Neuroses and ABO blood types.

Determination of ABO blood types was carried out in 72 (35 female and 37 male) patients with obsessive-compulsive neurosis, 73 (35 female and 38 male) patients with phobic neurosis, 75 (54 female and 21 male) patients with hysteria and a random sample of 600 individuals (268 female and 332 male) drawn from the general population. Results provide evidence of: (1) a positive association between obsessive-compulsive neurosis and blood type A and a corresponding negative association between the former and blood type O; (2) a positive association between phobic neurosis and blood type O and a corresponding negative association between the former and blood type A, and (3) a positive association between hysteria and blood type A and a corresponding negative association between the former and blood type O. Moreover, sex does not appear to modify the ABO blood type distribution in our patients with obsessive-compulsive neurosis, phobic neurosis or hysteria. These findings might be considered as supporting the view that hereditary factors in the neurotic individual may influence the clinical form of his neurosis.