A comparison of PTSD and traumatic event rates in a clinical sample of non-refugee immigrants and native-born individuals with a psychotic disorder: a case-control study

Background: Migration is a multi-stage social process linked to traumatic event exposure and a notably increased risk of psychosis. Although these conditions affect refugee and nonrefugee immigrants, prior trauma research has focused mainly on the refugee population. Objective: To compare and describe the rate and the clinical characterization of PTSD and traumatic events between non-refugee immigrants and native-born individuals with psychotic disorder. Methods: 99 immigrants and 99 native-born individuals (n = 198) with at least one psychotic episode according to DSM-5 criteria were compared on the rate of PTSD diagnosis and traumatic events, using standardized and validated trauma scales. Results: In the non-refugee immigrant group, 31% met diagnostic criteria for PTSD compared to only 7.1% in the native-born group. Total scores in childhood trauma and last year stressful events were 1.5 and 2 times higher in non-refugee immigrants, respectively. Likewise, cumulative lifetime trauma was three times higher in non-refugee immigrants. Finally, nonrefugee immigrants reported more violent and life-threatening traumatic events than native-born individuals. Conclusions: These results are relevant since they highlight that non-refugee immigrants with psychotic disorders are highly trauma-exposed, meaning a routine trauma assessment and a trauma-focused intervention for this population should be included in individualized treatment plans.