For many years both clinicians and researchers have acknowledged the strong comorbidity between smoking and alcohol dependence. This issue cannot be explained simply in terms of shared individual risk factors. Genetic approaches are likely to play an important role in helping to document the biological mechanisms underlying this association. The experimental finding that smokers appear to experience less intoxication after a challenge dose of alcohol than do nonsmokers, combined with evidence that low reactivity to alcohol predicts increased long-term risk of alcohol dependence, suggests that further experimental studies of nicotine-alcohol interactions using genetically informative approaches should be a research priority.
