Overview

Obsessive-compulsive disorder (OCD) is a common, chronic, and long-lasting disorder in which a person has uncontrollable, reoccurring thoughts (“obsessions”) and/or behaviors (“compulsions”) that he or she feels the urge to repeat over and over.

Signs and Symptoms
People with OCD may have symptoms of obsessions, compulsions, or both. These symptoms can interfere with all aspects of life, such as work, school, and personal relationships.

Obsessions are repeated thoughts, urges, or mental images that cause anxiety. Common symptoms include:

• Fear of germs or contamination
• Unwanted forbidden or taboo thoughts involving sex, religion, or harm
• Aggressive thoughts towards others or self
• Having things symmetrical or in a perfect order

Compulsions are repetitive behaviors that a person with OCD feels the urge to do in response to an obsessive thought. Common compulsions include:

• Excessive cleaning and/or handwashing
• Ordering and arranging things in a particular, precise way
• Repeatedly checking on things, such as repeatedly checking to see if the door is locked or that the oven is off
• Compulsive counting

Not all rituals or habits are compulsions. Everyone double checks things sometimes. But a person with OCD generally:

• Can’t control his or her thoughts or behaviors, even when those thoughts or behaviors are recognized as excessive
• Spends at least 1 hour a day on these thoughts or behaviors
• Doesn’t get pleasure when performing the behaviors or rituals, but may feel brief relief from the anxiety the thoughts cause
• Experiences significant problems in their daily life due to these thoughts or behaviors

Some individuals with OCD also have a tic disorder. Motor tics are sudden, brief, repetitive movements, such as eye blinking and other eye movements, facial grimacing, shoulder shrugging, and head or shoulder jerking. Common vocal tics include repetitive throat-clearing, sniffing, or grunting sounds.

Symptoms may come and go, ease over time, or worsen. People with OCD may try to help themselves by avoiding situations that trigger their obsessions, or they may use alcohol or drugs to calm themselves. Although most adults with OCD recognize that what they are doing doesn’t make sense, some adults and most children may not realize that their behavior is out of the ordinary. Parents or teachers typically recognize OCD symptoms in children.

If you think you have OCD, talk to your health care provider about your symptoms. If left untreated, OCD can interfere in all aspects of life.

Risk Factors

OCD is a common disorder that affects adults, adolescents, and children all over the world. Most people are diagnosed by about age 19, typically with an earlier age of onset in boys than in girls, but onset after age 35 does happen. For statistics on OCD in adults, please see the NIMH Obsessive-Compulsive Disorder webpage.
The causes of OCD are unknown, but risk factors include:

Genetics
Twin and family studies have shown that people with first-degree relatives (such as a parent, sibling, or child) who have OCD are at a higher risk for developing OCD themselves. The risk is higher if the first-degree relative developed OCD as a child or teen. Ongoing research continues to explore the connection between genetics and OCD and may help improve OCD diagnosis and treatment.

Brain Structure and Functioning
Imaging studies have shown differences in the frontal cortex and subcortical structures of the brain in patients with OCD. There appears to be a connection between the OCD symptoms and abnormalities in certain areas of the brain, but that connection is not clear. Research is still underway. Understanding the causes will help determine specific, personalized treatments to treat OCD.

Environment
An association between childhood trauma and obsessive-compulsive symptoms has been reported in some studies. More research is needed to understand this relationship better.
In some cases, children may develop OCD or OCD symptoms following a streptococcal infection—this is called Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS). For more information, please read NIMH’s fact sheet on PANDAS.