Electronic cigarette use and mental health: A Canadian population-based study.

BACKGROUND: To examine the association between electronic cigarette (e-cigarette) use and adverse mental health status. METHODS: A cross-sectional analysis was conducted using data from the 2015 and 2016 Canadian Community Health Survey (n = 53,050). Sampling weights and associated bootstrap procedures were used to account for survey design effects. Multivariable logistic regression was employed to examine the association between e-cigarette use and the following mental health outcomes: depressive symptom ratings (using the Patient Health Questionnaire 9), self-reported professionally diagnosed mood and anxiety disorders, perceived mental health, suicidal thoughts/attempts, and binge drinking. RESULTS: The overall prevalence of past 30-day e-cigarette use was 2.9% (95% CI: 2.6-3.1). 11.5% (95% CI: 10.4-12.7) of smokers reported also using e-cigarettes. Dual users had the highest prevalence of adverse mental health status. The association between e-cigarette use and mental health was found to be modified by smoking status and sex in most of the logistic models. E-cigarettes had less than multiplicative effects among smokers. Female e-cigarette users tended to have higher odds of adverse mental health than male users. Overall, in the multivariable modeling, e-cigarette use was consistently associated with poor mental health among non-smokers and women, a finding that persisted after adjustment for additional covariates. CONCLUSIONS: These results indicate that e-cigarette use is associated with adverse mental health status, particularly among the non-smoking general population and women. LIMITATIONS: The study relied on respondent self-report, and the cross-sectional nature of the study does not allow us to clarify the direction of this association.