Alcoholism is a complex disorder attributed to the interaction of genetic and environmental factors. There is considerable evidence to demonstrate that genetic predisposition accounts for roughly half of the risk in the development of alcohol dependence (Schuckit, 2000; Hines et al., 2005). Twin studies have shown that the concordance rates of alcoholism in monozygotic twins are higher than that of fraternal twins (Prescott and Kendler, 1999) and that genetic risk factors are the same for women and men (Heath et al., 1997; Prescott et al., 1999). Similarly, studies of children of alcoholics who were adopted at an early age and reared by non-relatives showed six fold higher rates of alcohol abuse, regardless of their postnatal environment (Sigvardsson et al., 1996). These studies underscore the existence of predisposition or risk for alcoholism.
