Obsessive-compulsive disorder (OCD) has similar prevalence rates across the World.1,2 Within Western countries, including the UK, the prevalence of OCD has been shown to be roughly consistent across ethnic groups. For example, the Ethnic Minority Psychiatric Illness Rates in the Community (EMPIRIC) study 3,4 examined the prevalence of mental disorders across adult British White, Black Caribbean, Indian, Pakistani, Bangladeshi and Irish ethnic groups. A similar point prevalence of OCD of around 1% was found across all ethnicities. Heyman et al 5 conducted a nationwide (UK) epidemiological survey to establish the prevalence of OCD in young people aged 5-15 (n410 000) and reported a significantly greater proportion of children from ethnic minorities among those with OCD (24%) compared with healthy controls (8.8%) and psychiatric controls (7.4%). Given the similar, if not higher, prevalence of OCD across ethnic groups in Britain [3][4][5] and elsewhere, 6 a proportional representation of different ethnic groups would be expected in mental health services. However, there is substantial evidence to indicate that patients from ethnic minorities, both children 7 and adults, 8 tend to be underrepresented in mental health services in Britain, although data specifically relating to OCD is lacking. Research conducted in North America suggests that patients with OCD from ethnic minorities are underrepresented in clinical trials. Williams et al 9 reviewed 21 randomised controlled trials of OCD conducted in North America and found that ethnic minorities were seriously underrepresented in such studies (91% of participants were White). As OCD has rarely been studied separately, there is little data relating specifically to ethnic inequalities in access to clinical services of this major, yet treatable, psychiatric disorder. The overall aim of the present study was to explore whether individuals with OCD from ethnic minorities are underrepresented in secondary and tertiary clinical services within a large mental health trust in South London, relative to the ethnic composition of the corresponding catchment area. We also aimed to determine whether ethnic inequalities, if found, are restricted to a particular age group (children v. adults) or type of clinical service (community mental health clinics v. specialist clinics) or specific to OCD (compared with depression).
Method Study settingThe South London and Maudsley (SLaM) NHS Foundation Trust is Europe's largest specialist mental healthcare trust. It serves a population of approximately 1.2 million residents of four South London boroughs: Lambeth, Southwark, Lewisham and Croydon. A proportion of SLaM services are tertiary care national referral units, 10 including three national specialist clinics for OCD: the Clinic for Young People with OCD and Related Disorders (Maudsley Hospital; child and adolescent out-and in-patients), the Centre for Anxiety Disorders and Trauma (CADAT; Maudsley Hospital, adult out-patients) and the Anxiety Disorders Residential Unit (ADRU; Bethlem Royal H...