Obsessive-compulsive disorder

Obsessive Compulsive Disorder 831
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Obsessive-compulsive disorder (OCD) is currently classified as an anxiety disorder marked by the recurrence of intrusive or disturbing thoughts, impulses, images or ideas (obsessions) accompanied by repeated attempts to suppress these thoughts through the performance of certain irrational and ritualistic behaviors or mental acts (compulsions). The obsessions and compulsions take up large amounts of the patient's time (an hour or longer every day) and usually cause significant emotional distress for the patient and difficulties in his or her relationships with others.

Some researchers have questioned whether OCD really belongs with the other anxiety disorders. They think that it should be grouped with the spectrum of such obsessive-compulsive disorders as Tourette's syndrome, which are known to have biological causes.

OCD should not be confused with obsessive-compulsive personality disorder even though the two disorders have similar names. Obsessive-compulsive personality disorder is not characterized by the presence of obsessions and compulsions; rather, it is a lifelong pattern of insistence on control, orderliness, and perfection that begins no later than the early adult years. It is possible, however, for a person to have both disorders.


Obsessive-compulsive disorder is a mental disorder with two components: obsessions, which consist of thoughts, impulses, or mental images; and compulsions, which are repetitive behaviors that the person feels driven to perform in response to the obsessions. In some cases, the compulsion may represent a strict rule that the patient must apply rigidly in every situation (tying one's shoes a certain number of times, for example) in order to feel "right." The exact content of obsessions varies from person to person, although certain themes are common. People with OCD experience their disturbing thoughts and images as intrusive and troublesome, but they recognize that their thoughts are products of their own minds. Obsessive thoughts are different from worries about such real-life problems as losing one's job or bad grades in school. In addition, obsessive thoughts are not usually related to any real-life problems.

The most common types of obsessions in persons with OCD in Western countries are:

  • fear of contamination (impurity, pollution, badness)
  • doubts (worrying about whether one has omitted to do something)
  • an intense need to have or put things in a particular order
  • aggressive or frightening impulses
  • recurrent sexual thoughts or images

It is important to understand that patients diagnosed with OCD do not perform their compulsions for pleasure or satisfaction. A compulsive behavior becomes linked to an obsessional thought because the behavior lowers the level of anxiety produced by the obsession(s).

The most common compulsions in Western countries are:

  • washing/cleaning
  • counting
  • hoarding
  • checking
  • putting objects in a certain order
  • repeated "confessing" or asking others for assurance
  • repeated actions
  • making lists

Although descriptions of patients with OCD have been reported since the fifteenth century in religious and psychiatric literature, the condition was widely assumed to be rare until very recently. Epidemiological research since 1980 has now identified OCD as the fourth most common psychiatric illness, after phobias, substance use disorders, and major depressive disorders. OCD is presently classified as a form of anxiety disorder, but current studies indicate that it results from a combination of psychological, neurobiological, genetic, and environmental causes.

Causes and symptoms


PSYCHOSOCIAL. In the early part of the century, Sigmund Freud theorized that OCD symptoms were caused by punitive, rigid toilet-training practices that led to internalized conflicts. Other theorists thought that OCD was influenced by such wider cultural attitudes as insistence on cleanliness and neatness, as well as by the attitudes and parenting style of the patient's parents. Cross-cultural studies of OCD indicate that, while the incidence of OCD seems to be about the same in most countries around the world, the symptoms are often shaped by the patient's culture of origin. For example, a patient from a Western country may have a contamination obsession that is focused on germs, whereas a patient from India may fear contamination by touching a person from a lower social caste.

Studies of families with OCD members indicate that the particular expression of OCD symptoms may be affected by the responses of other people. Families with a high tolerance for the symptoms are more likely to have members with more extreme or elaborate symptoms. Problems often occur when the OCD member's obsessions and rituals begin to control the entire family.

