The prevalence of non-affective psychosis in refugee populations: A systematic review

Abstract

Background: As we face the largest refugee crisis since World War Two, research is increasingly examining the impact of forced displacement. The risk of non-affective psychosis in refugees is evidenced to be significantly greater than non-refugees, and the role of pre-, peri- and post-migratory trauma and dissociation is increasingly implicated.

Aims: To determine the prevalence of non-affective psychosis in refugee populations.

Method: PRISMA guidelines were followed. Three key databases (PubMed, PsychINFO and Web of Science), Google scholar and study references were searched. The full-text of 62 studies were screened and 23 studies were eligible for inclusion. A narrative synthesis was undertaken and the Quality Assessment Tool for Quantitative Studies was used to assess methodological quality. (PROSPERO registration CRD42019152170).

Results: The results were widely heterogeneous. The combined weighted average prevalence of non-affective psychosis in refugee populations was 0.9 %. Psychosis prevalence for individual psychotic symptoms was 28.4 %; 0.5 % for schizophrenia; 1.0 % for psychosis; 0.6 % for mixed psychotic disorders and 2.9 % for psychotic episodes.

Conclusions: Variations in examined populations, diagnostic and prevalence classifications, and study designs and methodologies likely contributed to heterogeneity across the data. The findings highlight a greater need to provide more specialist mental health services and trauma-focused interventions, as well as transculturally sensitive assessment and treatment to address refugee vulnerability to psychosis. Future research should examine psychosis prevalence longitudinally and in refugees-only, address methodological bias and further examine the role of trauma and dissociation in refugee psychosis prevalence.

Keywords: Prevalence; Psychosis; Refugee; Schizophrenia; Systematic review.