Depression and substance abuse and dependency in relation to current smoking status and frequency of smoking among nondaily and daily smokers.

BACKGROUND AND OBJECTIVES: Daily smoking rates are decreasing while intermittent or nondaily smoking rates are increasing. Little is known about the association of depression, alcohol abuse and dependence, and illicit drug abuse and dependence with different patterns of smoking, particularly nondaily smoking. Thus, we examined these relationships among current smokers versus nonsmokers and among those who smoke daily versus less frequently.
METHODS: We conducted a secondary analysis of 37,897 adults who participated in the 2008 National Survey on Drug Use and Health. We developed logistic regression models examining predictors of (i) current smoking and (ii) number of days smoking per month (1-10 days, 11-29 days, and ≥30 days) among current smokers, focusing on past-year major depression, alcohol abuse and dependence, and illicit drug abuse and dependence.
RESULTS: Compared to nonsmokers, current smokers more frequently reported a major depressive episode (p < .001), alcohol dependence (p < .001) and abuse (p < .001), and illicit drug dependence (p < .001) and abuse (p < .001), controlling for sociodemographics. Among current smokers, greater smoking frequency was associated with illicit drug dependence (p = .004), but lower likelihood of alcohol dependence (p = .01), alcohol abuse (p = .01), and illicit drug abuse (p = .01).
CONCLUSIONS: Although depression and substance use were associated with greater likelihood of smoking, most measures were inversely associated with frequency of smoking. Thus, it is important to examine underlying mechanisms contributing to these counterintuitive findings in order to inform intervention approaches. SCIENTIFIC SIGNIFICANCE: With increased rates of nondaily smoking, developing a greater understanding about the mental health correlates related to this pattern of smoking is critical.