Association Between Second-hand Smoke Exposure and Depressive Symptoms Among Japanese Adults: A Cross-sectional Study.

BACKGROUND: Second-hand smoke exposure has been associated with poor mental health. However, among Japanese adults, little is known about the association between second-hand smoking and depressive symptoms. We examined this association in a cross-sectional study among a Japanese general adult population sample. METHODS: Japanese adults were recruited from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2012 and 2017. Second-hand smoke exposure and smoking status were assessed using a self-administered questionnaire. Based on their frequency of exposure to second-hand smoke, non-smokers and smokers were categorized as "almost never," "sometimes," and "almost every day". Depressive symptoms were defined by a Kessler 6 score ≥5 points. We performed a multivariable Poisson regression analysis to obtain adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for depressive symptoms. RESULTS: Overall, 5,121 participants (4,547 non-smokers and 574 smokers) were included whose mean age was 63.6 (standard deviation [SD], 10.3) years for non-smokers and 59.33 (SD, 10.2) years for smokers. The association between second-hand smoking and depressive symptoms was significant among non-smokers, but not among smokers. Among non-smokers, PRs compared with "almost never" were 1.25 (95% CI, 1.09-1.42) for "sometimes" and 1.41 (95% CI, 1.09-1.84) for "almost every day" (P for trend <0.001); among smokers, PRs compared with "almost never" were 1.30 (95% CI, 0.82-2.06) for "sometimes" and 1.44 (95% CI, 0.90-2.33) for "almost every day" (P for trend = 0.144). CONCLUSIONS: Second-hand smoking and depressive symptoms were associated among non-smokers. Our findings indicate the importance of tobacco smoke control for mental health.

The Association between Family Caregiver Burden and Subjective Well-Being and the Moderating Effect of Social Participation among Japanese Adults: A Cross-Sectional Study.

We examined the association between family caregiver burden and subjective well-being with social participation's moderating effect among Japanese adults. Data were obtained from a cross-sectional survey by the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2013 and 2017. Study participants included 5321 adults who visited the Public Health Center for annual health check-ups and answered a questionnaire regarding health status and lifestyle. Subjective well-being was assessed by a single item, out of 10 points, and analyzed with multivariable linear regression analysis models by subjective family caregiver burden ("none", "mild", "severe"), stratified by gender. Ultimately, 2857 men and 2223 women were included. Mean participant age (standard deviation) in years was 64.7 (10.4) for men and 61.3 (10.0) for women. Multivariable analysis revealed that, among women, higher caregiver burden was inversely associated with subjective well-being (p for trend < 0.001), and the interaction of severe caregiver burden and social participation on subjective well-being was positive and significant (p for interaction < 0.05). High family caregiver burden was inversely associated with subjective well-being among Japanese women, but moderated by the caregiver's social participation, suggesting the importance of community development that enables family caregivers' social participation to protect their subjective well-being.