In the Bonn Schizophrenia Study (Huber et al, Monogr. Gesamtgebiete Psychiat., vol. 21, Springer, Berlin 1979) 113 cases fulfilled the criteria for four types of schizo-affective and/or cycloid psychoses. Each of these subgroups had a significantly more favorable long-term prognosis than that of the Bonn sample as a whole. Several prognostically favorable factors found in the Bonn Study are identical to criteria used to classify schizo-affective, schizophreniform and cycloid psychoses, e.g., acute onset, endogenomorph-depressive symptoms, and psychoreactivity. In the Bonn main sample of 502 schizophrenics, 22% demonstrated complete recovery and 40% more or less noncharacteristic types of remission (pure asthenic defect); 56% were socially recovered, two thirds reaching their premorbid level and one third remaining below it. The 12 different types of course are described. There are four course type groups, the prognostically favorable (types I–III), the relatively favorable (types IV–VI), the relatively unfavorable (types VII-IX), and the unfavorable group (types X–XII), each embracing about one quarter of all schizophrenics. The long-term prognosis is dependent on factors such as primary personality, school success, precipitating factors and certain psychopathological initial symptoms and syndromes. The results support the assumption that early treatment, including that of the prodromes, improves the long-term prognosis or at least the chance of complete remission of the subgroup with peracute and acute onset. In spite of the more favorable long-term outcome of the schizo-affective psychoses the results cannot justify the nosological differentiation and classification of these and related psychoses as an independent disease entity but only as different prognostically favorable types of endogenous psychoses. In this respect it is possible to make a distinction between a nuclear group of schizophrenia and a different group with a better prognosis, variously termed schizophreniform, schizo-affective or psychogenic psychoses, which with respect to prognosis is an intermediate group.