The first purpose of the paper is to sketch the development of the concept of axial syndromes, starting with the generation of the hypotheses in Berner’s monograph on ‘The paranoiac syndrome’ published in 1965 and leading to the last formulation of the Viennese Research Criteria in 1983. The second purpose is to draw the attention on a series of empirical studies which have been undertaken in order to evaluate the classificatory validity of the concept, studies dealing with the long-term course of paranoid psychoses (both in a retrospective and a prospective design) and secondary cases of different diagnostic classes in the families of the same patients (first-degree relatives).