AFFECTIVE-DISORDERS AND ABO BLOOD TYPES

Results of the present study provide evidence of: 1) a positive association between bipolar affective disorder and blood type O and a corresponding negative association between the former and blood type A, 2) a positive association between unipolar affective disorder and blood type O, and 3) a positive association between involutional depression and blood type A and a corresponding negative association between the former and blood types B and O. Sex does not appear to modify the ABO blood types' distribution in patients with bipolar, unipolar affective disorder, or involutional depression, and the same holds for early‐ or late‐onset of the illness in patients with bipolar or unipolar affective disorder. Findings in the present study do not support the validity of the bipolar‐unipolar distinction of affective disorders, and provide evidence in favour of the view that involutional depression is a genetically distinct nosological entity. Copyright © 1979, Wiley Blackwell. All rights reserved