MARIJUANA USE BY TOBACCO SMOKERS AND NONSMOKERS: WHO IS SMOKING
WHAT?

Marijuana is often mixed with tobacco when smoked, and there is
increasing evidence that its use by non-tobacco-smoking people may be
a gateway to tobacco smoking.1 Using data from the 2004 Canadian
Tobacco Use Monitoring Survey,2 we determined whether rates of
marijuana use were similar among tobacco smokers and nonsmokers 15
years and older.

Of the respondents, 9% (2.4 million) reported using marijuana in the
12 months before the survey. In relation to tobacco smoking, 5% of
those who never smoked cigarettes reported smoking marijuana in the
12-month period (Fig. 1). Those who identified themselves as current
cigarette smokers had a substantially higher rate of marijuana use
(25%). The rates among current tobacco smokers were higher than the
national average across all age groups, even in the oldest group. Of
the respondents who were former cigarette smokers, 6% reported using
marijuana; the highest rates of use in this group were among those
aged 15--24. This finding is important, since marijuana use by former
smokers may increase their risk of smoking relapse.

The survey data suggest that marijuana use may represent a
considerable future public health burden if left unchanged.

Footnotes

This article has been peer reviewed.

REFERENCES

1. Patton GC, Coffey C, Carlin JB, et al. Reverse gateways? Frequent
cannabis use as a predictor of tobacco initiation and nicotine
dependence. Addict 2005;100:1518-25.[CrossRef]

2. Canadian Tobacco Use Monitoring Survey, 2004. Ottawa: Health Canada.
Available:
www.hc-sc.gc.ca/hl-vs/tobac-tabac/research-recherche/stat/ctums-esutc/index_e.html
(accessed 2006 Apr 3).