For many years psychiatry has been devoted to nosology.This disease model conceives psychiatric conditions as discrete entities,with a particular pathophysiology and predictable relations between phenomenology,course and outcome.
This model experienced a true revival with the introduction of the dsm-iii. Its foundations however,are weak.Many of the disorders,so delineated,are of doubtful validity.This is demonstrated,taking major depression as a paradigm.The nosological way of thought,moreover, carries with it harmful side-effects,such as:proliferation of new diagnoses,magnification of comorbidity,borderproblems and neglect of the factor psychogenesis.
The question is raised of possible alternative disease models and the reaction form model is considered to be just that.This model is defined and discussed and the conclusion is reached that it fits clinical practice and biological research better than the nosological disease model. A reconstruction of psychiatric diagnosing is proposed,in such a way that it gains in sophistication and at the same time creates opportunities for comparative studies of the merits of the nosological and the reaction form model for psychiatric practice and research.