Impact on routine psychiatric diagnostic practice from implementing the DSM-5 Cultural Formulation Interview: A pragmatic RCT in Sweden

Background: Culture and social context affect the expression and interpretation of symptoms of distress, raising challenges for transcultural psychiatric diagnostics. This increases the risk that mental disorders among migrants and ethnic minorities are undetected, diagnosed late or misdiagnosed. We investigated whether adding a culturally sensitive tool, the DSM-5 core Cultural Formulation Interview (CFI), to routine diagnostic procedures impacts the psychiatric diagnostic process. MethodWe compared the outcome of a diagnostic procedure that included the CFI with routine diagnostic procedures used at Swedish psychiatric clinics. New patients (n=256) admitted to a psychiatric outpatient clinic were randomized to a control (n=122) or CFI-enhanced diagnostic procedure (n=134) group. An intention-to-treat analysis was conducted and the prevalence ratio and corresponding 95% confidence intervals (CI) were calculated across arms for depressive and anxiety disorder diagnoses, multiple diagnoses, and delayed diagnosis. ResultsThe prevalence ratio (PR) of a depressive disorder diagnosis across arms was 1.21 (95% CI=0.83-1.75), 33.6% of intervention-arm participants vs. 27.9% of controls. The prevalence ratio was higher among patients whose native language was not Swedish (PR =1.61, 95% CI=0.91-2.86). The prevalence ratio of receiving multiple diagnoses was higher for the CFI group among non-native speaking patients, and lower to a statistically significant degree among native Swedish speakers (PR=.39, 95% CI=0.18-0.82). ConclusionsThe results suggest that the implementation of the DSM-5 CFI in routine psychiatric diagnostic practice may facilitate identification of symptoms of certain psychiatric disorders among non-native speaking patients in a migration context. Trial registrationISRCTN36661, 29/07/2019. The trial was retrospectively registered.