Longitudinal outcomes and clinical predictors of VC/VS deep brain stimulation in severe obsessive–compulsive disorder: A case series

Deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) is an established treatment for severe, treatment-refractory obsessive–compulsive disorder (OCD). While efficacy is well documented, less is known about temporal response patterns, such as effects at the first follow-up after implantation, longitudinal symptom trajectories, and clinical predictors of individual responses in this cohort. Twenty patients who underwent VC/VS-DBS, were repeatedly assessed using the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS) from baseline to long-term follow-ups (mean duration 22 months, range 6–99). Effects at the first follow-up were assessed by comparing baseline and first post-implantation scores. Longitudinal changes were analysed using linear mixed-effects models, including demographic, illness-related, affective, comorbidity, and symptom dimension variables as exploratory predictors in this modest sample. DBS produced significant symptom reduction at the first follow-up and sustained improvement over follow-ups, although trajectories varied across individuals. Twelve patients were full responders (≥35% reduction), two were partial responders (25–34%), and six were non-responders (<25% reduction). Age of OCD onset interacted with time, with later-onset patients showing slower improvement over time. Age at implantation also interacted with time, indicating age-related differences in symptom reduction pace. Other clinical variables were not significantly linked to symptom trajectories. Overall, VC/VS-DBS provides robust and lasting symptom relief in severe OCD, while most clinical characteristics have limited predictive value for individual treatment responses. These findings highlight the utility of longitudinal modelling, and the need to explore neurobiological markers to better understand variability in DBS outcomes.