Medicines for Obsessive-compulsive disorder (OCD)

What it is

Obsessive-compulsive disorder involves two linked experiences. Obsessions are intrusive, unwanted thoughts, images or urges that keep coming back and cause marked anxiety or distress — for example fears of contamination, of harm coming to others, or a need for things to feel "just right". Compulsions are repetitive behaviours or mental acts, such as washing, checking, counting or seeking reassurance, that a person feels driven to perform to relieve that anxiety or to prevent a feared outcome. The relief is usually brief, so the cycle repeats and can take up a great deal of time. OCD is common, often starts in adolescence or early adulthood, and ranges from mild to severely disabling. People frequently recognise their fears are excessive, which can add shame and delay them seeking help — but it is a recognised, treatable condition, not a character flaw.

How it is treated

The first-line treatment is a psychological therapy: cognitive behavioural therapy with exposure and response prevention (ERP), in which a person gradually faces the trigger while resisting the compulsion, so the anxiety can settle on its own and the link between obsession and ritual is weakened. For more troubling symptoms, an SSRI is the main medicine and is often combined with therapy. SSRIs in OCD are typically used at the higher end of their range and given a longer trial than in depression before judging benefit, so improvement can be gradual. Clomipramine, a tricyclic antidepressant, is an effective alternative where SSRIs have not helped or are unsuitable. Treatment is reviewed regularly, and people with severe, complex or treatment-resistant OCD should be referred to a specialist service.