200 patients with an ICD diagnosis of 295, 296, 297 or 298 at their first admission were rated positive or negative for a series of different diagnostic criteria for functional psychoses. Criteria with a very wide concept of affective disorder like the VRC or the DSM-III or Taylor or St. Louis are in contrast to more narrowly defined concepts in RDC or ICD. Because of these differences there is a great need for more effective validation studies based on the simultaneous application of different diagnostic criteria. This has been called the ‘polydiagnostic approach’.