The World Health Organization Composite International Diagnostic Interview (CIDI) is a structured interview for psychiatric disorders. As the interview is designed for epidemiological studies, it can be administered by those who are not clinically trained and can be completed in a short amount of time. Versions of the CIDI were used in two important studies, the National Comorbidity Survey (NCS) and National Comorbidity Survey Replication (NCS-R) which are often used as a reference for estimates of the rates of psychiatric illness in the USA. The first version of the CIDI was published in 1988, and has been periodically updated to reflect the changing diagnostic criteria of DSM and ICD. Source: Wikipedia (en)