The British Journal of Psychiatry 131: 478-485 (1977)
© 1977 The Royal College of Psychiatrists
Genetical analysis of unipolar and bipolar endogenous affective psychoses
O Trzebiatowska-Trzeciak
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.
