Immigration, Social Environment and Onset of Psychotic Disorders

The recent decade has been characterized by a resurging interest for socio-environmental determinants of psychotic disorders, largely as a result of findings from studies of migration and psychotic disorders. This contribution reviews recent meta-analytic findings which confirm higher incidence rates of schizophrenia and related disorders among first- and second-generation immigrants than in nonimmigrant populations, as well as substantial risk variation according to both ethnic minority groups and host society contexts. The relevance of social contexts in the onset of psychosis is also suggested by incidence variation according to the neighbourhood level ethnic density. While limited, an emerging literature suggests potential variations in psychotic-like experiences and at-risk mental states according to ethnic minority status. We then discuss the meaning of findings from migrant studies, as well as integrative models that attempt to account for ethnic variations in the incidence of psychosis and psychotic-like phenomena. In conclusion, there remain numerous gaps in our understanding of the relation between migration, ethnicity, social contexts and the onset of psychosis and we propose future research avenues to address these. In particular, there is a need for multilevel approaches integrating disciplines and methodologies across the psychosis continuum.