Migration, ethnicity, and psychoses

The incidence of psychotic disorders is increased, to varying extents, in many migrant and minority ethnic populations in several countries. This chapter briefly reviews the evidence on disparities in incidence between minority and majority populations and then discusses possible explanations. It is unlikely that methodological artifact, including misdiagnosis, can fully account for the high incidence rates observed in some populations. Further, there is no evidence that established neurodevelopmental risk factors for psychosis explain disparities among ethnic groups. It is, then, most likely—and there is growing evidence to support this—that the high rates are a consequence of greater exposure to adverse social conditions and experiences, particularly those involving threat and violence, over the life course among minority ethnic groups. In other words, psychosis occurs more often in some minority populations via a socio-developmental pathway.