Alcoholism is a chronic, disabling disorder with estimated lifetime prevalence of 19% in men and 8% in women in the U.S. (Grant, 1997). The combination of heavy drinking and smoking represents the single greatest cause of preventable morbidity and mortality in Western societies (Edwards, 2004). In addition to numerous social and environmental factors, variation in susceptibility to alcohol dependence is likely influenced by inter-individual differences in pathways involved in alcohol metabolism and neurotransmission (reviewed in (Tyndale, 2003; Dick and Bierut, 2006)). The primary ethanol metabolism pathway is a two-stage process—first, oxidation to acetaldehyde, catalyzed by alcohol dehydrogenases (ADHs), followed by further oxidation to acetate, catalyzed by aldehyde dehydrogenases (ALDHs). The buildup of acetaldehyde in the blood causes the flushing reaction common in several Asian populations and generally results in lower alcohol consumption (Hurley et al., 2002).
