• OCD severity (Yale-Brown Obsessive-Compulsive Scale) [ Time Frame: Measured at baseline, monthly for 4 months, then every 3 months for 9 months, and then every 6 months for up to 4 years ] [ Designated as safety issue: No ]
  

• Quality of life (Quality of Life Enjoyment and Satisfaction Questionnaire), depression severity (Montgomery-Asberg Depression Rating Scale), anxiety (Hamilton Anxiety Rating Scale), and neuropsychological battery [ Time Frame: Measured at baseline, monthly for 4 months, then every 3 months for 9 months, and then every 6 months for up to 4 years ] [ Designated as safety issue: Yes ]
  

Obsessive-compulsive disorder (OCD) is a chronic and debilitating illness that affects between 2% and 3% of adults in the United States. People with OCD often experience persistent unwanted thoughts and carry out ritual-like behaviors to rid themselves of these obsessive thoughts. Additionally, OCD symptoms are usually tied with feelings of intense anxiety and functional impairment, making it important for people with OCD to seek effective treatment. Although there are currently many treatment options for OCD, including psychotherapy and medications such as serotonin reuptake inhibitors, between 40% and 60% of people with OCD only partially respond or do not respond at all to these treatment methods. Given the large percentage of people who do not respond to aggressive conventional treatments, alternative options are necessary for people with treatment-resistant OCD. Deep brain stimulation (DBS) is a procedure that involves the use of thin wires to carry electric current to parts of the brain associated with producing OCD symptoms. DBS has been effectively and safely used to treat movement disorders, such as Parkinson's disease, and may be beneficial in reducing OCD symptom severity. This study will evaluate the safety and effectiveness of DBS in treating people with severe and otherwise treatment-resistant OCD.

Study participation through follow-up will last 4 years. Participants will be allowed to remain on any pre-surgical medications or behavioral therapy programs throughout the study. Before surgery, all participants will undergo a 3- to 4-day series of initial tests and examinations that will include a physical and neurological examination; blood and urine screening tests; an electrocardiogram (EKG); an electroencephalography (EEG); and detailed psychological testing, including tests of perception, learning, and memory. The EEGs may be performed again after surgery to measure potential changes in brain electrical activity due to DBS.

On the day of the surgery, participants will take a low dose of anxiety medication, have a metal frame fixed to their heads for support during surgery, and undergo a magnetic resonance imaging (MRI) scan to determine where to place the stimulating wires. After being injected with a local anesthetic, participants will undergo the first part of the operation, which will involve the implantation of neurostimulators in the ventral caudate/ventral striatum brain region. For the second part of the operation, after participants are administered general anesthesia, they will have the implantable neurostimulators (INSs) placed in their chests and the connecting wires to the brain placed under their skin. The entire surgical procedure will take 3 to 4 hours, with a 1- to 2-day post-operative hospital stay for recovery. During the post-operative stay, participants will undergo x-rays and a computed tomography (CT) scan of the head.

Two to 3 weeks after surgery, participants will be divided randomly into either a group that receives DBS immediately or a group that first receives sham DBS and then active DBS after 3 months. The level of stimulation will be adjusted individually and on the basis of each participant's response to the stimulation. Participants will complete rating forms, a clinical evaluation, and a check of the stimulators every month for the first 3 months, then at least every 3 months for the rest of the year, and then every 6 months for the remaining years of the study. On the Year 1 visit, participants will repeat the baseline detailed psychological testing. Periodically throughout the 4-year study, staff will contact participants by phone to ask about OCD symptoms, mood, anxiety, and possible side effects. Also throughout the study, participants will need to have the INSs replaced every 5 to 16 months on average.

Participants will also be invited to participate in a related study that involves positron emission tomography (PET) scanning to determine how the stimulation changes activity in the brain. Participation in the separate PET study is optional and will not affect current study participation.