Obsessive compulsive disorder (OCD) is one of the less common anxiety disorders but can be particularly severe and disabling. Sufferers demonstrate bizarre and repetitive behaviour, which is often distressing to themselves and those around them.

We asked Professor Paul Salkovskis of King’s College London what he would want to know about OCD.

What started my OCD?

There are points in people’s lives that have been identified as significant in the development of OCD, such as moving away from home for the first time, being promoted at work, or becoming a parent. The common factor appears to be the sense that there's an increase in responsibility.

Are my worries, and the things I do because of them, a sign that I am going mad?

People with OCD have worrying or unpleasant thoughts that keep coming back, and they do things to try and control or neutralise them. They often worry about what this might mean. For example, they worry they're losing control of their mind and could end up harming someone.

However, you're not mad, dangerous or out of control. There's a very good understanding of the thinking patterns that can lead to OCD. The psychological treatment of the disorder, cognitive behavioural therapy (CBT), is very effective and can completely resolve the problems that arise from it.

My GP suggested I go to a therapist for a course of CBT. How can I be sure it will do me any good?

Typically, when people start a course of therapy, they have known for a few years that something is wrong and have felt bad or ashamed about their disturbing thoughts, but won’t completely understand or believe what is happening or what doctors or nurses have told them. The first stage of therapy will help identify how OCD affects your life and how it gets in the way of doing the things you want to.

On average, people seek treatment 10 years after they first started having problems, and they're often depressed and have lost hope. Setting long-term goals, such as getting back into a job or rebuilding a relationship, is a good way of remembering what you're working towards. Most people suffering from OCD benefit from CBT.

I had treatment and it got rid of most of my symptoms. Is that enough?

Treating OCD is a bit like fighting an infection. It's important to deal with all the obsessional anxieties to be sure there's no risk of the condition returning. Some people, once they have regained their self-confidence, continue working on their fears after the therapy course has ended.