The World Health Organisation 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) [1] and National Comorbidity Survey Replication (NCS-R) [2] 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 [3] , and has been periodically updated to reflect the changing diagnostic criteria of DSM and ICD.