Diagnostic aspects of depression.

In this review the traditional concepts of endogenous depression and modern trials of classification in operationalized diagnostic systems, especially in DSM and ICD, are critically discussed. The psychopathological and other phenomenological symptomatologies of endogenous (cyclothymic) depression within monopolar and bipolar affective psychoses and the diagnosis and differential diagnosis above all against schizophrenia, organic brain diseases and psychoreactive disorders, are described. The possibilities and limitations of operationalized classifications with regard to diagnostic reliability and validity are presented. At present state of research homogeneous groups of patients with regard to affective and other idiopathic psychoses and here depressive syndromes and episodes cannot be defined, neither with the traditional concepts nor with the up to now available operationalized diagnostic classifications. In contemporary operationalized diagnostic systems among others the psychopathological and other phenomenological criteria are not sufficiently or too vaguely defined, the different significance of the requested inclusion-criteria and the intraindividual variability with regard to single episodes and subsequent phases of the depression are too little considered. Up to now all trials failed to validate different diagnostic concepts of depression by biological markers. Clinical psychopathological diagnosis of endogenous depression according to the traditional psychiatry criteria may reach a better validity under certain conditions than diagnoses according to DSM-III-R or ICD 10. To use exclusively operationalized diagnostic systems instead of clinical diagnosis in the diagnostic practice but also in research would be too early at present. Modern diagnostic systems can complete the clinical diagnosis but not replace it.