Ethnic density as a buffer for psychotic experiences: findings from a national survey (EMPIRIC).

BACKGROUND: Aetiological mechanisms underlying ethnic density associations with psychosis remain unclear. AIMS: To assess potential mechanisms underlying the observation that minority ethnic groups experience an increased risk of psychosis when living in neighbourhoods of lower own-group density. METHOD: Multilevel analysis of nationally representative community-level data (from the Ethnic Minorities Psychiatric Illness Rates in the Community survey), which included the main minority ethnic groups living in England, and a White British group. Structured instruments assessed discrimination, chronic strains and social support. The Psychosis Screening Questionnaire ascertained psychotic experiences. RESULTS: For every ten percentage point reduction in own-group density, the relative odds of reporting psychotic experiences increased 1.07 times (95% CI 1.01-1.14, P = 0.03 (trend)) for the total minority ethnic sample. In general, people living in areas of lower own-group density experienced greater social adversity that was in turn associated with reporting psychotic experiences. CONCLUSIONS: People resident in neighbourhoods of higher own-group density experience 'buffering' effects from the social risk factors for psychosis.