preserved, with a reduction in overgeneral autobiographical memory (OGM) for positive cues. Neuroimaging analyses demonstrated no significant changes in total hippocampal volume or hippocampal subfield volumes. DTI analyses suggested increased fractional anisotropy (FA) in the right uncinate fasciculus and increased mean diffusivity (MD) in the left superior longitudinal fasciculus following aMST. Conclusions These findings provide preliminary evidence that aMST is associated with clinical improvement and favorable cognitive function in adolescents with comorbid bipolar depression and NSSI. The stably maintained volumes of hippocampal subfield, alongside selective white matter microstructural alterations, suggest that aMST may exert targeted neuroplastic effects while preserving structures which are critical for cognition. Trial Registration Chinese Clinical Trial Registry: ChiCTR2500114164