BIOLOGICAL. There is considerable evidence that OCD has a biological component. Some researchers have noted that OCD is more common in patients who have suffered head trauma or have been diagnosed with Tourette's syndrome. Recent studies using positron emission tomography (PET) scanning indicate that OCD patients have patterns of brain activity that differ from those of people without mental illness or with some other mental illness. Other studies using magnetic resonance imaging (MRI) found that patients diagnosed with OCD had significantly less white matter in their brains than did normal control subjects. This finding suggests that there is a widely distributed brain abnormality in OCD. Some researchers have reported abnormalities in the metabolism of serotonin, an important neurotransmitter, in patients diagnosed with OCD. Serotonin affects the efficiency of communication between the front part of the brain (the cortex) and structures that lie deeper in the brain known as the basal ganglia. Dysfunction in the serotonergic system occurs in certain other mental illnesses, including major depression. OCD appears to have a number of features in common with the so-called obsessive-compulsive spectrum disorders, which include Tourette's syndrome; Sydenham's chorea; eating disorders; trichotillomania ; and delusional disorders.

There appear to be genetic factors involved in OCD. The families of persons who are diagnosed with the disorder have a greater risk of OCD and tic disorders than does the general population. Childhood-onset OCD appears to run in families more than adult-onset OCD, and is more likely to be associated with tic disorders. Twin studies indicate that monozygotic, or identical twins, are more likely to share the disorder than dizygotic, or fraternal twins. The concordance (match) rate between identical twins is not 100%, however, which suggests that the occurrence of OCD is affected by environmental as well as genetic factors. In addition, it is the general nature of OCD that seems to run in families rather than the specific symptoms; thus, one family member who is affected by the disorder may have a compulsion about washing and cleaning while another is a compulsive counter.

Large epidemiological studies have found a connection between streptococcal infections in childhood and the abrupt onset or worsening of OCD symptoms. The observation that there are two age-related peaks in the onset of the disorder increases the possibility that there is a common causal factor. Patients with childhood-onset OCD often have had one of two diseases caused by a group of bacteria called Group A beta-hemolytic streptococci ("strep" throat and Sydenham's chorea) prior to the onset of the OCD symptoms. The disorders are sometimes referred to as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS. It is thought that antibodies in the child's blood cross-react with structures in the basal ganglia, producing or worsening the symptoms of OCD or tic disorders.


The symptoms of OCD should not be confused with the ability to focus on detail or to check one's work that is sometimes labeled "compulsive" in everyday life. This type of attentiveness is an important factor in academic achievement and in doing well in fields that require close attention to detail, such as accounting or engineering. By contrast, the symptoms of OCD are serious enough to interfere with the person's day-to-day functioning. Historical examples of OCD include a medieval Englishman named William of Oseney, who spent twelve hours per day reading religious books in order to be at peace with God; and Freud's Rat Man, a patient who had repeated dreams of cursing Freud and covering him with dung. While the Rat Man was ashamed of these impulses and had no explanation for them, he could not control them.

More recent accounts of OCD symptoms include those of a young man who compulsively touched every electrical outlet as he passed, washed his hands several times an hour, and returned home repeatedly to check that the doors and windows were locked. Another account describes a firefighter who was worried that he had throat cancer. He spent three hours a day examining his throat in the mirror, feeling his lymph nodes, and asking his wife if his throat appeared normal.

Brief descriptions of the more common obsessions and compulsions follow.

CONTAMINATION. People with contamination obsessions are usually preoccupied with a fear of dirt or germs. They may avoid leaving home or allowing visitors to come inside in order to prevent contact with dirt or germs. Some people with contamination obsessions may wear gloves, coats, or even masks if they are forced to leave their house for some reason. Obsessions with contamination may also include abnormal fears of such environmental toxins as lead, asbestos, or radon.

Washing compulsions are commonly associated with contamination obsessions. For example, a person concerned about contamination from the outside may shower and launder all clothing immediately upon coming home. The compulsion may be triggered by direct contact with the feared object, but in many cases, even being in its general vicinity may stir up intense anxiety and a strong need to engage in a washing compulsion. One man who was afraid of contamination could not even take a short walk down the street without experiencing a compulsion to disinfect the soles of his shoes, launder all his clothing, and wash his hands until they were raw after he returned to his apartment.

Washing compulsions may not always be caused by a fear of germs. That is, a need for perfection or for symmetry may also lead to unnecessary washing. In such cases, the individual may be concerned about being "perfectly" clean, or feel that he cannot leave the shower until his left foot has been washed exactly as many times as his right foot. Other people with washing compulsions may be unable to tolerate feeling sweaty or otherwise not clean.

