In 2012, 43% of Canadians reported that they had used marijuana at some time in their lives, and 12% reported using it in the past year (Statistics Canada, 2013). Marijuana use was more common among males than females (Statistics Canada, 2013). People aged 18 to 24 had the highest prevalence of past-year marijuana use, and tended to use it more frequently than did people of other ages (Statistics Canada, 2013).

In Canada, as in many other countries, marijuana is the most commonly used illicit drug (Statistics Canada, 2013).

Figure ##: Estimated prevalence (proportion) of cannabis dependence by age, sex and region, 2010. (Degenhard et al, 2013)

Throughout the world the prevalence was higher in males than females, resulting in an average male:female sex ratio of 1.8 (Degenhard et al, 2013). Prevalence peaks worldwide in the 20-24 years age group at between and then steadily decreasing after that age group thereafter (Degenhard et al, 2013).

Figure ##: Pooled regional prevalence of cannabis dependence, 2010. Note. Prevalence estimates were standardised by population age and sex; AP-HI: Asia Pacific, High Income, As-C: Asia Central, AS-E: Asia East, AS-S: Asia South, A-SE: Asia Southeast, Aus: Australasia, Caribb: Caribbean, Eur-C: Europe Central, Eur-E: Europe Eastern, Eur-W: Europe Western, LA-An: Latin America, Andean, LA-C: Latin America, Central, LA-Sth: Latin America, Southern, LA-Trop: Latin America, Tropical, Nafr-ME: North Africa/Middle East, Nam-HI: North America, High Income, Oc: Oceania, SSA-C: Sub-Saharan Africa, Central, SSA-E: Sub-Saharan Africa, East, SSA-S: Sub-Saharan Africa Southern, SSA-W: Sub-Saharan Africa, West. (Degenhard et al, 2013)

Prevalence in high income regions was much higher than that in low to middle income regions and the global average (Degenhard et al, 2013). Cannabis dependence in Australasia is about 8 times higher than prevalence in Sub-Saharan Africa, West (Degenhard et al, 2013).

Figure ##: Country-level DALYs per 100,000 population for cannabis dependence, age-standardised, for 2010. Note. Low: shows countries with statistically lower DALY rates than global mean; Middle: Shows countries with DALY rates that are not statistically different to global mean; High: Shows countries with statistically higher DALY rates than global mean. (Degenhard et al, 2013)

Worldwide, DALYs are closely associated with high income countries having more effected years compared to those of low income countries (Degenhard et al, 2013). The statistical DALY rates are comparably higher than the global mean in higher income countries than lower income (Degenhard et al, 2013).

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