Association of Tobacco Use and Exposure to Secondhand Smoke With Suicide Attempts Among Adolescents: Findings From 33 Countries

Introduction: There is evidence to suggest that tobacco use is associated with suicide attempts. However, it is unclear whether such an association can be extended to include secondhand smoke exposure. Using nationally representative data of school-attending adolescents from 33 countries, we examined the association of tobacco use and exposure to secondhand smoke with suicide attempts. Methods: We used data from the Global School-based Student Health Survey, a cross-sectional survey conducted among adolescents 12-15 years of age. We used logistic regression to estimate the country-specific associations. We then conducted random effect meta-analyses to obtain overall and country-income level pooled estimates. Lastly, we used logistic regression analyses to investigate a dose-response association of cigarette smoking and exposure to secondhand smoke with suicide attempts. Results: A positive association between tobacco use and suicide attempts among adolescents was present regardless of country-income level (low income: odds ratio 4.98, 95% CI: 3.11-7.96; lower middle income: 3.47, 2.91-4.15; upper middle income: 3.09, 2.75-3.47; and high income: 3.18, 2.63-3.84) and gender (boys: 3.28, 2.86-3.76; girls: 3.86, 3.30-4.51). Exposure to secondhand smoke was associated with suicide attempts, albeit weakly, among girls only (1.26, 1.14-1.39; boys: 1.00, 0.87-1.15). There was some evidence that a dose-response association of cigarette smoking and exposure to secondhand smoke with suicide attempts may only exist among girls. Conclusions: Adolescents who use tobacco, and adolescent girls exposed to secondhand smoke were found to be more likely to attempt suicide; however, future longitudinal studies are warranted to assess causality. Implications: Our findings indicate that routine screening of adolescents for tobacco use should be implemented globally, especially when assessing suicidal behaviors and risk. Future longitudinal and intervention studies are warranted to assess causality and whether prevention efforts such as tobacco control interventions and programmes targeting tobacco use and exposure to secondhand smoke among adolescents could ultimately lead to a reduction in the occurrence of suicide attempts.