Is secondhand smoke exposure associated with depressive symptoms among secondary school students in Malaysia? Findings from a national school-based study.

Introduction: Numerous studies have shown that secondhand smoke (SHS) is harmful to human health. Thus, the purpose of this study was to look into the relationship between exposure to SHS and depression among secondary-school students in Malaysia.

Methods: We derived the data from the Malaysian National Health and Morbidity Survey 2017: Adolescents Health Survey (NHMS 2017: AHS). We examined the association between SHS exposure and depression in 24497 secondary school students. Descriptive and multivariable logistic regression analyses were performed.

Results: The study revealed that 42% of the students were exposed to SHS during the last seven days. Depression symptoms were associated with SHS exposure (AOR=1.16; 95% CI: 1.07-1.25) after adjusting for possible confounding effects of other independent variables, including age, gender, ethnicity, smoking status of respondents, marital status of parents, physically being bullied, and physical and verbal abuse.

Conclusions: To prevent and control school-going adolescents' exposure to SHS, health education and smoking cessation among those who have close contact with adolescents should be enhanced. In addition, promoting more smoke-free areas, including houses and public places, should be intensified among secondary school students in Malaysia as they transition to adulthood.