Prolegomenon to the Clinical Prerequisite; Psychopharmacology and the Classification of Mental Disorders
(Volume 1)


Conceptual Development of Current Psychiatric Nosology

Thomas A. Ban and Antonio Torrez Ruiz




Basic Principles of Psychiatric Nosology

The two major disciplines which serve as the foundation for modern psychiatry are psychopathology (general psychopathology) and nosology (clinical psychopathology). The two disciplines are intrinsically linked with each other; psychopathology deals with "subjective phenomena" ("phenomenology"), such as for example "hallucinations," and "objective performances" ("performance psychology"), such as for example "amnesias," of "psychic life," whereas "nosology" deals with "disease entities," and the "classification" of "disease entities," which result from the "synthesis" (integration) of "subjective phenomena" and "objective performances" (Jaspers, 1962).

It is a common contention that a valid "psychiatric nosology" is an essential prerequisite for a meaningful interpretation of contributions from the neurosciences with possible relevance to mental illness. Such a "nosology" could play a significant role in bridging the increasingly widening gap between neuropharmacological research and its clinical psychopharmacological applications. In spite of the high expectations from a valid system of diagnostic classification, the essential prerequisites of a "psychiatric nosology" will still need to be verified by properly conducted research. Among these prerequisites the first and probably the most important is that naturally occurring categories of mental illness exist, regardless whether any of the natural psychiatric disorders have been identified (discovered). Another important prerequisite is that each naturally occurring category of mental illness represents a "dynamic totality" which cannot be restricted to and should not be studied in a given static-state of "cross-sectional psycho- pathology" without considering the permanent changes in the disease from “onset" to "outcome. “The final and third prerequisite of a valid "psychiatric nosology" is, that each psychiatric disorder is defined by a characteristic "determining structure," which, as a rule, has the dominant effect on the integration of a variety of different elements into distinct categories of disease.