[Diagnostic criteria and European nosology]

The elaboration of a-theoretical comprehensive classifications has become a main concern of American psychiatry. European psychiatrists are frequently reluctant to join this consensus-based endeavour. Their nosological approaches have largely been guided by the theoretical distinction between genuine mental diseases and quantitative psychic deviations: Jasper' warning that the dismemberment of the latter leads astray incited them to concentrate mainly on the classification of the former. Thus, European psychiatrists developed several concepts of functional psychoses which differ in regard to the subdivision of these disorders and their delimitation from mere quantitative deviations. The American classifications have partially abandoned or distorted traditional european views. In order to examine the reliance of their concepts the European schools should more systematically provide operational diagnostic criteria and submit them to polydiagnostic validation-studies.