title: Genetical analysis of unipolar and bipolar endogenous affective psychoses.
abstract: The mode of inheritance of affective psychoses was studied in 800 first degree and 582 second degree relatives of 122 probands. Morbidity risk for unipolar depression was 12.0+/-3.2 and 11.4+/-2.7 per cent respectively for parents and siblings of probands suffering from unipolar depression. Morbidity risk for manic-depressive psychosis for the respective groups of first degree relatives of manic-depressive probands was 15.1+/-3.2 and 16.9+/-3.2 per cent. In second degree relatives the morbidity risk was 3.4+/-1.0 and 5.3+/-1.4 per cent for unipolar depression and manic-depressive psychosis respectively. The results indicate the role of genetical factors in the etiology of both types of affective disorder and show that unipolar depression and manic-depressive psychosis are distinct entities. The hypothesis of X-linked dominant transmission was not confirmed in either of these affective disorders. By means of the computational model of Slater, no results compatible with a polygenic inheritance of unipolar depression or manic-depressive psychosis were found.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D003863:Depression / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D012737:Sex Factors