Obsessive-compulsive neurosis, anancastic symptomatology and ABO blood types.

Determinations of ABO blood types was carried out in 38 patients with obsessive-compulsive neurosis, 48 schizophrenics with anancastic symptomatology, 31 depressives with anancastic symptomatology, 260 schizophrenics free of anancastic symptomatology and 65 depressives free of anancastic symptomatology. Results were compared with a representative sample of the general population. The findings of the present study provide evidence of an association between obsessive-compulsive neurosis and phenotype A, whilst a similar association between ABO blood types and anancastic symptomatology occurring in the course of psychotic disorders was not found. The significance of these findings is discussed with regard to current diagnostic and aetiological issues in obsessive-compulsive neurosis.