Blood groups in manic-depressive illness and schizophrenia.

Abstract

The results confirm the majority of previous findings, that there is a high frequency of the A blood group in schizophrenics and a high frequency of the O blood group in manic-depressives. Although the relationship between blood group factors and major psychosis is still poorly understood, these results indicate that the ABO genotype plays a role in the predisposition to manic-depressive illness and schizophrenia.