Obsessive-compulsive disorder is an anxiety disorder in which people have thoughts, feelings, ideas, sensations (obsessions), or behaviors that make them feel driven to do something (compulsions). A person may have both obsessions and compulsions.

Obsessive-compulsive disorder (OCD) is more common than was once thought. Most people who develop it show symptoms by age 30.

There are several theories about the cause of OCD, but none have been confirmed. Some reports have linked OCD to head injury and infections. Several studies have shown that there are brain abnormalities in patients with OCD, but more research is needed.

About 20% of people with OCD have tics, which suggests the condition may be related to Tourette syndrome. However, this link is not clear.

• Obsessions or compulsions that are not due to medical illness or drug use
• Obsessions or compulsions that cause major distress or interfere with everyday life

An example of obsessive-compulsive disorder is excessive, repeated handwashing to ward off infection.

The person usually recognizes that the behavior is excessive or unreasonable.

Your own description of the behavior can help diagnose the disorder. A physical exam can rule out physical causes, and a psychiatric evaluation can rule out other mental disorders.

Questionnaires, such as the Yale-Brown Obsessive Compulsive Scale, can help diagnose OCD and track the progress of treatment.

OCD is treated using medications and therapy.

The first medication usually considered is a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI). These drugs include:

• Citalopram (Celexa)
• Fluoxetine (Prozac)
• Fluvoxamine (Luvox)
• Paroxetine (Paxil)
• Sertraline (Zoloft)

If an SSRI does not work, the doctor may prescribe an older antidepressant called clomipramine. Clomipramine is the oldest medication for OCD. It works better than SSRI antidepressants in treating the condition, but it has unpleasant side effects, including:

• Difficulty starting urination
• Drop in blood pressure when rising from a seated position
• Dry mouth
• Sleepiness

In some cases, an SSRI and clomipramine may be combined. Other medications such as benzodiazepines may offer some relief from anxiety, but they are generally used only with the more reliable treatments.

Psychotherapy is used to:

• Provide effective ways of reducing stress
• Reduce anxiety
• Resolve inner conflicts

Behavioral therapies may include:

• Exposure/response prevention: You are exposed many times to a situation that triggers anxiety symptoms, and learn to resist the urge to perform the compulsion.
• Thought-stopping: You learn to stop unwanted thoughts and focus attention on relieving anxiety.

OCD is a long-term (chronic) illness with periods of severe symptoms followed by times of improvement. However, a completely symptom-free period is unusual. Most people improve with treatment.

Long-term complications of OCD have to do with the type of obsessions or compulsions. For example, constant handwashing can cause skin breakdown. However, OCD does not usually progress into another disease.

Call for an appointment with your health care provider if your symptoms interfere with daily life, work, or relationships.

There is no known prevention for this disorder.

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Denys D. Pharmacotherapy of obsessive-compulsive disorder and obsessive-compulsive spectrum disorders. Psychiatr Clin North Am. 2006;29:553-584.