In Europe people from ethnic minorities are more likely to suffer from psychosis. This is thought to be due to social rather than biological factors as the rates of schizophrenia are increased in migrants from a wide variety of countries of origin, there is no increased incidence of schizophrenia in the countries people come from and it is unlikely that people predisposed towards psychosis would be more likely to emigrate from their country of origin. A Dutch study looked into the links between ethnicity, social adversity and people's experience of auditory and visual hallucinations as recent research suggests many people may experience these without developing full-blown psychosis. The study found that Turkish women, Moroccan men, Surinamese/Antilleans, Indonesians and other non-Western immigrants were all more likely to report hallucinations whereas Western immigrants, Turkish men and Moroccan women did not differ from their Dutch counterparts. Once social adversity was taken into account some, but not all of the increased incidence of hallucinations disappeared.
Vanheusen, K. ... [et al] - Associations between ethnicity and self-reported hallucinations in a population sample of young adults in the Netherlands Psychological Medicine August 2008, 38(8), 1095-1102