Personality disorders according to DSM-III-R and thrombocyte monoamine oxidase activity in type 1 and type 2 alcoholics

Objective: Several criteria used to distinguish Type 2 alcoholics from Type 1 alcoholics, as well as the incidence of lower platelet monoamine oxidase (MAO) activity in the Former group, would indicate that personality disorders might be more common in Type 2 alcoholics. The purpose of the present study was to investigate the relation between personality disorders, according to DSM-III-R, platelet MAO activity and Type 1/Type 2 alcoholism. Method: The occurrence of personality disorders, according to DSM-III-R, was studied in a series of 34 male inpatients with alcohol dependence, subclassified into Type 1 (n=18) and Type 2 (n=16). Platelet MAO activity was studied in the same series of patients. Results: Patients with Type 2 alcoholism had significantly higher frequencies of self-defeating, schizotypal, antisocial and borderline personality disorders than Type 1 alcoholics. Patients with Type 2 alcoholism had significantly lower mean activity of platelet MAO than Type 1 alcoholics. No correlation was found between platelet MAO activity and personality disorders according to DSM-III-R. Conclusions: Disorders of the antisocial personality and borderline personality types as well as low platelet MAO can all predict the occurrence of Type 2 alcoholism with rather high specificity but with a comparatively low degree of sensitivity.