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.