Familial rates of affective illness in Sardinia with special reference to schizoaffective disorder.

Familial rates of psychiatric disorders were studied in southern Sardinia and showed an increase in relatives of probands with the following research diagnostic criteria (RDC) diagnoses: normal, unipolar depression, schizoaffective depressive, schizoaffective bipolar, bipolar with mania and bipolar with hypomania. A significantly higher risk for bipolar schizoaffective disorder was observed in relatives of bipolar schizoaffectives compared with relatives of normal probands.