Anxiety disorders: a comparison of the ICD-9 and DSM-III-R classification systems.

Corresponding categories for anxiety disorders, as defined by the classification systems of the ICD-9 and the DSM-III-R, were compared in a selected sample of 114 outpatients. An unequivocal category-to-category correspondence could not be demonstrated for any diagnosis. Anxiety states in ICD-9 were closely related to generalized anxiety and panic disorder in DSM-III-R, and most patients diagnosed as phobic according to ICD-9 received one of the specific phobia diagnoses of DSM-III-R. To some degree, diagnostic discrepancies were caused by coexisting symptoms of phobia, panic attacks and/or generalized anxiety within patients. A new technique is introduced to adjust corresponding proportions according to base rate differences.