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Obsessive-Compulsive Disorder: An Information Guide Centre for Addiction
and Mental Health

What is obsessive-compulsive disorder?

What is obsessive-compulsive disorder?

From: Obsessive-compulsive disorder: An information guide ( © 2001 CAMH)

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"I obsess about causing harm to others through some unintentional act. I worry that I have hurt someone with my sloppy or ineffectual words and will cause them to become seriously unhappy. Or that I have left a cigarette burning in my house or an appliance on and that my house will explode and wipe out the whole neighbourhood. This causes me to check things more than once before I leave the house, and then to go back into the house to check again."

Obsessive-compulsive disorder (OCD) is a severe and debilitating anxiety disorder afflicting about one adult in 40, making it twice as common as schizophrenia and bipolar disorder, and the fourth most common psychiatric disorder. OCD exists throughout the world and affects men and women at an equal rate. OCD usually begins gradually. Approximately two-thirds of the people with OCD develop the disorder in adolescence or early adulthood.

The impact of OCD on a person's quality of life is strikingly high. Every aspect of a person's life can be affected, including the way a person thinks, feels and behaves. The intensity of the symptoms can range from mild to severe and the symptoms usually wax and wane over time. In severe cases, which may define up to 20 per cent of those with the diagnosis, obsessions and compulsions can occupy the entire day and result in profound disability.

People with OCD often live with the disorder for many years before it is diagnosed and treated. Fortunately, treatment is now widely available and can be very effective in lifting the burden of this demanding and devastating illness.

Everyone has bothersome worries now and again. We may worry about a problem at work or school, about money, health, relationships or a family member. People with OCD, however, can become consumed by worry. These worries are not like those that people would normally expect to have; they are not worries about real-life problems.

When worries consume someone, we call them "obsessions." Obsessions are uninvited or "intrusive" thoughts, urges or images that surface in the mind over and over again. People with OCD know their obsessions are unrealistic creations of their own minds, but they can't get rid of them, they can't control them, and they can't ignore them. They regard their obsessions as unacceptable and sometimes repugnant. To relieve the feelings of distress and anxiety, people with OCD often try to reduce their anxiety by acting out certain rituals.

Many people have rituals, or specific ways of doing things. We may read the paper when we wake up in the morning, or arrange pencils and erasers in a particular order on our desk. For people with OCD, such rituals may become "stuck," and last for hours. Even though the person performing the ritual knows it makes no sense, he or she feels compelled to enact it over and over again. When taken to this extreme, rituals are called "compulsions."

Common compulsions include excessive washing and checking, or mental rituals, such as praying, counting, or repeating words. When these activities or thoughts are performed, they help to calm the fearfulness and anxiety associated with obsessions.

People with OCD are distressed by their obsessive thoughts and compulsive behaviour. They may avoid situations that could trigger symptoms, and because they are aware that their thoughts and actions are unrealistic, they may have difficulty sharing their concerns or seeking help for their problems.

Common Obsessions

When the fears reflected in the following obsessions are experienced, they usually result in immediate anxiety. Some of the more common obsessions are:


  • fear of contamination by dirt, germs, or other diseases (for example, by shaking hands)
  • fear of own saliva, urine, feces, semen or vaginal fluids

Repeated Doubting

  • fear of not having done a specific act that could result in harm (for example, turning off the stove, hurting someone in a traffic accident or leaving a door unlocked)
  • making a mistake


  • fear that things will not be "just right" and become distressed when things are shifted or touched
  • focus on exactness and order


  • fear of having blasphemous thoughts
  • preoccupation with religious images and thoughts


  • fear of harming oneself (for example, while eating with a knife or a fork, handling sharp objects or walking near glass windows)
  • fear of harming others (for example, poisoning people's food, harming babies, pushing someone in front of a train or hurting someone's feelings)
  • fear of blurting out obscenities in public


  • forbidden or unwanted sexual thoughts, images or urges (for example, experiencing recurrent pornographic images)
  • being obsessed with sexual thoughts that involve children or incest
  • fear of being homosexual


Most people who experience obsessions engage in extreme rituals, or compulsions. Acting out these compulsions does not give them pleasure, but it can help them feel less anxious or distressed. Compulsions can be very rigid and involve elaborate steps. They are either not realistically connected with what they are meant to stop or they are extreme beyond reason. Although by no means an exhaustive list, common compulsions include:


