People with obsessive-compulsive disorder (OCD) suffer intensely from recurrent, unwanted thoughts (obsessions) or rituals (compulsions), which they feel they cannot control. Rituals such as handwashing, counting, checking, or cleaning are often performed with the hope of preventing obsessive thoughts or making them go away. Performing these rituals, however, provides only temporary relief, and not performing them markedly increases anxiety. Left untreated, obsessions and the need to perform rituals can take over a person's life. OCD is a relapsing illness. Fortunately, through research supported by the National Institute of Mental Health (NIMH) and by industry, effective treatments have been developed to help people with OCD.

How Common Is OCD?

About 2.3% of the U.S. population ages 18 to 54 - approximately 3.3 million Americans - has OCD in a given year.

OCD affects men and women at the same rate.

OCD typically begins during adolescence or early childhood; at least one-third of the cases of adult OCD began in childhood.

What Causes OCD?

There is growing evidence that OCD represents abnormal functioning of brain circuitry, probably involving a part of the brain called the striatum. OCD is not caused by family problems or attitudes learned in childhood, such as an inordinate emphasis on cleanliness, or a belief that certain thoughts are dangerous or unacceptable. Brain imaging studies using a technique called positron emission tomography (PET) have compared people with and without OCD. Those with OCD have patterns of brain activity that differ from people with other mental illnesses or people with no mental illness at all. In addition, PET scans show that in patients with OCD, both behavioral therapy and medication produce changes in the striatum. This is graphic evidence that both psychotherapy and medication affect the brain.

What Treatments Are Available for OCD?

Treatments for OCD have been developed through research supported by the NIMH and other research institutions. These treatments, which combine medications and behavioral therapy (a specific type of psychotherapy), are often effective.

A type of behavioral therapy known as "exposure and response prevention" is very useful for treating OCD. In this approach, a person is deliberately and voluntarily exposed to whatever triggers the obsessive thoughts, and then is taught techniques to avoid performing the compulsive rituals and to deal with the anxiety.

Several medications have been proven effective in helping people with OCD: clomipramine, fluoxetine, fluvoxamine, sertraline, and paroxetine. If one drug is not effective, others should be tried. A number of other medications are currently being studied.

Can People With OCD Also Have Other Illnesses?

OCD is sometimes accompanied by depression, eating disorders, substance abuse, attention deficit hyperactivity disorder, or other anxiety disorders. When a person also has other disorders, OCD is often more difficult to diagnose and treat. Symptoms of OCD can also coexist and may even be part of a spectrum of other brain disorders, such as Tourette's syndrome. Appropriate diagnosis and treatment of other disorders are important to successful treatment of OCD.

National Institute of Mental Health
Publication No. OM-99 4154 (Revised)
Updated: February 21, 2003