The relationship between smokeless tobacco (snus) and anxiety and depression among adults and elderly people. A comparison to smoking in the Tromso Study

Aims To (i) define the characteristics of snus users compared with non-users and smokers and (ii) define the relationship between snus use and self-reported anxiety and depression and compare it with the relation between smoking and anxiety and depression. Design, setting and participants A cross-sectional study based on data from the Norwegian population-based survey, the Tromso Study (2015-16). A total of 32 591 people aged 40 years and older in the municipality of Tromso were invited to attend. There were 21 083 respondents, giving a 65% attendance rate. Measurements Tobacco use was assessed by current and previous use of snus or cigarettes. Symptoms of anxiety and depression were measured using the Hospital Anxiety and Depression Scale (HADS). Findings Snus users were more often male, were younger and had higher income and higher alcohol consumption than smokers and non-users of snus. In a linear regression analysis, we found no significant association between current snus use and anxiety and depression after adjusting for background variables. However, there was a positive association between previous snus use and anxiety among males [adjusted beta = 0.258; 99% confidence interval (CI) = 0.023-0.492]. Regarding anxiety, the adjusted beta-coefficients for current smoking were 0.425 (99% CI = 0.184-0.666) for females and 0.303 (99% CI = 0.084-0.522) for males. Concerning depression, the adjusted beta coefficients for current smoking were 0.569 (99% CI = 0.358-0.780) for females and 0.281 (99% CI = 0.060-0.503) for males. Conclusions In Norway, current snus users differ from current smokers by having a higher socio-economic status and no detectable association with anxiety and depression. This suggests that the relationship between tobacco use and anxiety and depression is associated with the administration method.