Change in incidence rates for psychosis in different ethnic groups in south London: findings from the Clinical Record Interactive Search-First Episode Psychosis (CRIS-FEP) study

Background A higher incidence of psychotic disorders has been consistently reported among black and other minority ethnic groups, particularly in northern Europe. It is unclear whether these rates have changed over time. Methods We identified all individuals with a first episode psychosis who presented to adult mental health services between 1 May 2010 and 30 April 2012 and who were resident in London boroughs of Lambeth and Southwark. We estimated age-and-gender standardised incidence rates overall and by ethnic group, then compared our findings to those reported in the Aetiology and Ethnicity of Schizophrenia and Other Psychoses (ae SOP) study that we carried out in the same catchment area around 10 years earlier. Results From 9109 clinical records we identified 558 patients with first episode psychosis. Compared with ae SOP, the overall incidence rates of psychotic disorder in southeast London have increased from 49.4 (95% confidence interval (CI) 43.6-55.3) to 63.1 (95% CI 57.3-69.0) per 100 000 person-years at risk. However, the overall incidence rate ratios (IRR) were reduced in some ethnic groups: for example, IRR (95% CI) for the black Caribbean group reduced from 6.7 (5.4-8.3) to 2.8 (2.1-3.6) and the 'mixed' group from 2.7 (1.8-4.2) to 1.4 (0.9-2.1). In the black African group, there was a negligible difference from 4.1 (3.2-5.3) to 3.5 (2.8-4.5). Conclusions We found that incidence rates of psychosis have increased over time, and the IRR varied by the ethnic group. Future studies are needed to investigate more changes over time and determinants of change.