Obsessive-compulsive disorder (OCD) is a usually chronic, frequently disabling mental disorder.

OCD is the fourth most common mental disorder in the U. S., with a mean 1-year prevalence of 1.3% and a mean lifetime prevalence of 2.3%. It affects women slightly more often than men, but men tend to have an earlier onset of the disorder.

The National Advisory Mental Health Council of the federal government's National Institute of Mental Health classifies OCD as a severe mental disorder. OCD is estimated to account for 5.7% of the cost of all mental illness.

OCD usually responds reasonably well to treatment with medications or cognitive-behavior therapy or a combination of these approaches.

The primary anti-OCD medications all enhance the function of the neurochemical messenger called serotonin, which carries messages between nerve cells in the brain. Each available serotonin reuptake inhibitor (SRI), citalopram, clomipramine, sertraline, fluoxetine, fluvoxamine and paroxetine, benefits about 45% to 60% of OCD patients.

The response rates to the serotonin/norepinephrine reuptake inhibitor, venlafaxine, appears similar, but not much data is available. We cannot predict which patient will respond to which drug or fail to respond to all 7 drugs, and each drug requires a treatment trial of 8 to 10 weeks.

Estimates of the proportion of patients whose OCD does not respond satisfactorily to oral medications range from 20% to 40%.

Controlled trials of behavior therapy (exposure and response prevention) indicate that 20% to 30% of OCD patients are unresponsive to this treatment and an additional 20% drop out without having attained much benefit. The likelihood that behavior therapy will benefit patients unresponsive to medications is unknown.

OCD responds slowly to orally administered SRIs. After 4 weeks of treatment, mean scores on the standard rating scale, the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), fall only about 20%. A clinically substantial response (a Y-BOCS decrease of >= 35%) usually takes about 6 weeks or more to develop.

Many medication augmentation strategies (combinations of other drugs with SRIs) for treatment resistant OCD have some support in the scientific literature. The Stanford OCD Research Program is investigating several of them. Since our preliminary double-blind research on 15 patients suggests that intravenous Anafranil is effective for unresponsive patients, we are now conducting a larger controlled study of this as well as other novel approaches to treatment-unresponsive OCD (call 650:723-8601 for more information).