Glucose Consumption During Deep Brain Stimulation With Functional [18F]FDG-Brain-PET in Obsessive-Compulsive Disorder

This study is using a brain imaging technique (FDG-PET scan) to measure glucose (sugar) use in specific brain regions during deep brain stimulation (DBS) therapy in people with severe, treatment-resistant OCD. The goal is to understand exactly how DBS changes brain activity in OCD. **You may be eligible if...** - You have severe OCD (score of 25 or higher on the Yale-Brown OCD scale) - You have tried and failed at least two medications (serotonin reuptake inhibitors) at adequate doses and duration - You have also tried other medication augmentation strategies and cognitive-behavioral therapy - You can provide written informed consent **You may NOT be eligible if...** - You have a history of psychosis - You have significant other neurological or psychiatric conditions - You are pregnant - You cannot tolerate the imaging or surgical procedures required Talk to your doctor to see if this trial is right for you.