Overview of obsessive compulsive disorder

Obsessive compulsive disorder (OCD) is characterised by obsessions and/or compulsions. Obsessions are recurrent and persistent thoughts, impulses or images that are experienced as intrusive and unwanted. In most people, obsessions cause marked anxiety or distress. The person usually attempts to ignore or suppress these thoughts, impulses or images, or to counter them by performing a compulsion. Compulsions are repetitive behaviours (eg hand washing, checking) or mental acts (eg counting) that the person feels compelled to undertake in response to an obsession in order to prevent discomfort, or a dreaded event that the compulsion cannot realistically affect. The person usually recognises that their behaviour is excessive or unreasonable.

The obsessions or compulsions can significantly interfere with the person’s life and can impact people living or working with them.

The lifetime prevalence of OCD is 2 to 2.5%. Childhood OCD occurs in the same form as that seen in adults and usually manifests between 5 and 15 years.