Fact Sheet: Obsessive-Compulsive Disorder

Obsessions are spontaneous and unwanted thoughts or impulses. These are experienced by the person as abhorrent and out of character. They can become persistent. An example would be the thought of harming someone even though you would not want to do so. Obsessions usually have themes around violence, sexual acts, doubting, blasphemy, and contamination by germs, bodily fluids or dirt.

Compulsions are the responses people make to obsessions or unpleasant feelings. They are usually repetitive and follow certain rules. They are intended to reduce unpleasant feelings or prevent bad things from happening. Some compulsions are private inner responses such as counting, praying, repeating special phrases or having certain ‘safe• mental pictures. Other compulsions are overt and include behaviours such as repeated hand-washing, checking things, placing things in order or aligning objects.

Obsessions are normal and studies have shown that approximately 80 per cent of people have them. They do not mean anything about the person and they do not signal danger.

Obsessive-compulsive disorder (OCD) occurs when the individual becomes highly distressed by obsessions and/or compulsions become time consuming and difficult to stop. Such obsessions and compulsions interfere with the person’s quality of life and in more severe cases can prevent normal everyday functioning. For example, someone with contamination obsessions may have difficulty using public washrooms and using public transport, and washing rituals may consume so much time that the person is often late for work or appointments.

Different subtypes of OCD have been identified depending on the nature of the obsessions and compulsions. The extent of overt behaviours varies and some people report predominantly thoughts rather than compulsions, in these cases the problem may be one of obsessional rumination.

Intrusive and persistent negative thoughts occur in the context of other psychological disorders and it is important to be sure that the problem is not something else. For example, in generalized anxiety disorder there is excessive worry and in depression there is brooding on negative events. These negative thoughts differ from obsessions in two ways. First, they tend to be about real-life circumstances whilst obsessions tend to be about inappropriate ideas. Second, obsessional thoughts are seen as abhorrent or disgusting but a worry or depressive thought is usually not seen in this way.

In some instances persistent and repetitive thoughts are caused by taking drugs and in such circumstances the person may be suffering from a drug-induced anxiety disorder.


The recommended treatments for OCD are Behaviour Therapy (BT) or Cognitive Behaviour Therapy (CBT). Behaviour Therapy consists of gradually exposing patients to obsessions or feared contaminants in combination with reducing the practice of rituals or compulsions this form of treatment is called exposure and response prevention. When this is achieved the level of anxiety and discomfort associated with the obsession or situation gradually decreases and disappears. This can be a slow and gradual process and it is delivered in controlled way. Cognitive Behaviour Therapy (CBT) often uses this type of exposure and ritual prevention, but also examines the person’s thoughts and beliefs and aims to challenge them. These treatments appear to be broadly equivalent in their effectiveness, with approximately 50-60 per cent of patients meeting criteria for recovery. However, the criteria suggest that residual symptoms remain an issue in many cases.

Metacognitive Therapy is a newer development in CBT and changes the emphasis of traditional treatment. There is less exposure than in BT and the therapist focuses specifically on the beliefs that the patient has about the importance and meaning of obsessional thoughts and compulsions. Treatment also focuses on developing new flexible ways of experiencing obsessions that reduces their importance and the distress they cause. Recent preliminary studies support the use of MCT but controlled trials have not yet been conducted.

Drug treatments are also used to treat OCD. Some but not all of the antidepressant drugs appear to be beneficial. A particular class called Selective Serotonin Reuptake Inhibitors (SSRI’s) can be helpful for some people, but they can also cause side effects. Your doctor can advise you about the available treatment options.

MCT References

Fisher P & Wells A (2005). How effective are cognitive and behavioural treatments for obsessive-compulsive disorder? A clinical significance analysis. Behaviour Research and Therapy, 43, 1543-1558.

Fisher P & Wells A (2008). Metacognitive therapy for OCD: A case series. Journal of Behavior Therapy and experimental Psychiatry, (in press).

Fisher P & Wells (2005). Experimental modification of beliefs in obsessive-compulsive disorder: A test of the metacognitive model. Behaviour Research and Therapy, 43, 821-829.

Wells A (1997). Cognitive therapy of anxiety disorders: A practise manual and conceptual guide. Chichester UK: Wiley. (Chapter 9-treatment manual for OCD).

Wells A (2000). Emotional Disorders and Metacognition: Innovative Cognitive Therapy. Chichester, UK: Wiley.

Wells A (2008). Metacognitive Therapy for Anxiety and Depression. New York: Guilford Press.