Brain Recordings in Patients Undergoing Deep Brain Stimulation (DBS) for Severe Obsessive-Compulsive Disorder (OCD)

Obsessive-compulsive disorder effects approximately 2-3% of the population. The only established first-line treatments for OCD are cognitive-behavioral therapy (CBT) with exposure/response prevention and serotonin reuptake inhibitor medications (SRIs). Approximately 30-40% of patients fail to respond to either modality and few patients experience complete symptom resolution. Up to 25% of patients have difficulty tolerating CBT, and the risk of relapse after therapies remains significant. Symptoms of OCD include unwanted, distressing thoughts and rituals such as excessive washing of hands or other body parts, rechecking things such as locks or switches because of obsessional doubt, and avoidance of anxiety-provoking situations. In some cases, compulsions can consume several hours per day and in the most extreme cases can involve most of the patient's waking hours (e.g. washing hands hundreds of times per day, 18-hour showers). Medical complications may result from repeated washing or other repetitive behaviors. Significant social and occupational impairment can result from this disorder and some patients are housebound or even bed-ridden. Effective evidence-based treatments include behavior therapy and certain medications. Despite these therapies, a significant number of patients are treatment resistant and suffer persistent, debilitating symptoms. In severe cases, neurosurgical intervention is sometimes performed to alleviate symptoms. A common surgical option is deep brain stimulation (DBS), a procedure that involves placing two electrodes in a specific region in the brain and connecting them to a pacemaker-like device implanted under the skin in the upper chest. The clinician adjusts the stimulation parameters on the device to find the settings that best relieve symptoms. One of the challenges of treating a psychiatric disorder is the absence of reliable and valid biomarkers for diagnosing and objectively monitoring treatment outcomes. There is also problem of h