Mental disorder diagnostic theory and practical reality: an evolutionary perspective.

In the current legislative debate about mandating parity of insurance coverage for mental disorders, many question the use of DSM-IV diagnostic criteria to indicate benefit eligibility. Some have indicated that resistance to adopting parity legislation has been driven by inadequacies in the theory underlying psychiatric diagnosis. This paper takes issue with that perspective and reviews the scientific basis for the current classification and the advances in research and clinical practice made possible by reliable diagnostic criteria. As hypotheses that are subject to empirical testing, the DSM-IV criteria have set the stage for further advances-independent of the economic and political forces that are now playing out in the parity debate.