Classification and course of schizo-affective psychoses. Follow-up of patients treated with lithium.

68 patients given an ICD (international classification of diseases) diagnosis of schizo-affective disorder during a hospitalization and consecutively treated in a lithium outpatient clinic were investigated. In a 'polydiagnostic approach' the overlaps and differences between different classificatory systems were assessed. A grouping of the patients according to a 'schizophrenic axial syndrome' with an emphasis on specific thought disorders showed significant differences between these groups in regard to the development of residual symptoms. Furthermore, a relationship between the absence of the schizophrenic axial syndrome and a good response to prophylactic lithium treatment was observed.