Cigarette smoking, alcohol use and depressive symptoms in Koreans: The Korean Longitudinal Study of Aging

Objectives The purpose of this study is to examine the relationship between substance use (e.g., cigarette smoking, alcohol use) and depressive symptoms in a cohort of Koreans aged 45 years and older from a large, population-based study.

Methods Using 2006 Korean Longitudinal Study of Aging(KLoSA), we estimated the prevalence of depressive synptoms and its association with cigarette smoking and alcohol use. A total of 10181 (56.4% for females; 43.6% for males) participated in this study. Depressive symptoms were measured by the CES-D 10-item scale. Alcohol use was categorized into four (0=never to 3=current heavy user) and cigarette smoking into three (0=never to 2=current user). Age, marital status, educational attainment, employment, and any disability were control variables. Since there were gender differences in cigartte smoking and alcohol use, we performed the separate analysis by gender.

Results The prevalence of depressive symptoms was 32% (37.1% for females; 25.4% for males). In multivariate logistic regression, ex-drinkers were more likely depressed than those nondrinkers (OR=1.37, 95%CI 1.08-1.74 for males; OR= 1.78, 1.23-2.57 for females). Compared to non drinkers, those males with light drink (OR=0.75, 0.63-0.90) were less likely to be depressed, while those heavy male drinkers were more likely depressed (OR=1.43, 1.07-1.91). Those current female smokers were more likely depressed than those nonsmokers (OR=2.07, 1.51-2.83).

Conclusions This study suggests that cigarette smoking was associated with depressive symptoms for females only. The relationship between depressive symptoms and alcohol consumption was U-shaped, indicating the lowest rate of depressive symptoms in light drinkers of Korean males.