Cigarette smoking has been identified as a cause of cancer incidence and mortality since the end of World War II¹ and remains a major public health problem today.^2,3 Most smokers initiate tobacco use in adolescence⁴ and attempt to quit at around 30 years of age (especially women) or after 50 years of age.⁵ Pharmacotherapies (nicotine replacement therapy [NRT], bupropion hydrochloride, and varenicline tartrate) and behavioral therapies have been shown to be effective in helping smokers quit.^6-8 However, the appeal of smoking cessation aids is relatively low,⁹ and most quit attempts are done “cold turkey” (ie, stopping nicotine consumption all at once), without professional assistance or treatment,^10-13 which may be because smoking cessation aids have a financial cost or because smokers lack knowledge about their effectiveness and safety. There are also other reasons for not using smoking cessation aids; for example, some smokers believe that quitting without help gives them greater satisfaction and a feeling of self-control, strength, and autonomy.¹⁰ However, studies show that smokers who use smoking cessation aids are more likely to remain abstinent.¹⁴

Canada is a federal state of almost 38 million inhabitants distributed over ten provinces and three territories, each with their own power regarding health. This case study describes the health infrastructures’ situation before the COVID-19 outbreak and their adaptations to face the expected cases, the available epidemiologic data for the beginning of the first wave (January–April 2020), and the public health and economic measures taken to control the pandemic both at the federal level and breaking down by province and territory. Canadian health infrastructures offered on average 12.9 intensive care units beds per 100,000 (occupancy rate ~90% before the outbreak), unevenly distributed across provinces and territories. Canada implemented public health measures, such as social distancing, when hospitalization and death rates due to the pandemic were still lower than in other countries; each province and territory adapted and implemented specific measures. Cumulated cases and deaths substantially increased from mid-March 2020, reaching 65 cases and 2 deaths per 100,000 on April 12, with strong differences across provinces and territories. Canada has been affected by the COVID-19 pandemic’s first wave with a generally slower dynamic than in the USA or in the European Union at the same period. This suggests that implementation of public health measures when health indicators were still low may have been efficient in Canada; yet the long-term care sector faced many challenges in some provinces, which drove a large part of the pandemic indicators.

To examine the cross-sectional and longitudinal associations between depressive symptoms and electronic cigarette (e-cig) use in a large population-based sample while taking into account smoking status and sociodemographic confounders. Participants from the French Constances cohort were included from February 2012 to December 2016. Smoking status, e-cig use (never/ever/current) and nicotine concentration were self-reported. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression (CES-D) scale. Logistic regressions were used to provide odds ratios (ORs) and 95% confidence intervals (95%CI) of e-cig use according to depressive symptoms, adjusting for age, sex and education. In cross-sectional analyses (n = 35,337), depressive symptoms (i.e. a CES-D score ≥ 19) were associated with both ever (OR [95%CI]: 1.67 [1.53-1.82]) and current (1.73 [1.53-1.96]) e-cig use with a dose-dependent relationship (p-trend<0.001). In longitudinal analyses (n = 30,818), depressive symptoms at baseline were associated with current e-cig use at follow-up (2.02 [1.72-2.37]) with a similar dose-dependent relationship. These associations were mainly significant among smokers or former smokers at baseline. Furthermore, among smokers at baseline, depressive symptoms were associated with dual consumption at follow-up (1.58 [1.41-1.77]), whereas among former smokers, they were associated with either smoking only (1.52 [1.34-1.73]) or e-cig use only (2.02 [1.64-2.49]), but not with dual consumption (1.11 [0.73-1.68]) at follow-up. Finally, depressive symptoms were positively associated with nicotine concentration among e-cig users at baseline. Depressive symptoms were positively associated with e-cig use in both cross-sectional and longitudinal analyses with a dose-dependent relationship. In addition, nicotine concentration and depressive symptoms were positively associated.