In current psychopathological research there are at least two major groups of concepts in the field of psychoses with good prognosis: the more traditional concepts of ‘bouffée délirante’, cycloid psychoses and Kasanin’s ‘schizoaffectives’ – on the other hand the modern idea of ‘concurrent schizoaffective psychoses’ like the operational criteria of Kendell, Welner, RDC, DSM-IIIR and ICD-10. Reviewing previous studies, ‘bouffée délirante’ and cycloid psychosis were found to form a homogeneous group which is very well delineated from affective and schizophrenic psychosis – to some extent also from the modern criteria of ‘concurrent