Migrant groups in different regions of the world have experienced a higher risk of psychotic disorders, which is a public mental health priority. This study is to examine whether living in high own-region migrant density areas was associated with a reduced risk of psychotic disorders among migrants.

This cohort study included a total of 468,223 individuals aged 15 years or above with information regarding the date of migration until emigration or death. The primary outcome of the study was the ICD-10 diagnosis of non-affective psychosis. Factors including own-region and generation-specific own-region density were considered.

A total of 4,582 to 468,223 participants (1.0%) had non-affective psychotic disorder. After adjustment, the findings suggested that lower own-migrant density was associated with an increased risk of psychotic disorders among migrants (1.03). Further analysis indicated that psychotic effects were increasingly associated with probably visible minority migrants (1.07), notable migrants from Asia (1.42), and sub-Saharan Africa (1.28). However, this association was not evident in migrants from probable non-visible minority backgrounds (0.99).

The research concluded that migrant density was linearly associated with non-affective psychosis risk in migrants and their children. The psychotic effects were more profound in probably visible minority migrants, primarily from Asia and sub-Saharan Africa.

Ref: https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(20)30059-6/fulltext