The World Health Organization Composite International Diagnostic Interview (CIDI) is a fully structured diagnostic tool designed for lay interviewers to assess the prevalence of mental and substance use disorders. Earlier versions, such as the CIDI 3.0, demonstrated acceptable individual-level concordance with clinical assessments based on DSM-IV criteria (Haro et al. 2006). The latest iteration (CIDI 5.0) has been updated to operationalize DSM-5 criteria.
Recent evidence from a large-scale, community-based national study in Qatar suggests that under DSM-5 criteria (Khaled et al. 2024), after recalibration, the CIDI 5.0 maintains high specificity (91.9% for MDD, 94.7% for GAD, and 85.5% for PTSD). Sensitivity suggested CIDI diagnoses aligned closely with clinical "gold standard" diagnoses (51.5% for MDD, 50.7% for GAD, and 77.3% for PTSD). Despite the evidence from Qatar, there remains a lack of evidence regarding the validity of the CIDI 5.0 in population-based studies.
Therefore, this study aims to evaluate the diagnostic validity of the CIDI 5.0 for Lifetime MDD, GAD, and PTSD, using the Structured Clinical Interview for DSM-5 (SCID-5) as the definitive clinical gold standard.