OBSESSIONAL DOUBTING. Obsessional doubting refers to the fear of having failed to perform some task adequately, and that dire consequences will follow as a result. Although the person may try to suppress the worrisome thoughts or images, he or she usually experiences a rising anxiety which then leads to a compulsion to check the task. For example, someone may worry about forgetting to lock the door or turn off the gas burner on the stove and spend hours checking these things before leaving home. In one instance, a man was unable to throw away old grocery bags because he feared he might have left something valuable inside one of them. Immediately after looking into an empty bag, he would again have the thought, "What if I missed something in there?" In many cases, no amount of checking is sufficient to dispel the maddening sense of doubt.

NEED FOR SYMMETRY. Persons suffering from an obsession about symmetry often report feeling acutely uncomfortable unless they perform certain tasks in a symmetrical or balanced manner. Thus, crossing one's legs to the right must be followed by crossing legs to the left; scratching one side of the head must be followed by scratching the other; tapping the wall with a knuckle on the right hand must be followed by tapping with one on the left, etc. Sometimes the person may have a thought or idea associated with the compulsion, such as a fear that a loved one will be harmed if the action is not balanced, but often there is no clearly defined fear, only a strong sense of uneasiness.

AGGRESSIVE AND SEXUAL OBSESSIONS. Aggressive and sexual obsessions are often particularly horrifying to those who experience them. For some people, obsessive fears of committing a terrible act in the future compete with fears that they may already have done something awful in the past. Compulsions to constantly check and confess cause such individuals to admit to evildoing they had no part in, a phenomenon familiar to law enforcement following highly publicized crimes. These obsessions often involve violent or graphic imagery that is upsetting and disgusting to the person, such as rape, physical assault, or even murder. One case study concerned a young woman who constantly checked the news to reassure herself that she had not murdered anyone that day; she felt deeply upset by unsolved murder cases. A middle-aged man repeatedly confessed to having molested a woman at work, despite no evidence of such an action ever occurring in his workplace.

SYMPTOMS IN CHILDREN. Obsessions and compulsions in children are often focused on germs and fears of contamination. Other common obsessions include fears of harm coming to self or others; fears of causing harm to another person; obsessions about symmetry; and excessive moralization or religiosity. Childhood compulsions frequently include washing, repeating, checking, touching, counting, ordering and arranging. Younger children are less likely to have full-blown anxiety-producing obsessions, but they often report a sense of relief or strong satisfaction (a "just right" feeling) from completing certain ritualized behaviors. Since children are particularly skillful in disguising their OCD symptoms from adults, they may effectively hide their disorder from parents and teachers for years.

Unusual behaviors in children that may be signs of OCD include:

  • Avoidance of scissors or other sharp objects. A child may be obsessed with fears of hurting herself or others.
  • Chronic lateness or dawdling. The child may be per forming checking rituals (repeatedly making sure all her school supplies are in her bookbag, for example).
  • Daydreaming or preoccupation. The child may be counting or performing balancing rituals mentally.
  • Spending long periods of time in the bathroom. The child may have a handwashing compulsion.
  • Schoolwork handed in late or papers with holes erased in them. The child may be repeatedly checking and cor recting her work.

For both children and adults, the symptoms of OCD wax and wane in severity; and the specific content of obsessions and compulsions may change over time. The disorder, however, very seldom goes away by itself without treatment. People with OCD in all age groups typically find that their symptoms worsen during major life changes or following highly stressful events.


As noted above, OCD is a relatively common mental disorder, with about 2.3% of the population of the United States being diagnosed with the condition at some point in their lives. As of 2000, the annual social and economic costs of OCD in the United States are estimated at $9 billion. Although the disorder may begin at any age, the typical age of onset is late adolescence to young adulthood, with slightly more women than men being diagnosed with OCD. Interestingly, childhood OCD is more common in males, and the sex ratio does not favor females until adulthood. People with OCD appear to be less likely to marry than persons diagnosed with other types of mental disorders.


OCD is a disorder that may not be diagnosed for years. People who suffer from its symptoms are often deeply ashamed, and go to great lengths to hide their ritualistic behaviors. The disorder may be diagnosed when family members get tired of the impact of the patient's behaviors on their lives, and force the patient to consult a doctor. In other cases, the disorder may be self-reported. The patient may have come to resent the amount of time wasted by the compulsions; or he or she may have taken a screening questionnaire such as the brief screener available on the NIMH website (listed in the Resources section below).

