Modern psychiatric classification in research and clinical practice.

After general "antipsychiatric" criticism and with empirical results, which demonstrated partly very low interrater reliabilities of conventional psychiatric diagnosis a new appreciation of nosological difficulties in psychiatry arose. Based on philosophical concepts of logical empiricism which had been established in philosophy at the beginning of our century the operational psychiatric diagnosis was developed. The first system, the Research Diagnostic Criteria (RDC), was used for scientifical purpose in the early seventies. Based upon this system the American Psychiatric Association (APA) introduced DSM-III in 1980, which had a very strong influence on psychiatric diagnosis and classification during the last ten years. Operational psychiatric diagnosis is demanding precise criteria for inclusion and exclusion and definite diagnostic rules. The tenth revision of the International Classification of Diseases (ICD-10) of the WHO is in preparation and will also contain an operational approach. This new instrument will be introduced from 1992 in WHO member states. As a result of a number of empirical studies an improvement of interrater reliability in psychiatric diagnosis using DSM-III, DSM-III-R and the drafts of ICD-10 as well was demonstrated. An other important innovation of modern classification systems is the multiaxial diagnosis. These approaches have a number of advantages for clinicians, for communication in health service systems as well as for epidemiological and biological psychiatric research.