Divergence and convergence of diagnoses for depression between ICD-9 and DSM-III-R

Contrasting the classification systems ICD-9 and DSM-III-R, a comparison of diagnoses for unipolar depressive disorders is presented from a sample of 168 psychiatric outpatients. A relatively clear correspondence existed between ICD-9 endogenous depression and DSM-III-R major depression. Neurotic depression (ICD-9) divided into either dysthymia or major depression in DSM-III-R. A generally greater variety of corresponding ICD-9 diagnoses was observed for DSM-III-R categories, since patients with eating disorders, alcohol or drug dependence, or with neuroses other than depressive type often received an additional specific DSM-III-R diagnosis for depression. For ICD-9 diagnostics, a decreased threshold was found for diagnosing depressive reaction, as compared with the equivalent DSM-III-R diagnosis of adjustment disorder with depressed mood. A new technique is introduced in order to adjust corresponding proportions according to base rate differences.