The diagnosis of OCD may be complicated because of the number of other conditions that resemble it. For example, major depression may be associated with self-perceptions of being guilty, bad, or worthless that are excessive and unreasonable. Similarly, eating disorders often include bizarre thoughts about size and weight, ritualized eating habits, or the hoarding of food. Delusional disorders may entail unusual beliefs or behaviors, as do such other mental disorders as trichotillomania, hypochondriasis , the paraphilias , and substance use disorders. Thus, accurate diagnosis of OCD depends on the careful analysis of many variables to determine whether the apparent obsessions and compulsions might be better accounted for by some other disorder, or to the direct effects of a substance or a medical condition.

In addition, OCD may coexist with other mental disorders, most commonly depression. It has been estimated that about 34% of patients diagnosed with OCD are depressed at the time of diagnosis, and that 65% will develop depression at some point in their lives.

Colored positron emission tomography scans (PET scans) of a human brain, showing active areas in obsessive-compulsive disorder. In this patient, some parts of the brain show increased activity as the symptoms strengthen (areas shown in the top row), while other brain areas show decreased activity as symptoms strengthen (bottom row). (Wellcome Dept of Cognitive Neurology. Photo Researchers, Inc./ Science Photo Library. Reproduced by permission.) See color insert for color version of photo.
Colored positron emission tomography scans (PET scans) of a human brain, showing active areas in obsessive-compulsive disorder. In this patient, some parts of the brain show increased activity as the symptoms strengthen (areas shown in the top row), while other brain areas show decreased activity as symptoms strengthen (bottom row).
(Wellcome Dept of Cognitive Neurology. Photo Researchers, Inc./ Science Photo Library. Reproduced by permission.)
See color insert for color version of photo.


As of 2002, a combination of behavioral therapy and medications appears to be the most effective treatment for OCD. The goal of treatment is to reduce the frequency and severity of the obsessions and compulsions so that the patient can work more efficiently and have more time for social activities. Few OCD patients become completely symptom-free, but most benefit considerably from treatment.


Behavioral treatments using the technique of exposure and response prevention are particularly effective in treating OCD. In this form of therapy, the patient and therapist draw up a list, or hierarchy, of the patient's obsessive and compulsive symptoms. The symptoms are arranged in order from least to most upsetting. The patient is then systematically exposed to the anxiety-producing thoughts or behaviors, beginning with the least upsetting. The patient is asked to endure the feared event or image without engaging in the compulsion normally used to lower anxiety. For example, a person with a contamination obsession might be asked to touch a series of increasingly dirty objects without washing their hands. In this way, the patient learns to tolerate the feared object, reducing both worrisome obsessions and anxiety-reducing compulsions. About 75%–80% of patients respond well to exposure and response prevention, with very significant reductions in symptoms.

Other types of psychotherapy have met with mixed results. Psychodynamic psychotherapy is helpful to some patients who are concerned about the relationships between their upbringing and the specific features of their OCD symptoms. Cognitive-behavioral psychotherapy may be valuable in helping the patient to become more comfortable with the prospect of exposure and prevention treatments, as well as helping to identify the role that the patient's particular symptoms may play in his or her own life and what effects family members may have on the maintenance and continuation of OCD symptoms. Cognitive-behavioral psychotherapy is not intended to replace exposure and response prevention, but may be a helpful addition to it.


The most useful medications for the treatment of OCD are the selective serotonin reuptake inhibitors (SSRIs), which affect the body's reabsorption of serotonin, a chemical in the brain that helps to transmit nerve impulses across the very small gaps between nerve cells. These drugs, specifically clomipramine (Anafranil), fluoxetine (Prozac), fluvoxamine (Luvox), sertraline (Zoloft), and paroxetine (Paxil) have been found to relieve OCD symptoms in over half of the patients studied. It is not always possible for the doctor to predict which of the SSRIs will work best for a specific patient. Lack of response to one SSRI does not mean that other drugs within the same family will not work. Treatment of OCD often proceeds slowly, with various medications being tried before the most effective one is found. While studies report that about half of those treated with SSRIs show definite improvement, relapse rates may be as high as 90% when medications are discontinued.

Other mainstream approaches

Some treatments that have been used for OCD include electroconvulsive therapy (ECT) and, as a technique of last resort, psychosurgery for truly intractable OCD. Some patients have benefited from ECT; however, the National Institute of Mental Health (NIMH) recommends reserving ECT for OCD patients who have not responded to psychotherapy or medication.


