Secondhand Smoke Policy, Secondhand Smoke Exposure, and Depression Among non-Smokers

Introduction: There has been no research on the relationship among secondhand smoke policy, secondhand smoke exposure and mental health, particularly depression.

Methods: Data were obtained from the 2006 Behavioral Risk Factor Surveillance System (BRFSS) and 2005-2006 National Health and Nutrition Examination Survey (NHANES). The Patient Health Questionnaire was used to measure current depression; secondhand smoke policy at work and home was determined by self-report; secondhand smoke exposure was determined by respondent's serum cotinine level categorized as high (.2-15 ng/mL), low (above the detection limit-.2 ng/mL), or undetectable (below the detection limit). Smokers and those with serum cotinine levels > 15 ng/mL were excluded from the analysis (NHANES only). Logistic regression analyses were performed with adjustment for survey design, comorbidity, age, race/ethnicity, gender, socioeconomic status, and alcohol consumption.

Results: Persons living in homes where smoking was allowed anywhere were more likely to be depressed, odds ratio (OR) =1.85 [95% confidence interval = 1.49-1.97] as were persons working in jobs where smoking was allowed, OR = 1.80 [1.12-2.87]. We observed a significant association between high and low/moderate cotinine exposure categories relative to those with undetectable cotinine levels OR = 3.06 [1.41-6.61] and OR =1.44 [0.66-3.10], respectively.

Discussion: Persons living in homes and working in jobs with no restrictions regarding tobacco smoking in the home or workplace policy are more likely to be currently depressed. Likewise, current depression was associated with greater exposure to secondhand smoke as measured by serum cotinine.