Distinguishing Between the Validity and Utility of Psychiatric Diagnoses

It is important to distinguish between validity and utility in considering psychiatric diagnoses. Diagnostic categories defined by their syndromes should be regarded as valid only if they have been shown to be discrete entities with natural boundaries that separate them from other disorders. Although most diagnostic concepts have not been shown to be valid in this sense, many possess high utility by virtue of the information about outcome, treatment response, and etiology that they convey. They are therefore invaluable working concepts for clinicians.