Cigarette smoking and the risk for alcohol use disorders among adolescent drinkers.

BACKGROUND: Cigarette smoking and alcohol use disorders (AUDs) are closely linked, but it is not clear whether higher rates of AUD among smokers are solely attributable to heavier drinking or, alternatively, whether smokers are more vulnerable to alcohol abuse and dependence than nonsmokers who drink comparable quantities. We sought to address this issue using data from a nationally representative U.S. sample of adolescents and young adults. Specifically, we analyzed the relationship between cigarette smoking, drinking, and AUDs.
METHODS: Data were from the aggregated 2002 through 2004 U.S. National Survey on Drug Use and Health. Participants were randomly selected, household-dwelling adolescents and young adults (ages 12-20) from the noninstitutionalized, civilian population of the United States (N=74,836). Measurements included current DSM-IV alcohol abuse or dependence, number of drinks in the past 30 days, and past-year cigarette smoking, defined as having smoked more than 100 cigarettes across the lifetime and having smoked during the past year.
RESULTS: Past-year smokers (prevalence=16.0%) drank in higher quantities than never-smokers, but were also at elevated risk for AUD when compared with never-smokers who drank equivalent quantities. The effect was observed across age groups, but was more prominent among younger adolescents. After adjusting for drinking quantity and sociodemographic variables, smokers had 4.5-fold higher odds of AUD than never-smokers [95% confidence interval (95% CI), 3.1-6.6]. Youths who reported smoking but did not cross the 100-cigarette threshold were at intermediate risk [odds ratio (OR), 2.3; 95% CI, 1.7-3.3]. Differences in AUD between smokers and never-smokers were most pronounced at lower levels of drinking.
CONCLUSIONS: The results are consistent with a higher vulnerability to AUDs among smokers, compared with nonsmokers who drink equivalent quantities.