Progress and challenges in deep brain stimulation for obsessive-compulsive disorder.

This narrative review summarizes the recent literature on deep brain stimulation for treatment resistant obsessive-compulsive disorder highlighting both progress and challenges of this novel treatment. Common targets of psychiatric deep brain stimulation involve both white matter trajectories (anterior limb of the internal capsule, inferior thalamic peduncle, and medial forebrain bundle) and grey matter subcortical nuclei (nucleus accumbens, nucleus subthalamicus, and bed nucleus of the stria terminalis) each of which have been reported with a relevant beneficial effect on obsessive-compulsive symptoms. The mechanisms of action are only partially understood but increasing evidence points towards network effects involving the prefrontal cortex, the striatum and possibly anxiety-related anatomical structures. Deep brain stimulation is a promising therapeutical technique for otherwise treatment refractory patients, but many major issues are unresolved and thorough investigations are needed. Relevant topics for future investigations include treatment predictors and therapeutical augmentation. An international registry of patients treated with deep brain stimulation could improve our understanding of adverse events and target specific effects. In order to step forward, researchers must face inconvenient questions and outperform the status quo of clinical research in this field.