Migration is an accepted risk factor for schizophrenia but the level of risk in second-generation immigrants in unclear. A team of researchers from McGill University in Canada reviewed 21 studies into psychosis among immigrants. They found that while first-generation immigrants were 2.3x as likely to develop psychosis as other people second-generation immigrants were 2.1x as likely. While there was no significant difference in risk between the generations there were wide variations in levels of psychosis between different ethnic groups and different host countries.
Bourque, F., van der Ven, E. and Malla, A. - A meta-analysis of the risk for psychotic disorders among first- and second-generation immigrants Psychological Medicine (2011), 41: 897-910