How clinicians think about dual disorders: Insights from a case vignette survey

Background: Dual disorders, involving co-occurring mental health and substance use conditions, present diagnostic challenges due to overlapping symptoms. Aim: To assess the diagnostic agreement of mental health professionals in evaluating dual diagnosis cases. Methods: This Cross-sectional study surveyed 73 mental health professionals using two clinical vignettes that depicted common dual disorder scenarios: psychotic symptoms co-occurring with cannabis use and depressive symptoms co-occurring with alcohol use. Participants chose a diagnosis, rated confidence (1–10), and identified influencing factors, along with alternative differentials. Results: For the first case vignette, majority (60.2%) favored schizophrenia with cannabis use over cannabis-induced psychosis, while small number endorsed other psychotic disorders. In the second case vignette, most (89.0%) clinicians preferred major depressive disorder with harmful alcohol use, rather than alcohol-induced mood disorder. Overall confidence agreement was high (average measure ICC = 0.986) despite differences in diagnosis. Conclusion: Although clinicians diagnostic reasoning varied but confidence ratings demonstrated excellent inter – rater agreement (Average ICC = 0.986).