What Is It?

In obsessive-compulsive disorder (OCD) a person is troubled by a pattern of intrusive, distressing thoughts and repetitive behaviors.

Although the exact cause of OCD remains a mystery, doctors believe there are changes in the functioning of brain pathways that are involved with judgment, planning and body movements. Environmental influences, such as family relationships or stressful events, have an impact, too.

OCD affects an estimated 2% to 3% of people in the United States. The percentage is about the same in Canada, Korea, New Zealand and parts of Europe.

About two-thirds of people with OCD have the first symptoms before they are 25 years old, while only 15% develop symptoms after age 35. There is strong evidence that the illness has a genetic (inherited) basis, since about 35% of people with OCD have a close relative who also has the condition. Although 50% to 70% of patients first develop OCD after a stressful life event - such as a pregnancy, a job loss or a death in the family - scientists still do not understand exactly how or why stress seems to trigger the symptoms of this illness.

Sometimes, people with OCD manage to live with their obsessions without giving any external sign that they are suffering. Usually, however, they will try to relieve their obsessions by performing some type of compulsion: a persistent, repeated ritual that is aimed at soothing their fears. For example, a woman who has the obsession that her hands are dirty may develop the compulsion to wash them 50 times a day. A man who fears that his front door is unlocked may feel compelled to check the lock 10 or 20 times each night. Although it is also possible for a person with OCD to perform compulsive acts that are not triggered by obsessions, this is not very common.

Symptoms

Two major symptoms of OCD are obsessions and compulsive rituals.

Obsessions are persistent, repeated, anxiety-provoking thoughts that intrude into everyday life and cause feelings of distress. Although obsessions can vary from person to person, they often center on one or more of the following issues: