Understanding Obsessive-Compulsive Disorder -- the Basics

What Is Obsessive-Compulsive Disorder?

Obsessive-compulsive disorder (OCD) at one time was classified as a type of anxiety disorder, but it is now thought to be its own unique condition. It goes beyond the ordinary "double-checking" and worrying that all of us do from time to time. Everybody sometimes wants to make sure the doors are locked or the oven is off. For people with OCD, these thoughts and behaviors are so magnified that they interfere with everyday routines, jobs, and relationships. For example, people with OCD have been known to wash their hands for eight hours in a day or reorganize their entire household every day.

Obsessive-compulsive disorder doesn't go away by itself. It can't be controlled by willpower alone. People with OCD are trapped in patterns of senseless thoughts and behaviors beyond their control. Even after long periods of relative normalcy, obsessive thoughts and compulsive actions may return without apparent cause.

Obsessions are disturbing recurrent ideas or impulses that intrude on a person's mind. They may take the form of fears that harm will come to oneself or to a loved one. They may be an extreme worry about getting contaminated, a dread of illness, or an overpowering need to do things perfectly. Sometimes these obsessions involve religious, sexual, or violent themes.

Compulsions are repetitive actions driven by obsessions. The most common obsessions are contamination, doubt, and loss. These result in the common compulsions of hand washing, checking, and hoarding. Some obsessive-compulsive actions, such as uncontrollable counting or praying, aren't obvious to others. People with OCD often fear that if they do not perform these acts, something bad will happen to them or to others.

Because obsessions and compulsions may take hold gradually, people often fail to recognize that they are suffering from a form of mental illness. When OCD eventually produces symptoms that interfere with daily life, people may try to hide their compulsions from others and attempt to deal with them by using willpower. People with OCD often feel embarrassed about their obsessive thoughts or compulsions. They may avoid talking about their symptoms, even to their health care provider.


Although OCD can appear at any age, it most often begins during adolescence. According to the National Institute of Mental Health, one-third of adults with OCD developed symptoms in childhood and the average age of onset is 19. Some researchers think OCD that develops in childhood is different from OCD that appears for the first time in adults. Men and women are affected equally. In the U.S., between 2% and 3% of the population experiences some form of OCD during their lives.

Obsessive-compulsive features are also found in Tourette's syndrome, depression, and schizophrenia.

What Causes OCD?

In ancient times, obsessive or compulsive behavior was thought to indicate demonic possession. Exorcism was one of the earliest -- and least successful -- forms of treatment. The traditional hypothesis from Freudian theory holds that obsessions reflect unconscious desires from an earlier stage of development. Modern understanding about OCD suggests that there is a disturbance of brain circuitry between the frontal lobe and subcortical areas that may also involve dysregulation of brain chemicals such as serotonin, especially in people who may have a genetic vulnerability to the disorder.

People with OCD sometimes have other psychological problems such as depression, eating disorders, substance abuse, personality disorders, attention-deficit/hyperactivity disorder (ADHD), or anxiety. They also may suffer from obsessively pulling out their hair (called trichotillomania), preoccupation with imperfections they see in their appearance (body dysmorphic disorder), and the belief that they have a medical illness (hypochondria). These other problems can make OCD much more difficult to diagnose and treat.

WebMD Medical Reference Reviewed by Joseph Goldberg, MD on February 11, 2017



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