Update on deep brain stimulation for neuropsychiatric disorders.

Deep brain stimulation (DBS) has proven a powerful treatment for medication refractory movement disorders. Success in this group of patients has allowed preliminary studies of DBS to proceed in severe and medication resistant cases of depression, obsessive-compulsive disorder (OCD) and Tourette's syndrome (TS). Pathophysiological and imaging studies along with attempts at lesioning the basal ganglia, have offered clues as to nodes in the circuitry that may be amenable to neuromodulation. DBS in neuropsychiatric illness has offered hope, but at this time rigorous screening by interdisciplinary and ethical teams should be employed when establishing treatment candidacy. A cautious approach to these disorders utilizing institutional review board approved research protocols will hopefully shed light onto patient selection and brain target(s) for each disorder. We need to keep an open mind as we move forward and especially that rational therapy may need to be patient and symptom specific. This review will summarize each disorder (depression, OCD and TS), review pathophysiology (both known and speculated), and update the current observations on DBS in each neuropsychiatric condition.