Obsessive-Compulsive Disorder, a mental disorder in which a person has a repeated obsession that typically leads to a repeated compulsion. For example, a man may be obsessed with the belief that his hands are contaminated with germs. The anxiety resulting from this obsession causes him to develop a compulsion of frequent hand-washing. The compulsion may be so strong that it continues even after the hands have become raw from excessive washing. Obsessive-compulsive disorder is treated with psychotherapy and drugs.
The disorder usually begins in adolescence or early adulthood and often becomes worse with age. Psychiatrists believe that it is caused primarily by emotional stress. Obsessive-compulsive disorder seems to run in families.