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strain of occupying multiple roles (i.e., being a wife, mother, worker, and homemaker concurrently)23). Another study reported that employees who were taking care of Japanese elderly relatives were significantly associated with an increased risk of depression24). The study also investigated the asso-ciation between work-related stress, caregiver role, and depressive symptoms using K10, the 10- question self-rating scale developed by Kessler in the US to screen for severe psychological distress (SPD). The proportion of respondents with a high K10 score was significantly higher in women than in men. Women cope with multiple tasks, including housework, care for the elderly, and childcare duties at home, in addition to jobs outside the home; therefore, women are subjected to increased stress from various sources24). Combining these results with previous studies may give some insight into the potential significance of our findings of the gender-specific sources of stress associated with smoking behavior. Furthermore, our study showed that worry and stress emanating from interpersonal relationships were associated with a higher prevalence of smoking behavior in women. Additionally, women were more likely to suffer from multiple sources of stress in the present study. By contrast, men were not subjected to certain stressors pertaining to interpersonal relationships. As mentioned previ-ously, the traditional social role of men in Japan is to work20), and as such men often prioritize their efforts towards their jobs. On the other hand, women are traditionally expected to multitask and cope with not only their jobs but also the house-work, care of the elderly, and childcare duties. Our data suggested that given these differences in soci-etal expectations and increased caretaking demands, women were more likely to suffer stress brought on by their various interpersonal relationships.StrengthsIn this study, we used the anonymous data derived from the CSLC, covering approximately 290 thousand households and household members (approximately 750 thousand persons) who were randomly sampled. The strength of the present study is that it is the first to use a large national dataset of 20-79 years-old adults, representative of the population in Japan, to provide results on the association of the prevalence of smoking behavior with not only the experience of stress, but also the different sources of stress. This study also provides insights into gender-specific differences in sensi-bility towards worry and stress.LimitationsOur study has several limitations. First, because the study design was cross-sectional, we could not determine any causal relationship between smoking behavior and stressors. Second, people responded to the questionnaire according to their personal view of their own levels of stress rather than an objective measure. Individuals might have had different definitions of what constituted “a lot of stress,” and their responses to a stressful event might also have varied. Third, while income level would likely be related to both smoking behavior and stressors, we could not consider income level as a variable because the data were unavailable. Fourth, we categorized “smoking occasionally” or “smoking before but have not smoked for more than 1 month” as “non-smokers” since the frequency of smoking was not asked in this survey and this might result in either an underestimate or an over-estimate of the true association. Fifth, we excluded non-respondents from the present study. However, people with severe SPD or heavy smokers were considered to be more likely to decline to partici-pate in the survey, which might have led to a selec-tion bias. Finally, the prevalence of experiencing overall stress was higher among women than men in our present study. It could be possible that the gender difference in the prevalence of stress has influenced on our present results. However, many of previous studies have consistently revealed that women reported being more distressed than men25). There is also growing evidence suggested that women and men are stressed by different types of situations26-27). Nonetheless, further sensitivity study may need to be conducted by using population of no gender difference in prevalence of stress. ConclusionThe various sources of stress were associated with smoking behavior in a gender-specific manner. Both genders suffered from stressors related to financial issues (i.e., low family budget, debts), which correlated with smoking behaviors. Women 619