Background: Although the concept of obsessive-compulsive disorder (OCD) has long been established, research diagnostic criteria are relatively recent developments. This is partly because the symptoms of OCD occur in the context of other disorders and it is arguable to what extent they are relatively discrete phenomena.
Method: Review of the existing epidemiological surveys based on standardised instruments.
Results: Nine population surveys using the Diagnostic Interview Schedule have given data on OCD, with six-month prevalences ranging from 0.7 to 2.1%. The British National Survey of Psychiatric Morbidity based on the CIS-R gave a one-month prevalence of 1% in males and 1.5% in females. Community surveys show an excess of females and emphasise the early age of onset. Minor obsessional symptoms are considerably more common than OCD itself.
Conclusions: OCD is fairly rare in the general population, but causes considerable distress to those who suffer from it.