Safety and Effectiveness of Gamma Capsulotomy in Intractable OCD

Inclusion criteria

• OCD, diagnosed by Structured Clinical Interview for DSM-IV (SCID-IV), judged of disabling severity with a Yale-Brown Obsessive Compulsive Scale (YBOCS) score of at least 30 and a Social and Occupational Functioning Assessment Scale (SOFAS) score of 45 or less.
• Persistence of severe symptoms and impairment for five or more years despite: 1. at least three adequate (≥3 months at the maximum tolerated dose) serotonin transporter inhibitor trials (fluoxetine, sertraline, fluvoxamine, paroxetine, citalopram, escitalopram, or clomipramine) alone or in combination with, 2. adequate behavior therapy (≥20 sessions of expert exposure and response prevention), and 3. augmentation of one of the selective SRIs with clomipramine, a neuroleptic, and clonazepam.
• Age between 18 and 65 years.
• Able to understand and comply with instructions.
• Able to give fully informed, written consent in the judgment of the Consent Monitor.
• Either drug free or on a stable drug regimen for at least 6 weeks.
• Good general health.
• A family member or significant other is available and willing to communicate with the research team if the patient's clinical status worsens.
• The local referring psychiatrist is willing to provide ongoing care.

Exclusion criteria

• Current or past psychotic disorder.
• Full-scale IQ below 85.
• A clinical history of bipolar mood disorder.
• Any current clinically significant neurological disorder or medical illness affecting brain function, other than tic disorders or Tourette syndrome.
• Any clinically significant abnormality on preoperative magnetic resonance imaging (MRI).
• Inability to undergo presurgical MRI (cardiac pacemaker, pregnancy, metal in body, severe claustrophobia.
• Current or unstably remitted substance abuse, dependence, or a positive urine toxicology screen.
• Pregnancy and women of childbearing age not using effective contraception.
• Unable to adhere to operational and administrative study requirements (in the investigators' judgment).
• Clinical history of severe personality disorder.
• Imminent risk of suicide (in the investigators' judgment).