Nosological comparisons of alcohol and drug diagnoses: a multisite, multi-instrument international study

International nosological research was conducted to determine cross-system agreement on alcohol and drug dependence and harmful use (abuse). ICD-10, DSM-IV and DSM-III-R diagnoses were compared in 1,811 subjects from a variety of treatment and other types of settings from 12 sites around the world. Three diagnostic instruments were used: the Alcohol Use Disorders and Associated Disabilities Interview Schedule-Alcohol/Drug-Revised (AUDADIS-ADR), the composite international diagnostic interview (CIDI), and the schedules for clinical assessment in neuropsychiatry (SCAN). At seven of the study sites, two or more of these instruments were used. Results for dependence diagnoses showed excellent cross-system agreement across sites and instruments, especially for current diagnoses. Cross-system agreement for harmless use (abuse) was much lower and less consistent. Geographic location or culture appeared to have little influence on the results for either dependence or harmful use.