KEY FEATURES OF OCD

Obsessions

These are unwanted ideas or impulses that repeatedly well up in the mind of the person with OCD. Persistent fears that harm may come to self or a loved one, an unreasonable belief that one has a terrible illness, or an excessive need to do things correctly or perfectly, are common. Again and again, the individual experiences a disturbing thought, such as, "My hands may be contaminated--I must wash them"; "I may have left the gas on"; or "I am going to injure my child." These thoughts are intrusive, unpleasant, and produce a high degree of anxiety. Often the obsessions are of a violent or a sexual nature, or concern illness.

Compulsions

In response to their obsessions, most people with OCD resort to repetitive behaviors called compulsions. The most common of these are washing and checking. Other compulsive behaviors include counting (often while performing another compulsive action such as hand washing), repeating, hoarding, and endlessly rearranging objects in an effort to keep them in precise alignment with each other. These behaviors generally are intended to ward off harm to the person with OCD or others. Some people with OCD have regimented rituals while others have rituals that are complex and changing. Performing rituals may give the person with OCD some relief from anxiety, but it is only temporary.

Insight

People with OCD usually have considerable insight into their own problems. Most of the time, they know that their obsessive thoughts are senseless or exaggerated, and that their compulsive behaviors are not really necessary. However, this knowledge is not sufficient to enable them to stop obsessing or the carrying out of rituals.

Resistance

Most people with OCD struggle to banish their unwanted, obsessive thoughts and to prevent themselves from engaging in compulsive behaviors. Many are able to keep their obsessive-compulsive symptoms under control during the hours when they are at work or attending school. But over the months or years, resistance may weaken, and when this happens, OCD may become so severe that time-consuming rituals take over the sufferers' lives, making it impossible for them to continue activities outside the home.

Shame and Secrecy

OCD sufferers often attempt to hide their disorder rather than seek help. Often they are successful in concealing their obsessive-compulsive symptoms from friends and coworkers. An unfortunate consequence of this secrecy is that people with OCD usually do not receive professional help until years after the onset of their disease. By that time, they may have learned to work their lives--and family members' lives--around the rituals.

Long-lasting Symptoms

OCD tends to last for years, even decades. The symptoms may become less severe from time-to-time, and there may be long intervals when the symptoms are mild, but for most individuals with OCD, the symptoms are chronic.

WHAT CAUSES OCD?

The old belief that OCD was the result of life experiences has given way before the growing evidence that biological factors are a primary contributor to the disorder. The fact that OCD patients respond well to specific medications that affect the neurotransmitter serotonin suggests the disorder has a neurobiological basis. For that reason, OCD is no longer attributed to attitudes a patient learned in childhood--for example, an inordinate emphasis on cleanliness, or a belief that certain thoughts are dangerous or unacceptable. Instead, the search for causes now focuses on the interaction of neurobiological factors and environmental influences.

OCD is sometimes accompanied by depression, eating disorders, substance abuse disorder, a personality disorder, attention deficit disorder, or another of the anxiety disorders. Co-existing disorders can make OCD more difficult both to diagnose and to treat.

In an effort to identify specific biological factors that may be important in the onset or persistence of OCD, NIMH-supported investigators have used a device called the positron emission tomography (PET) scanner to study the brains of patients with OCD. Several groups of investigators have obtained findings from PET scans suggesting that OCD patients have patterns of brain activity that differ from those of people without mental illness or with some other mental illness. Brain-imaging studies of OCD showing abnormal neurochemical activity in regions known to play a role in certain neurological disorders suggest that these areas may be crucial in the origins of OCD. There is also evidence that medications and cognitive/behavior therapy induce changes in the brain coincident with clinical improvement.

A graphic of Normal and OCD PET scans showing brain activity in the brain of a person with OCD and the brain of a person without OCD. (Source: Lewis Baxter, UCLA Center for Health Sciences, Los Angeles, CA.) In OCD, there is increased activity in a region of the brain called the frontal cortex.)

Symptoms of OCD are seen in association with some other neurological disorders. There is an increased rate of OCD in people with Tourette's syndrome, an illness characterized by involuntary movements and vocalizations. Investigators are currently studying the hypothesis that a genetic relationship exists between OCD and the tic disorders. Another illness that may be linked to OCD is trichotillomania (the repeated urge to pull out scalp hair, eyelashes, or eyebrows). Genetic studies of OCD and other related conditions may enable scientists to pinpoint the molecular basis of these disorders.