The relationship between secondhand smoking exposure and mental health among never-smoking adolescents in school: Data from the Global School-based Student Health Survey

There is no safe level of exposure to secondhand smoking. Adolescence is a stage of rapid psychological development and is highly susceptible to various factors that can cause some mental health problems. This study aims to estimate the prevalence of secondhand smoking exposure in never-smoking school adolescents and evaluate whether there is an association between secondhand smoking exposure and mental health. 70 nationally representative data sets from the Global School-based Student Health Survey, conducted between 2003 and 2017, were used to estimate the prevalence of secondhand smoking exposure and evaluate whether there is an association between secondhand smoking exposure and loneliness, sleeplessness, and suicidal ideation. Total 191, 613 no-smoking school adolescents (43.0% boys) were included in this analysis. The prevalence of secondhand smoking exposure ranged from 15.1% in Tajikistan to 79.6% in Timor-Leste. There was no difference in the prevalence of secondhand smoking exposure between boys and girls in most countries. After adjusted, secondhand smoking exposure was positively associated with loneliness (odds ratio 1.39, 95% CI 1.30–1.49), sleeplessness (odds ratio 1.37, 95% CI 1.28–1.47), and suicidal ideation (odds ratio 1.22, 95% CI 1.15–1.30) in never-smoking school adolescents in overall samples. Use of self-report measures and potentially limited generalizability. Secondhand smoking exposure remains a serious public health issue among never-smoking school adolescents and its impact on adolescent mental health cannot be ignored. Stricter and more comprehensive policies and bans on secondhand smoking should be implemented, and adolescents' mental health should receive more attention. •Global exposure rates to secondhand smoking was reassessed according GSHS data.•Secondhand smoking (SHS) exposure was positive associated with mental health.•The effects of SHS on never-smoking adolescents should be given more attention.