While most patients with OCD benefit from a combination of medications and psychotherapy, the disorder is usually a lifelong condition. In addition, the presence of personality disorders or additional mental disorders is associated with less favorable results from treatment. The total elimination of OCD symptoms is very rare, even with extended treatment.

The onset of OCD in childhood is the single strongest predictor of a poor prognosis. Treatment in children is also complicated by the fact that children may find the response and exposure techniques very stressful. It is also hard for children to understand the potential value of such treatments; however, creative therapists have learned to use anxiety reduction strategies, education, and behavioral rewards to help their young patients with the treatment tasks. Concern about the long-term use of medications in children with OCD has further encouraged the use of cognitive-behavioral techniques whenever possible.

See also: Exposure treatment ; Tic disorders



Kay, Jerald, M.D., and Allan Tasman, M.D. eds. "Obsessive-Compulsive Disorder." In Psychiatry:Behavioral Science and Clincial Essentials. Philadelphia: W.B. Saunders Company, 2000.

Millon, Theodore, M.D. Personality-Guided Therapy. New York:Wiley and Sons,1999.

Pato, Michele T., and others. " Obsessive-Compulsive Disorder." In Psychiatry Volume 2. Philadelphia: W.B. Saunders Company, 1997.

Piacentini, John, Ph.D., and Lindsey Bergman, Ph.D. "Anxiety Disorders in Children." In Kaplan and Sadock's Comprehensive Textbook of Psychiatry. Volume II. Edited by Benjamin Sadock, M.D. and Virginia Sadock, M.D. Philadelphia: Lippincott, Williams and Wilkins, 2000.

Sadock, Benjamin, M.D. and Sadock, Virginia, M.D. eds. Kaplan and Sadock's Comprehensive Textbook of Psychiatry. Volume I. 7th edition. Philadelphia: Lippincott, Williams, and Wilkins, 2000.


Abramowitz, J. S. "Effectiveness of Psychological and Pharmacological Treatments for Obsessive-Compulsive Disorder: A Quantitative Review." Journal of Consulting and Clinical Psychology 65 (1997): 44-52.

McLean, Peter D. and others. "Cognitive Versus Behavioral Therapy in the Group Treatment of Obsessive-Compulsive Disorder." Journal of Consulting and Clinical Psychology 69, no.2 (2001): 205-214.


Anxiety Disorders Association of America (ADAA). 11900 Parklawn Drive, Suite 100, Rockville, MD 20852-2624.(301) 231-9350. <www.adaa.org> .

Freedom From Fear. 308 Seaview Avenue, Staten Island, NY 10305 (718) 351-1717. <www.freedomfromfear.com> .

Obsessive-Compulsive Foundation, Inc. 337 Notch Hill Road, North Branford, CT 06471. (203) 315-2196. <www.ocfoundation.org> .


National Institute of Mental Health (NIMH). Obsessive-Compulsive Disorder, 3rd revised edition, 1999. NIH Publication No. 99-3755. <www.nimh.nih.gov/publicat/ocd.cfm> .

National Institute of Mental Health (NIMH). A Screening Test for Obsessive-Compulsive Disorder. <www.nimh.nih.gov/publicat/ocdtrt1.htm.> .

Jane A. Fitzgerald, Ph.D.

User Contributions:

People deliberately pursue their rituals of doing things in order to avoid doing something else that they fear to do or wish to avoid. OCD, as something that controls you, doesn't exist! In order to get rid of OCD, focus on finding and confronting what it is that you are wanting to avoid and the OCD will disappear.
Very good comment by Stephen. I think the cause is that really something else is wrong and the obsession/compulsion, for example, somatic, is merely a sign that something else is wrong.
For me, the OCD didn't develop until I was 14 after a traumatic sexual experience causing great terror and fear mainly because I didn't know the truth about sexuality. I never had the OCD prior to that experience. I thought I was pregnant and that terrified me at that young age. The OCD started within a couple days after. It became an agonizing germ phobia which lead into other obsessions affecting every area of my life. So there must have been a drastic change in my neurochemistry propelled by the guilt and fear in the trauma. Some stories I have read seems to indicate that the OCD starts after some trauma or major change in a person's life that affects the emotions and mind. The root has to be dealt with too; where it started in order for the person to be able to work productively on the behaviors and thoughts.

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