ABSTRACT
OBJECTIVE: This study was done to investigate the genetic polymorphism of Aldehyde Dehydrogenase (ALDH) II and Tryptophan Hydroxylase (TPH) and examine effects of socio-demographic, psychological and genetic factors on the alcohol use in freshmen of a university in Korea. METHODS: ALDH II (N=534) and TPH (N=504) genotypes of 551 subjects were analyzed using polymerase chain reaction and restriction fragment length polymorphism method. The severity of alcohol drinking was assessed by average alcohol use per drinking episode and frequency of drinking per month. Characteristics of alcohol related behaviors, socio-demographic information, and motives and expectancies of drinking in the subjects, were assessed by designed questionnaires and selfreport scales. RESULTS: The frequencies of NN, ND, and DD genotype of ALDH II (N=534) were 64.0%, 30.1%, and 5.8%, while those of AA, AC, and CC genotypes of TPH (N=504) were 31.7%, 48.4%, 19.8% respectively. The distribution of ALDH II genotypes was not correlated with that of TPH genotypes. Subjects with D (-) (NN) genotype showed more average alcohol use per drinking episode (chi2 trend=29.42, p=0.001) and higher severity index of alcohol drinking (F=9.36, df=2, p=0.000) compared with those with D (+) (ND or DD) genotypes. Subjects with D (-) genotype showed higher frequency of heavy drinking behavior (chi2 trend=5.25, p=0.022) and blackout episode (chi2 trend=17.84, p=0.001). Socio-demographic, psychological, and genetic factors seemed to contribute to the severity of alcohol drinking in the subjects. CONCLUSIONS: C allele of TPH genotypes is important in determining the severity of drinking in subjects with NN genotype of ALDH II. Social motive, gender, and D allele of ALDH II genotype are contributing factors to determine the severity of drinking in total subjects. D allele of ALDH II genotypes plays an important role in determining the severity and motives of drinking, and other alcoholrelated behaviors.