We investigated the role of biological and psychosocial risk factors in the development of psychotic disorders with regards to immigrant status. Our hypothesis was that biological risk factors are more predictive of psychosis in non-immigrants, whereas psychosocial risk factors play a bigger role in immigrants.

A retrospective audit of admissions between December 2013 and June 2014 in an Australian adult inpatient unit was conducted, focussing on patients with psychotic disorders. We analysed the association between immigrant status, and biological and psychosocial variables.

For biological risk factors, non-immigrants had significantly more family history of psychotic disorders (p = 0.021), illicit drug use (p = < 0.001) and alcohol use (p = < 0.001). For psychosocial risk factors, immigrants were more likely to have experienced a traumatic event (p = 0.022). With regards to age of index presentation, age at onset of psychotic disorder, proportion of males and dysfunctional family background, there was no significant difference.

Retrospective data in this report suggests that the development of psychotic disorders in immigrants and non-immigrants may be different.