Genealogic study of patients with admission diagnosis of functional psychosis.

The results are reported of a genealogic study of 313 patients (171 males and 142 females) consecutively admitted to the psychiatric department of the Medical School of Charles University in Prague, Czechoslovakia. Patients suffering from psychosis were selected and divided into five groups: "schizophrenia", "bipolar psychosis", "unipolar depressive psychosis", "schizoaffective psychosis" and "unspecified disorder" (the diagnosis of psychosis suspected but not yet certain at the time of investigation). A total of 1086 first degree relatives (parents and siblings) were ascertained and one or more first degree relatives of each proband were interviewed. The total morbidity risk of psychiatric disorder for parents and siblings was 12.6% for schizophrenic probands, 17.8% for bipolar probands, 10.7% for unipolar probands, 12.0% for schizoaffective probands and 12.6% for probands with unspecified psychosis. A striking increase of the frequency of affective disorders was found among secondary cases of schizoaffective probands. Heterogeneity between schizophrenia and primary affective disorders was tested and demonstrated. The pros and cons of the study design was discussed.