In psychogenic (reactive) psychosis vulnerability factors related to the premorbid character may be of more importance than the life-events preceding the psychosis. In 12 out of 28 patients with clinical psychogenic psychosis this vulnerability was related to a typically orthodox Calvinistic attitude. In such an attitude there is a discrepancy between a rationalistic-dogmatic religious conviction and the subjective religious experience in which anxiety inducing feelings of existential insecurity can dominate. During the psychotic episode these patients showed a state of excessive emotional disturbance in which anxiety inducing religious experiences were typical. In the follow-up study during a period of 4-10 years, it appeared that 14 out of the 28 patients showed relapses either as psychotic episodes or as depressions which could be diagnosed as unipolar vital depressions. In 9 out of the 28 patients a family history with affective psychosis could be demonstrated. Finally, regarding the results of the follow-up study, the reliability of the originally made diagnosis psychogenic psychosis seems doubtful. In a number of these patients the diagnosis: schizo-affective psychosis appears more relevant.