M60. Examining the Role of Cultural Distance and Psychosocial Disempowerment in Higher Rates of Psychotic Disorders in Ethnic Minority Groups: A Multi-National Case-Control Study

Background: Ethnic minorities have an increased risk of developing psychotic disorders, but the causes remain largely unknown. Theories such as social defeat have been suggested as possible explanatory frameworks, but empirical evidence is lacking. Here, we investigated whether psychosocial disempowerment (a perceived lack of control over one’s life), and cultural distance from the majority ethnic group accounted for the excess psychosis risk in ethnic minority groups. Methods: We used case-control data from the EU-GEI study, a 16-centre case-control study in 6 countries (England, France, the Netherlands, Italy, Spain and Brazil). Within defined epidemiological catchment areas, incidence cases with an OPCRIT-confirmed first episode of ICD-10 psychotic disorder (F10-33) were invited to participate. Population-based controls were sampled via primary care. We created a binary measure of psychosocial disempowerment, using a self-perceived discrimination questionnaire, where participants were asked if they had ever felt unfairly treated in 12 situations. We approximated cultural distance using the linguistic distance of a participant’s primary language from the majority language in each setting, informed by linguistic decision trees. Age and sex were included as confounders. Following multiple imputation to account for missing data we used logistic regression to investigate whether our exposures explained any increased psychosis risk in ethnic minority groups. Results: We recruited 1168 cases and 1498 controls, who were representative of the population at-risk. Ethnic minority status was associated with increased odds of psychotic disorder after controlling for age and sex (OR: 1.66; 95% CI: 1.59–1.73). Inclusion of psychosocial disempowerment and cultural distance in the model did not attenuate risk in ethnic minority groups (OR: 1.63; 95% CI: 1.54–1.72), despite greater exposure to psychosocial disempowerment (OR: 1.54; 95% CI: 1.47–1.62) and cultural distance (OR: 3.99; 95% CI: 3.83–4.17). Both psychosocial disempowerment (OR: 1.16; 95% CI: 1.13–1.19) and cultural distance (OR: 1.17; 95% CI: 1.14–1.22) independently predicted psychosis risk, after control for age, sex and minority status. Conclusion: Ethnic minorities had a higher risk of developing a psychotic disorder. Psychosocial disempowerment and cultural distance did not explain this risk, but had independent additional effects which appeared to follow dose-response relationships. These preliminary analyses suggest the social environment of ethnic minorities might be a significant predictor of psychosis risk, independent of ethnic minority status.