Obsessive-compulsive disorder (OCD) is a type of anxiety disorder. People with anxiety disorders cannot stop worrying. In OCD, people have intense, repetitive thoughts, images, or impulses that are frightening, absurd, or unusual. These are called obsessions. Typical obsessions include fears of dirt, germs, contamination, and violent or aggressive impulses. People with obsessive-compulsive disorder may have an intense preoccupation with order and symmetry, or be unable to throw anything away. To reduce the anxiety caused by their irrational thoughts, people with OCD perform ritualized actions, known as compulsions, that also are usually bizarre and irrational. Examples are repeated hand-washing, constant counting or arranging of items, and checking over and over again to make sure an appliance is turned off. As the person performs these acts, he may feel temporarily better, but there is no long-lasting sense of satisfaction or completion after the act is performed. Often, a...