What is obsessive-compulsive disorder?

Obsessive-compulsive disorder (OCD), one of the anxiety disorders, is a potentially disabling illness that traps people in endless cycles of repetitive thoughts and behaviors. People with OCD are plagued by recurring and distressing thoughts, fears, or images (obsessions) they cannot control. The anxiety (nervousness) produced by these thoughts leads to an urgent need to perform certain repetitive behaviors, rituals, or routines (compulsions). The compulsions are performed in an attempt to prevent the obsessive thoughts or make them go away; not performing the rituals increases the anxiety.

Performing the compulsions may lesson or relieve the anxiety temporarily; however, the person is “compelled” to perform the behaviors again when the obsessions return. This OCD cycle may progress to the point of taking up hours of the person’s day and significantly interfering with normal activities. People with OCD are often aware that their obsessions and compulsions are senseless or unrealistic, but they cannot stop themselves.

What are the symptoms of obsessive-compulsive disorder?

The symptoms of OCD may vary. Common obsessions include:

  • Fear of dirt or contamination by germs
  • Fear of causing harm to another
  • Fear of making a mistake
  • Fear of being embarrassed or behaving in a socially unacceptable manner
  • Fear of thinking evil or sinful thoughts
  • Need for order, symmetry, or exactness
  • Excessive doubt/the need for constant reassurance

Common compulsions include:

  • Repeatedly bathing, showering, or washing hands
  • Refusing to shake hands or touch doorknobs
  • Repeatedly checking things, such as locks or stoves
  • Constant counting, mentally or aloud, while performing routine tasks
  • Constantly arranging things in a certain way
  • Eating foods in a specific order
  • Being stuck on words, images, or thoughts, usually disturbing, that won’t go away
  • Repeating specific words, phrases, or prayers
  • Needing to perform tasks a certain number of times
  • Collecting or hoarding items with no apparent value

What causes obsessive-compulsive disorder?

Although the exact cause of OCD is not fully understood, studies have shown that a combination of biological and environmental factors may be involved.

Biological factors

The brain is a very complex structure. It contains billions of nerve cells—called neurons—that must communicate and work together for the body to function normally. The neurons communicate via electrical signals. Special chemicals, called neurotransmitters, help move these electrical messages from neuron to neuron. Research has found that patients with OCD have over activity in specific portions of their brain circuits. These circuits become even more active when the patient is experiencing their OCD symptoms. Effective treatment with either medication or behavior therapy can normalize this over activity.

Environmental factors

People with a tendency toward developing OCD may be impacted by environmental stressors. Certain environmental factors also might cause a worsening of symptoms. These factors include:

  • Abuse
  • Changes in living situation
  • Illness
  • Death of a loved one
  • Work- or school-related changes or problems
  • Relationship concerns

How common is obsessive-compulsive disorder?

OCD afflicts about 2.2 million adults in the United States. The disorder usually first appears in childhood, adolescence or early adulthood. It occurs about equally in men and women, and affects people of all races and socioeconomic backgrounds.

How is obsessive-compulsive disorder diagnosed?

There is no laboratory test for OCD. The provider bases the diagnosis on an assessment of the patient’s symptoms, and the impact on the patient’s overall functioning. Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-V) is used as a guideline. DSM-V, compiled by the American Psychiatric Association, is the standard reference manual for the diagnosis of recognized mental illnesses in the United States.

How is obsessive-compulsive disorder treated?

OCD will not go away by itself, so it is important to seek treatment. The person might be referred to a health care professional who is specially trained to diagnose and treat mental illnesses.

The most effective approach to treating OCD combines medications with cognitive-behavior therapy.

  • Cognitive-behavior therapy: (CBT)-CBT focuses on reducing the exaggerated or catastrophic thinking that often occurs in people with OCD. The goal is to assist persons with OCD in confronting their anxiety producing beliefs without performing the compulsive behaviors.
  • Medication therapy: Selective serotonin reuptake inhibitors (SSRIs) is a family of medications that work by increasing and sustaining the levels of serotonin in the brain. As mentioned above, low levels of serotonin are linked to OCD. The SSRIs approved in the United States for the treatment of OCD include fluoxetine (Prozac®), fluvoxamine (Luvox®), Paroxetine (Paxil®), sertraline (Zoloft®) and citalopram (Celexa®). Another antidepressant medication, clomipramine (Anafranil®), is also approved for treating OCD.

In severe cases of OCD and in people who do not respond to treatment, (ECT) or surgery might be used to treat OCD. During ECT, electrodes are attached to the patient’s head, and a series of electric shocks are delivered to the brain, which induce seizures. The seizures cause the release of neurotransmitters in the brain.

What is the outlook for people with obsessive-compulsive disorder?

In most cases, OCD can be successfully treated with medication, CBT or both. With ongoing treatment, most people can achieve long-term relief from symptoms and return to normal or near-normal functioning.

Can obsessive-compulsive disorder be prevented?

OCD cannot be prevented. However, early diagnosis and treatment can help reduce the time a person spends battling this disorder.


  • The National Institute of Mental Health (NIMH). Obsessive-Compulsive Disorder, OCD Accessed: 6/2/2014
  • Eisendrath SJ, Lichtmacher JE. Chapter 25. Psychiatric Disorders. In: Papadakis MA, McPhee SJ, Rabow MW. eds. CURRENT Medical Diagnosis & Treatment 2014. New York, NY: McGraw-Hill; 2014. library.ccf.org Accessed: 6/2/2014
  • Bipolar and Related Disorders. In: Diagnostic and Statistical Manual of Mental Disorders, DSM-5. American Psychiatric Publishing, Incorporated; 2013.

© Copyright 1995-2016 The Cleveland Clinic Foundation. All rights reserved.

Can't find the health information you’re looking for?

This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 6/2/2014...#9490