Korean Journal of Biological Psychiatry

Objectives : The aim of this study is to investigate the association between secondhand smoke (SHS) exposure and depressive symptoms among Korean adults. This study also explored the mediating role of self-rated health (SRH) and perceived usual stress (PUS) in the association between depressive symptoms, suicidal ideation and SHS exposure.

Methods : Data from the Korea National Health and Nutrition Examination Surveys (KNHANES) in 2014 and 2016 was analyzed for 10539 participants aged 19 years or older. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in the logistic regression analysis with adjustment for the potential confounding factors. We also adopted the mediation analysis method by Hayes and Preacher.

Results : After adjusting for the potential confounding factors, SHS at home and at public places were associated with depressive symptoms and suicidal ideation among non-smokers. After adjusting for the potential confounding factors, SHS at home and at public places was associated with depressive symptoms and suicidal ideation among non-smokers. Meanwhile SHS at workplaces was associated with depressive symptoms among former smokers and with suicidal ideation among current smokers. There was an additive effect of SHS on depressive symptoms only among non-smokers. SRH mediated the association between SHS and depressive symptoms and suicidal ideation among non-smokers. We did not observe any significant mediating effect of SRH nor PUS on the association between SHS and depressive symptoms among former and current smokers.

Conclusions : SHS may be associated with depressive symptoms and suicidal ideation in Korean adults. Our study elucidated how SHS interacted with depressive symptoms among non-smokers through the mediation by SRH.

Keywords Secondhand smoke;Depressive symptoms;Suicidal ideation;Self-rated health;Perceived usual stress;Korea National Health and Nutrition Examination Surveys.