Association Between Personality Traits and ALDH2 Polymorphism in Japanese Male Alcoholics

Background:  Alcoholics who have developed alcoholism despite a strong negative risk factor, that is, the inactive form of aldehyde dehydrogenase-2 (ALDH2), are considered advantageous for studying predisposing factors for alcoholism. This study aimed to compare personality profiles and clinical characteristics between alcoholics with active and inactive ALDH2. Methods:  Subjects were 460 male Japanese alcoholics hospitalized in Kurihama Alcoholism Center. All patients underwent Cloninger’s Tridimensional Personality Questionnaire and semi-structured interviews 4 to 8 weeks after admission to obtain data on personalities and clinical characteristics. ALDH2 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Sixty-six patients had the inactive form of ALDH2 (ALDH2*1/2*2) and 394 had the active form (ALDH2*1/2*1). Results:  Alcoholics with inactive ALDH2 had significantly higher novelty-seeking (NS) and lower harm-avoidance (HA) scores compared with those with active ALDH2. The inactive ALDH2 group experienced delirium tremens significantly less frequently than the active ALDH2 group. Conclusions:  These results suggest that high NS and low HA scores in alcoholics with inactive ALDH2 are associated with an increased risk for developing alcoholism, despite a low enzymatic ability to eliminate toxic acetaldehyde in these subjects. A study of alcoholics with inactive ALDH2 is useful for detecting environmental or personality factors related to alcoholism.