Abstract
BACKGROUND: We aimed to evaluate the potential independent and interactive associations of tobacco and alcohol use with suicide ideation, plan, and attempt among adolescents, and the role of legal purchase age restrictions among these associations. METHODS: A pooled cross-sectional analysis was conducted with data from the Global School-based Student Health Survey (GSHS) (2013-2019), the US Youth Risk Behavior Surveillance System (YRBSS) (2021), and a Chinese school-based health survey (2017). Self-reported use of tobacco and alcohol during the past 30 days, and suicide ideation, plan, and attempt during the past year, were collected from questionnaires. Country-level purchase age restrictions on tobacco and alcohol products were obtained from official government websites. RESULTS: Among the 211,022 adolescents from 58 countries, 46.7% were boys. Compared with adolescents who used neither tobacco nor alcohol, those who used both tobacco and alcohol had the highest odds of suicide ideation (boys: 2.42 [95% CI: 2.25-2.61]; girls: 3.19 [95% CI: 2.98-3.40]; P (difference) < 0.001), suicide plan (boys: 2.39 [95% CI: 2.21-2.58]; girls: 3.33 [95% CI: 3.11-3.57]; P (difference) < 0.001), and suicide attempt (boys: 3.24 [95% CI: 3.00-3.51]; girls: 4.03 [95% CI: 3.75-4.33]; P (difference) < 0.001). In countries with higher suicide plan prevalence, boys who use tobacco and who live in countries with tobacco purchase age restrictions had lower odds of suicide plan (1.86 [95% CI: 1.64-2.12]) than those who lived in countries without restrictions (2.81 [95% CI: 2.32-3.42]). Similarly, girls who use tobacco and who live in countries with legal age purchase restrictions displayed lower odds of suicide plan (2.20 [95% CI: 1.98-2.45]) compared to those who live in countries without restrictions (4.61 [95% CI: 3.65-5.83]). However, our study revealed no subgroup differences in whether countries have legal tobacco or alcohol purchase age restrictions in association with suicide ideation, plan, and attempt risk in countries with a lower prevalence of suicide behaviors. CONCLUSIONS: Tobacco and alcohol consumption are strongly associated with the risk of suicide behaviors among adolescents, particularly among girls. Country-level tobacco control strategies may have the potential to reduce risks of suicide behaviors associated with tobacco use among adolescents.