Obsessive Compulsive Disorder

Obsessive compulsive disorder (OCD) is a common mental health condition that affects 2% of the population. It is characterised by obsessive thoughts that cause anxiety. This leads to rituals or repetitive actions - for example, constantly washing your hands, to relieve the anxiety.

OCD has two main features:

  • experiencing frequent, disturbing, unwanted thoughts that result in fears, and compulsions,
  • act or rituals carried out in response to fears caused by the obsessions.

The overwhelming urge to carry out a certain ritual is known as a compulsion.

Examples of compulsions include, excessive hand washing, cleaning, counting, checking, touching, arranging, hoarding, measuring, excessive neatness, and repeating tasks or actions. People with OCD carry out these types of compulsion in a desperate bid to calm the anxiety caused by their obsessions. However, once they have carried out the compulsion, they feel slightly better. This feeling is only temporary, because once the obsession comes back, the whole ritual starts again.

If the person is unable to complete the compulsion it usually results in severe anxiety or panic. This is because they think that something terrible will happen if they don't finish or don't do it properly. The thoughts and actions of OCD may become so upsetting and time-consuming that it gets in the way of work and family life. This can lead to anxiety or depression.

In some cases, a person may have only obsessive thoughts without showing compulsive behaviour or vice-versa.

Examples of obsessions are worrying excessively about germs, contamination, dirt, fearing having harmed others, intrusive sexual thoughts or urges, death and illness.

People with OCD are usually aware that their compulsions and obsessions are irrational or excessive. However, just knowing is not enough to stop the obsessions and compulsions and treatment is needed.

The following disorders also display obsessive symptoms that are similar to OCD:

  • Trichotillomania (compulsive hair-pulling).
  • Compulsive skin picking.
  • Eating disorders.
  • Body dysmorphic disorder (extreme anxiety over body appearance).
  • Hypochondriasis (irrational ideas or fears of having a serious illness).

There is also a higher rate of OCD in people with Tourette's Syndrome, affecting approximately 35-50%.


The symptoms of OCD typically begin during the teenage years or early adulthood. However, it is not unusual for children before the age of five to develop the condition. Research shows that at least one-third of cases in adults began in childhood. Only a very small minority of people develop OCD after the age of 35.

Symptoms and behaviours linked with OCD are wide-ranging. A person with OCD has either obsessions, or compulsions, or both.


are unpleasant thoughts, images or urges that keep coming into your mind. Some of the common obsessions include:

  • unwanted thoughts, often of a disturbing nature e.g. sexual or violent urges,
  • feeling the need to confess to something,
  • fear of making mistakes or behaving in an inappropriate way,
  • fear about causing harm to other people, and
  • needing everything to be perfect.


are thoughts or actions that you feel you must do or repeat. Some of the common compulsions include:

  • fear of contamination and germs, leading to constant cleaning,
  • repeatedly checking things, such as doors and locks,
  • counting, while performing routine tasks,
  • needing to do things a certain number of times or in a certain order,
  • touching or arranging items in careful and neat order,
  • hoarding objects, usually of no value, and
  • repeating numbers, words, phrases, prayers or a particular song over and over again, either under your breath or in your mind.

The physical symptoms of OCD are very similar to those of a panic attack and include:

  • sweating,
  • racing heart,
  • dizziness,
  • shortness of breath, and
  • trembling or shaking.

Social phobia and panic disorder are also more common in people with OCD.


The exact cause of OCD is unknown, but it is probably caused by a combination of factors.

OCD may be due to a lack of the brain chemical (neurotransmitter) serotonin. Low levels of serotonin are thought to be closely related to OCD.

Stress does not cause OCD. However, a stressful event or trauma seems to trigger the condition in some people.

OCD tends to run in families. Research suggests that multiple genes are involved, or it may be due to copying the OCD behaviour of another family member.

Personality type may also be a factor - for example, perfectionists seem to be more prone to developing OCD.


Those with Obsessional Compulsive Disorder (OCD) do not always get a proper diagnosis or treatment because they are worried about what others will think of them. This is particularly common in situations where the person goes to great lengths to keep their OCD secret.

Diagnosis is based on the following:

  • symptoms that cause considerable anxiety and distress,
  • symptoms that are present on most days for at least two weeks,
  • symptoms that take up more than one hour a day,
  • symptoms that significantly interfere with work, personal relationships, social activities and daily routine, and
  • the person recognises that the obsessions and compulsions are unreasonable or excessive.

If you suspect or know you have OCD, visit your GP for a diagnosis. Your GP may refer you to a psychiatrist or psychologist who is experienced in treating OCD.


Obsessive compulsive disorder and related conditions are difficult but not impossible to treat. In three out of four cases, treatment will help you gain control of the obsession and help you avoid carrying out the compulsion that usually follows.

There are two methods of treatment for OCD; drug therapy and CBT (cognitive behavioural therapy). A combination of the two therapies is often an effective method of treatment for most people.

Medication therapy

Medications that increase and maintain the serotonin levels in the brain often help to improve OCD symptoms. These are called Selective Serotonin Reuptake Inhibitors (SSRIs). In most cases, SSRIs are prescribed to restore the balance of serotonin and reduce anxiety and depression.

SSRI antidepressants include:

  • Fluoxetine
  • Sertraline
  • Paroxetine
  • Fluvoxamine

However, except for fluoxetine and sertraline, SRRIs should not be prescribed to children and adolescents under the age of 18. This is because other SSRIs have an increased risk of side effects that are not seen in adults taking the same medication.

The Medicines and Healthcare Products Regulatory Agency (MHRA) advise that fluoxetine is the preferred choice of SSRI for those under 18 years of age.

Clomipramine, a tricyclic antidepressant (TCA) used to be the usual treatment for OCD. However, TCAs have more side effects than the newer SSRIs so they are not prescribed as often.

The medicine usually takes between 2 - 4 weeks for the effects to work properly, but in some cases, it can take up to 10 weeks. Symptoms can improve by up to 70%. If the medicine is successful, it is usually taken for at least a year. The doses needed to treat OCD are sometimes higher than those needed to treat depression.

Care must be taken if the medicine is stopped as symptoms can return. However, if the medicine is combined with a course of behaviour therapy, there is less chance of the OCD returning when the medicine is stopped.

Different types of medicine affect different people in different ways, so it may take some time to find the right medicine to suit you.

Cognitive Behavioural Therapy (CBT)

CBT involves exploring the nature of anxiety and stress responses by identifying connections between thoughts, feelings and behaviour.

The therapist will gradually expose you to the feared object or idea, either directly or by imagination, and then discourage you from carrying out the usual compulsive response - for example, hand washing. The aim is for the individual to gradually experience less anxiety from the obsessive thoughts and become able to control their compulsive actions.

Some people with OCD find CBT too stressful, but the majority find it extremely helpful. CBT is not available in all areas of the UK. However, some people successfully manage their own therapy with the help and advice of support group, leaflets or books.

The information shown here is Crown copyright and has been reproduced with the permission of NHS Direct. Last updated June 2007.