Deep Brain Stimulation for Refractory OCD and Depression: From Neurocircuitry to Personalised Neuromodulation

ObjectiveDeep brain stimulation (DBS) has emerged as a promising intervention for severe, treatment-resistant psychiatric disorders such as obsessive-compulsive disorder (OCD) and treatment-resistant depression (TRD), where conventional therapies often fail. Despite overlapping neurocircuitry, the clinical trajectories and translational challenges of these conditions differ substantially. This review examines the current evidence and advancements in DBS for severe, treatment-resistant psychiatric disorders.MethodsA literature search was conducted to identify relevant studies on DBS for OCD and TRD. The search was performed in PubMed and Google Scholar, covering publications from 2020 to 2025. Older studies were included if deemed essential references. Keywords and Boolean combinations such as "DBS," "deep brain stimulation," "OCD," "TRD," "treatment-resistant depression," and "psychiatric neuromodulation" were used to refine the search and enhance specificity.ResultsClinical findings demonstrate sustained long-term benefits of DBS in OCD, although recent sham-controlled trials report smaller effect sizes than earlier open-label studies. In TRD, outcomes remain inconsistent, with open-label trials showing high response rates but larger randomised trials failing to significantly outperform sham stimulation. Emerging innovations include connectomic-guided targeting, AI-assisted predictive models, and closed-loop DBS systems driven by neural biomarkers.ConclusionDBS remains a promising therapy for refractory OCD and TRD. Future progress depends on addressing methodological, ethical, and translational challenges while advancing personalised, data-driven neuromodulation strategies.