The prevalence of tobacco use co-morbidities in Canada.

OBJECTIVES Tobacco use co-morbidities, including co-occurring tobacco use, substance use and mental health problems, are a serious public health issue that has implications for treatment and policy. However, not enough is known about the prevalence of various types of tobacco use co-morbidities among the Canadian population. The purpose of this study was to increase understanding of the extent of this issue through an examination of prevalence and correlates of tobacco use co-morbidities in Canada. METHODS We undertook a series of comprehensive secondary analyses of population survey data from the Canadian Community Health Survey (CCHS) and the Canadian Alcohol and Drug Monitoring Survey (CADUMS). Data were analyzed for 123,846 individuals from the CCHS and 13,581 individuals from the CADUMS. Substance use and mental health variables were compared by smoking status, with chi-square tests. Multivariate logistic regression models were fit to quantify the association between smoking, substance use and mental health issues, adjusting for age, sex, and family income. RESULTS Prevalence of problematic alcohol and illicit drug use was significantly higher among current smokers than non-smokers. Co-morbid mental health problems were also elevated among current smokers, and co-morbidities varied by age and gender. While smokers of all ages and genders were more likely to report problematic substance use and poor mental health, the effect of smoking status was significantly larger among youth. CONCLUSION Smoking in Canada is associated with problematic use of alcohol and illicit drugs, as well as co-morbid mental health problems. Youth tobacco use co-morbidities are at a concerning level, especially among young female smokers. More research on this issue in the Canadian context is needed, as well as the development of integrated interventions tailored to treat smokers with co-morbidities, particularly youth.