Trends in smoking rates among individuals with serious psychological distress: Analysis of data from a Japanese national survey, 2007-2016.

To determine whether the downward trend in the smoking rate over time in Japan differs between individuals with and without serious psychological distress (SPD), we used nationally representative data sets from the 2007, 2010, 2013, and 2016 Comprehensive Survey of Living Conditions of Japan. SPD was defined as a score ≥ 13 on the six-item Kessler Psychological Distress Scale. We conducted multivariate logistic regression analyses including the interaction terms between SPD and survey year. A total 187,685 participants were included. The interaction terms between SPD and survey year among men were significant for 2010 and 2016 but not for 2013. Among women, the interaction terms between SPD and survey year were not significant for any year. In conclusion, we confirmed that the gap in the rate of smoking between men with SPD and those without SPD decreased from 2007 to 2016. Among women, the gap in the smoking rate between those with SPD and those without SPD remained unchanged. Our findings suggest a need for specific support strategies including pharmacological interventions, especially for women smokers with SPD. Further studies are warranted to identify factors contributing to these sex differences.