Author(s)
1 Sumeet Gill, BDS, MPH (student)
1 Shruti Kore, MBBS, MPH (student)
Affiliation(s)
1 Doctorate of Public Health Program, Department of Health Policy and Management, New York Medical College, New York, NY;
Abstract:
Exposure to secondhand smoke (SHS) presents established risks for cardiovascular and respiratory diseases, while its effects on mental health outcomes remain insufficiently researched. Prior research has often relied on binary SHS exposure measures, limiting insights into dose-response relationships. This study investigates whether higher household SHS exposure is associated with an increased risk of probable depression among U.S. adults using data from the National Health and Nutrition Examination Survey (NHANES) 2021–2023.A cross-sectional analysis was conducted among 6,707 U.S. adults aged 18 years or older. Depression status was determined using the Patient Health Questionnaire-9 (PHQ-9), with scores of 10 or higher indicating probable depression. SHS exposure was classified based on the number of household smokers: 0, 1, or 2 or more. Survey-weighted logistic regression was performed to examine associations between SHS exposure and depression, adjusting for age, sex, race/ethnicity, education level, marital status, income (Poverty-to-Income Ratio), alcohol use, lung disease, and asthma. In fully adjusted models, individuals living with two or more household smokers had significantly higher odds of probable depression (OR = 1.58, 95% CI: 1.03–2.44, p = 0.038), while a marginal association was observed for those living with one smoker (OR = 1.37, 95% CI: 0.99–1.90, p = 0.057). Higher depression odds were also found among women, unmarried individuals, and those with lung disease or asthma. Older adults and those with higher income had significantly lower odds of probable depression. A dose-response relationship was observed, highlighting the necessity of comprehensive smoke-free policies that address both physical and mental health risks. Future studies should investigate both biological mechanisms and socioeconomic factors that influence this association.