Obsessive Compulsive Disorder

Obsessive compulsive disorder, or OCD, is a common anxiety disorder.

Obsessions are intrusive thoughts that seem to "hook" the mind, making it difficult to think of anything else. For some people the obsessions are simply inflations of real-world dangers (such as germs, thieves, or housefires). For others, the thoughts are about things the person might do despite not having any desire to do them: unwelcome or nonsensical violent or sexual thoughts may be involved, for example.

Some people have thoughts or images that they worry may come true if they do not stop or reverse the thought (for example, thoughts about the illness of a loved one). Still others have thoughts that have no obviously unpleasant content at all (for example, thinking of certain colours or numbers).

Obsessions are often triggered by external events or features. Leaving one’s home might bring up concerns about housefires. Using public washrooms might bring up thoughts about germs or infection. Sometimes simple colours, words, or numbers will trigger the thoughts. Once triggered, the thoughts are often followed by an intense desire to "undo" the negative feelings they cause.

Compulsions are behaviours designed to undo or "unhook" the mind from the obsession. A person might check a lock over and over, clean counters to avoid bacteria, or repeat messages to be sure they have been understood by others. A person who worries about missing important information might become reluctant to throw away newspapers.

Sometimes compulsions seem nonsensical, even to the person carrying them out. Counting backwards, avoiding sidewalk cracks, or engaging in other superstitious behaviour briefly helps the person deal with the anxiety. The relief they feel creates a positive association between experiencing the obsession and completing the compulsion. This would be fine, except that as a result the obsessions often become more frequent and the compulsions become more elaborate over time.

Some people experience obsessions but no compulsions. Others experience compulsions but are unaware of any corresponding obsessions.


Cognitive behavioural treatment of OCD can be remarkably helpful.

Cognitive work is designed to investigate the logic of the obsessions and compulsions. The person may discover half-hidden distorted ideas that serve to maintain the problem (for example, “If I think of something it will come true” or “Someday I really will read all of these newspapers from cover to cover”). When we look clearly at these thoughts, we can often realize that our reasoning does not fully hold up.

Behavioural work involves exposure to obsession triggers without engaging in "undoing" behaviours or rituals. For example, a person who tidies magazines for an hour each day might carefully choose one to leave askew. Exercises are chosen to be tolerable and easily completed.

Once successful, the person develops the confidence to attempt more difficult exposures. In this way, lengthy and elaborate compulsions can be gradually dismantled bit by bit. In the process, the anxiety tends to fade and obsessions become less frequent.

Therapy for OCD must be tightly structured and carefully carried out to maximize improvement. Most individuals are able to achieve significant gains over the problem, and learn valuable techniques for continued practice once therapy is over.

Note: Information on these pages is provided for educational purposes only. It should not be taken as a substitute for care from a qualified healthcare provider.