Alcohol dependence in ICD-9 and DSM-III-R: a comparative polydiagnostic study.

Diagnoses of alcohol dependence, using the classification systems ICD-9 and DSM-III-R, were compared in a sample of 215 psychiatric outpatients. A lower diagnostic threshold was obtained for DSM-III-R. This category tended to be more inclusive for relatively mild forms of inadequate alcohol use. Of those patients with ICD-9 alcohol dependence, 79% also met criteria for the corresponding DSM-III-R category, whereas 61% of subjects diagnosed as dependent according to DSM-III-R received the equivalent diagnosis in ICD-9. These results were obtained assuming equal base rates (sample frequencies) for dependence and abuse. Diagnoses were further compared with independently derived scores of the Munich Alcoholism Test (MALT), and the validity of DSM-III-R was found to be superior. Checklist-guided interviews had a positive impact upon accuracy and validity of diagnoses.