Obsessive compulsive disorder (OCD)

Also known as OCD

OCD is a condition where a person has obsessional, uncontrollable thoughts and performs compulsive and repetitive actions.

It's sometimes called a disorder of checking or doubting, as these things are both common in OCD. To have a few obsessional thoughts or minor compulsions is common. However with OCD this is far more extreme; the thoughts and actions of OCD disrupt people's lives in a most distressing way.

Main OCD myth

OCD is just being careful or fussy. NOT TRUE: OCD feels unpleasant and this myth is unhelpful to people who have it. They get no pleasure from their repeated actions and rituals.


Repetitive and unwanted thoughts, images or impulses which cause anxiety and are hard to stop. In fact, trying to stop them causes more distress. If you have OCD you know that these things come from your own mind, just like other thoughts, images and impulses, but you find them much harder to control. They are very different from the kinds of usual worries which might stay in your mind when you are focused on a particular problem.


Repeated actions or behaviour which a person feels driven to do, even though they know they are unnecessary or don't make sense. The compulsions are usually linked to the obsessional thoughts, that is, performing the compulsion temporarily relieves the anxiety and distress caused by the thoughts. For example, obsessional thoughts about your hands being dirty lead you to feel anxious about catching a disease. This leads to repeatedly and excessively washing your hands.

Some compulsions seem bizarre or silly, like touching things, counting things or putting them in exact order or symmetry. A person with OCD might hang washing out in an exact order and feel compelled to take it all down and put it up again if they think they have got the order slightly wrong. Some actions become rigid or like rituals. The person may touch things, wash their hands in an exact sequence or a particular number of times. Compulsions can also be unseen. They may include counting or praying silently, feeling compelled to think particular thoughts, or to produce particular mental images.

When people perform the compulsive action they do feel a little better initially. But then the anxiety returns and, as time passes, doing the compulsion has less effect on it. This can lead to more and more compulsive behaviour in an attempt to control the rising level of anxiety.

OCD is different from obsessional personality

It's important not to mistake OCD for a personality problem. Some people have what might be called obsessional personalities, where they are very careful and check things more thoroughly than most of us. They may be perfectionists and have very high standards in some areas. In fact it is necessary to be a bit obsessional in many jobs. We all hope that doctors or air traffic controllers will be very careful and check their work thoroughly.

Some people have particular obsessions, like never throwing anything away. Usually these tendencies do not cause great problems unless they are very noticeable, in which case they may impact on relationships with other people. Surprisingly, most people who develop OCD do not seem to have had obsessional personalities beforehand. Some people with obsessional personalities enjoy their high standards and super-clean houses. No one enjoys having OCD.


The exact cause of OCD is unknown but there is strong evidence that OCD has a physical cause in the brain. In the centre of the brain there is an area of nerve cells called the basal ganglia. This area is thought to be responsible for starting and stopping thoughts and actions and responding to new information. If this area is not working correctly it may mean, for example, that when you look to see if the door is locked this information does not register properly. Therefore, you do not stop the action of checking the locks.

The chemicals active in this part of the brain are serotonin and dopamine. Serotonin is affected by most medications that have been found to be useful in treating OCD as they increase its activity in the brain.

There is a clear genetic (inherited) factor in OCD. If you have OCD, your children have more risk than most people of getting OCD, although it is still more likely they will not develop the condition.

Cognitive-behavioural theory of OCD

Cognitive and behavioural psychology examine how we think and act. The cognitive-behavioural explanation of OCD proposes that obsessional thoughts continue because the person cannot stop or ignore them easily. This is often because they have depression which weakens their ability to distract themselves from intrusive thoughts.

Compulsions are the way a person tries to relieve the anxiety produced by obsessive thoughts, but compulsive rituals such as hand-washing after obsessive fear of contamination produce only temporary relief. Then anxiety builds up again. Every time the compulsion is repeated it gets harder to resist.

Because people learn to seek relief in this way they do not ever get the chance to learn that, in routine living, their chance of developing an infection is very small indeed. In this way, OCD is rather like an addiction. The more you do it, the more you have to do it again. OCD may be triggered by stresses which increase anxiety. Fatigue may also trigger OCD or make it worse, by making people generally more vulnerable and less able to cope.

People with OCD may believe they developed it because of stress or things that have gone wrong in their lives. Other people with OCD cannot so easily find things that have gone wrong in their lives. They may agree with the view that their mental illness is genetic or biological in origin. A lot of people with mental illness believe it is a combination of these things.

Sometimes people think their illness is a punishment for their moral or spiritual failure. It's important to remember it is not your fault you have a mental illness. Families and whanau, especially parents, can worry that they caused their relative to develop OCD. Most families and whanau want the best for their relative. It is important for them to understand what factors have contributed to their relative's problem and to be able to discuss their own feelings about this.

Who gets OCD?

About 2% of people will have significant OCD. About one-third of people with OCD will have symptoms starting in childhood, adolescence or early adult life. OCD is equally common in males and females although it usually starts later for females. Typically, OCD starts gradually and can be a minor irritation for years, eventually getting to the point where it can no longer be denied. For example: A person may deal with the obsessional thought of being dirty by washing a bit more and keeping things cleaner. Taking a shower two or three times a day might not affect anyone much. If this increases so the person spends an hour in the bathroom each morning, it becomes quite inconvenient for the household. If it increases so they spend three hours in the bathroom each day, their life has really been changed.

Five to 10 per cent of people with OCD have periods of the disorder but feel quite well in-between. Another five to 10 per cent have a more severe illness which just gets worse.


The main symptoms of OCD are the obsessions and compulsions. The content of these varies from person to person, but common themes are:

  • dirt and contamination which leads to excessive washing and avoiding possible dirt
  • doubt, leading to checking that things have been done properly - like locks being locked and stoves turned off
  • unusual or repulsive images. These may be about religion, sex, violence or suicide and may raise unrealistic fears about the safety of the person or their family or whanau.

Obsessions and compulsions are:

  • more than just excessive worries about real-life problems
  • severe enough to be time-consuming – that is, they take more than one hour a day, and cause significant distress
  • significant enough to interfere with normal daily activities and relationships.

An adult with OCD is usually aware that the obsessional thoughts or impulses are unreasonable and are a product of their own mind (as opposed to feeling that someone or something else has put them there). They usually try to ignore or suppress these thoughts, impulses or images with some other thought or action.

Related conditions

OCD is driven by the anxiety that comes with obsessions and compulsions. This anxiety can become extremely severe. Sleep is often disturbed. Depression is also very common. It may be there from the start or it may develop as the person gets worn out by the OCD. Some people become suicidal when their OCD is severe and lasts for a long time.

Anxiety and panic attacks can also occur. Addiction may become a problem if you try to reduce your OCD symptoms with alcohol or illegal drugs. Five to 10 per cent of people with OCD have sudden and involuntary movements called tics, often about the head or face. They may make sudden sounds or say or shout obscene words. Their problem may be part of another disorder called Tourette's disorder.


Treatment can greatly improve OCD but, because this is a long-term illness, treatment is often long-term too. There is a risk that people with OCD do not know they are ill and that they can be helped. Many people with OCD do not seek help until they have had the disorder for five to 10 years. The outlook without any treatment is not very good. OCD usually lasts a long time, getting worse at times when the person is stressed.

It is most important to seek help. Start by going to see your general practitioner. OCD often needs the help of a psychologist, or, in more severe cases, a psychiatrist. Do not wait till OCD has ruined your life before getting help, because treatment is very effective for almost everyone.

Credits: Mental Health Foundation of New Zealand, 2002. Reviewed By: Health Navigator, August 2014