The semantic status of diagnostic criteria for organic mental syndromes and disorders in DSM-III and DSM-III-R.

After a general introduction referring to the contemporary debate about psychiatric classification, the nature of so-called "diagnostic criteria" in psychiatry is discussed with special reference to DSM-III(-R) and to organic mental syndromes and disorders. A set of diagnostic criteria for a disease category can be intended alternatively (i) as stating logically necessary and/or sufficient conditions for the diagnostic concept in question, or (ii) as providing contingent (probabilistic) indicators of the disease. In one possible interpretation, a main aim of DSM-III and DSM-III-R has been to formulate type (i), logical criteria, which amounts to an attempt to strictly identify syndromes or disorders with complex (polythetic) sets of easily observable symptoms and signs. It is shown that a logical interpretation would lead to such unwanted consequences for clinical and scientific practice that it could not possibly have been intended by the authors of DSM-III and DSM-III-R. But neither can the alternative interpretation in terms of type (ii), contingent or probabilistic indicators be consistently upheld. The conclusion of the essay is that the semantic status of the diagnostic criteria in DSM-III and DSM-III-R is fundamentally blurred. This unclarity may very well lead to divergent interpretations of the concepts and to corresponding uncertainties in their clinical and scientific application.