  • washing hands too often or in a ritualized way; showering; bathing; brushing teeth; grooming a lot or having detailed toilet routines; cleaning household items or other objects
  • avoiding objects and situations considered "contaminated"


  • checking that you don't harm others or yourself; checking that nothing terrible happens; checking that you don't make mistakes


  • making sure things are just right, or are consistent with a specific rule, such as bed sheets or notes on the desk


  • collecting seemingly useless items, such as paper, magazines, towels, bottles or pieces of garbage
  • unable to throw these same things away
"Things keep coming in to my home but nothing goes out. I don't think I even know what I have because of everything being so mixed up. NO ONE has been in the apartment for years. I'm sure my landlords would throw me out if they saw the condition of my place. I often think, what if there was a fire? I don't dare light candles and I love candles. I'm fearful of meeting someone I could care about because I could never bring him here to my home and he would be as disgusted with me as I am with myself."

Diagnosing OCD

Many people have unwanted thoughts, worries, and behavioural routines. We may dwell on unpleasant thoughts, worry needlessly about our loved ones or bite our nails. An accurate diagnosis of OCD must differentiate between those behaviours and the actual psychiatric condition.

The American Psychiatric Association defines obsessive-compulsive disorder in their diagnostic reference, the DSM-IV, as follows:

The essential features of Obsessive-Compulsive Disorder are recurrent obsessions or compulsions that are severe enough to be time consuming (i.e. they take more than 1 hour a day) or cause marked distress or significant impairment. At some point during the course of the disorder, the person has recognized that the obsessions or compulsions are excessive or unreasonable [in children this feature may be absent]. (DSM-IV, 1994, p. 417)

Clinicians are skilled at using psychiatric examinations and questionnaires to determine the seriousness of the obsessions and compulsions and the extent that these symptoms cause distress and interfere in the person's day-to-day life. Before making a diagnosis of OCD, clinicians are careful to rule out or exclude the possibility that the problems are better accounted for by one of the other disorders listed below. It is important to note, though, that many of these disorders can occur at the same time as OCD.

Other Common Anxiety Disorders

  • panic disorder (panic attacks) with or without agoraphobia (fear of leaving secure places)
  • generalized anxiety disorder (excessive anxiety or worry about real-life concerns, such as finances or health)
  • social phobia (fear of embarrassment or humiliation in social situations)
  • specific phobia (fear of a particular object or situation, such as spiders or heights)
  • post-traumatic stress disorder (fear and anxiety re-experienced in flashbacks of traumatic event)
  • anxiety disorder due to a general medical condition (this possibility can be ruled out by a physician's exam)
  • substance-induced anxiety disorder (anxiety directly related to effects of a substance, such as cocaine)

Other Disorders

Obsessive-Compulsive Personality Disorder (OCPD)
The majority of people with obsessive-compulsive personality disorder (OCPD) do not have OCD, although these disorders are commonly confused. People with OCPD have personality traits reflecting extreme perfectionism, indecision, preoccupation with details and rules, and must have things their way with family, friends and colleagues. In addition, people with OCPD show excessive devotion to work and are often considered "workaholics." They are over-conscientious and show little expression of affection or enjoyment with others. People would also recognize the person with OCPD to be "stingy." While most people with OCD may report having one or maybe even two of these traits, a diagnosis of OCPD requires that the person have five of these traits and there are clear and important differences between these two diagnoses.

When people are depressed, they often ruminate about past mistakes and perceived failures. Unlike people with OCD, who experience distress and the urge to either neutralize and/or avoid recurring thoughts or images, a person who is depressed often broods over his or her depressed state to better understand its causes and consequences. Other symptoms of depression—such as loss of interest in activities, fatigue, and appetite and weight changes—are more readily distinguishable from OCD, although the two can often occur at the same time.

This involves a compulsive habit of pulling out hairs from the head. Whereas compulsions in OCD are performed to reduce distress associated with obsessions, in trichotillomania the compulsive behaviours are not aimed at neutralizing obsessions.

Tic Disorder
Tics are sudden, rapid motor movements or vocalizations. Similar to trichotillomania, tics are not preceded by obsessions and are not engaged in to reduce obsessional distress.

There is an important distinction between an obsession (associated with OCD) and a delusion (associated with disorders causing psychosis, such as schizophrenia): the person with obsessions is usually aware of the irrationality of his or her fears, whereas the person with delusions lacks this insight. Other symptoms of schizophrenia—such as auditory and visual hallucinations, and difficulties with speech—are not commonly observed in people with OCD.

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