Obsessive-compulsive disorder (OCD) is a mental disorder in which people experience unwanted and repeated thoughts, feelings, images, or sensations (obsessions) and engage in behaviors or mental acts (compulsions) in response. Often a person with OCD carries out the compulsions to temporarily eliminate or reduce the impact of obsessions, and not performing them causes distress. OCD varies in severity, but if left untreated, it can limit one's ability to function at work, school, or home.
OCD is estimated to affect more than 2 percent of U.S. adults at some point in their lives, and the problem can be accompanied by other conditions, including anxiety disorders, depression, and eating disorders. It typically first appears in childhood, adolescence, or early adulthood.
- Obsessions are recurring thoughts, urges, or images that are experienced as intrusive and unwanted and, for most people, cause anxiety or distress. The individual tries to ignore them, suppress them, or neutralize them with with a different thought or action.
- Compulsions are repetitive behaviors or mental acts that one feels compelled to do in response to an obsession or based on strict rules. They are meant to counter anxiety or distress or to prevent a feared event or situation, but they are not realistically connected to these outcomes, or they are excessive.
These obsessions or compulsions take up more than one hour a day or cause clinically significant distress or impairment for the individual. For a diagnosis of OCD, they must not be better explained by the effects of a substance or by another mental disorder or medical condition.
The specific details of obsessions can vary widely: They may include thoughts about contamination, a desire for order, or taboo thoughts related to sex, religion, and harm to oneself or others.
In response to their obsessions, most people with OCD resort to compulsions, which may include behaviors such as washing; rearranging or counting objects; seeking reassurance; or checking (to see if an oven is turned off or a door is locked, for example). They can also include mental acts that are not outwardly observable. Compulsions may temporarily relieve feelings that stem from an obsession, including anxiety, distress, or the sense that something is not right.
People with OCD may also avoid people, places, or things that may trigger obsessions and compulsions. They also often have dysfunctional beliefs that can include a heightened sense of responsibility, intolerance of uncertainty, perfectionism, or an exaggerated view of the significance of troubling thoughts.
Individuals with OCD vary in their degree of insight into the condition. Someone with good insight may recognize that the OCD-related beliefs (that performing a compulsion will prevent a terrible event, for example) are not actually true; someone with poorer insight may think such beliefs are true or are likely to be true.
The severity of symptoms may vary over time, but the disorder can persist for years or decades if it is not treated.
People with OCD frequently also experience another form of mental illness. An estimated three quarters of adults with OCD are diagnosed, at some point in their lives, with an anxiety disorder (such as generalized anxiety disorder or panic disorder); more than half are diagnosed with a depressive or bipolar disorder; and up to 30 percent have a tic disorder, according to DSM-5. Those with OCD may also experience a range of other conditions, including related disorders such as body dysmorphic disorder, trichotillomania, and excoriation disorder.
While the causes of obsessive-compulsive disorder are not fully understood, there are both genetic and environmental risk factors. People who have a parent, sibling, or child with OCD are at greater risk of having it themselves, and studies with twins confirm the role of genetic influence in the development of the disorder. Childhood physical or sexual abuse and other traumatic events are associated with greater risk.
In some children, a streptococcal infection precedes the sudden development or worsening of OCD symptoms, a condition called Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS).
Research-backed forms of therapy for treating OCD include Cognitive Behavioral Therapy (CBT), which is used to treat a range of disorders, and a specific type of CBT called Exposure and Response Prevention (ERP). In ERP, a person with OCD, initially guided by a therapist, is exposed to thoughts, things, or situations that produce anxiety or lead to obsessions and compulsions and, in doing so, learns to not engage in habitual compulsions. This approach aims to gradually reduce the anxiety prompted by such thoughts and encounters so that the individual can better manage OCD symptoms.
Medications called serotonin reuptake inhibitors (SRIs) and selective serotonin reuptake inhibitors (SSRIs) are also used to treat OCD. These include the older antidepressant clomipramine and more recently developed drugs such as fluoxetine, fluvoxamine, and sertraline. SSRIs are thought to work by increasing the amount of the neurotransmitter serotonin in the brain, and they are commonly prescribed for other conditions, including depressive and anxiety disorders. They may take as long as 12 weeks to produce an improvement in symptoms when used to treat OCD.