Obsessive-compulsive disorder (OCD) is marked by recurrent, repetitive thoughts (obsessions), behaviors (compulsions), or both. People with OCD recognize that their obsessions and compulsions are unreasonable, unnecessary, intrusive, and sometimes even foolish, yet they cannot resist them. Regardless of whether a person suffers from obsessions, compulsions, or both, the condition interferes with day-to-day activities and relationships with others.

Obsessions are defined as recurring and persistent thoughts, ideas, images, or impulses, sometimes of an aggressive nature, that seem to invade a person's consciousness. The sufferer will try to suppress or ignore these uncomfortable thoughts, often recognizing that they are unrealistic.

Common obsessions are fear of contamination from germs, thoughts of violent behavior (such as killing a family member), fear of making a mistake or of harming oneself or others, and a constant need for reassurance.

Compulsions are ritualistic, repetitive, and purposeful behaviors that are performed according to certain rules or stereotypical patterns. The behavior, although clearly excessive, temporarily relieves the tension and discomfort brought on by the obsessive thoughts.

Common compulsions are rechecking to be sure doors are locked, windows are closed, or an appliance is turned off; excessive neatness and organization; and repetitive hand washing that accompanies an obsession with dirt and germs.

OCD occurs in about 2.2 million adult Americans (1 percent of the adult population) each year and affects men and women equally. It most often starts in the teens or early 20s. Embarrassed and upset by their behavior, most sufferers try to keep it a secret. Those with mild OCD often manage to function with only minimal interference in their daily lives. But in people with more pronounced OCD, obsessive thoughts or compulsive behaviors may be frequent or distressing enough to become incapacitating.

Probably the most common OCD complication is depression; another is marked interference with social and work behaviors. Although some people with OCD experience spontaneous remission, in most the illness has an episodic course with periods of partial remission. In about 10 percent of sufferers, the course of OCD is chronic and unchanged.

Publication Review By: Karen L. Swartz, M.D.

Published: 07 Mar 2011

Last Modified: 03 Feb 2015