Deep Brain Stimulation for Refractory Obsessive-Compulsive Disorder

The goal of this clinical trial is to learn if deep brain stimulation (DBS) works to treat refractory obsessive-compulsive disorder (OCD). The main questions it aims to answer are: * Assess the effects of the anteromedial sub-thalamic nucleus (amSTN)stimulation on obsessive/compulsive symptoms. * Map the amSTN using neuronal responses \[single unit and local field potentials (LFP) recordings\] at rest and under high frequency stimulation during surgery. * Record chronic brain activity with the implanted pulse generator and look for neuronal signatures correlated with symptom severity. Researchers will compare active deep brain stimulation to a placebo (sham stimulation) to see if DBS works to treat refractory OCD. Participants will: * Undergo surgery for the implantation of a deep brain stimulation device * Follow-up visits every three weeks with study staff * 6 month follow-up for the next 2-3 years after first year of study participation is complete