"Among those who used cannabis, 17.7% (representing about 420,000 Canadians or 1.6% of the Canadian population aged 15 years and older) reported doing so for medical purposes. Prevalence of use for medical purposes was similar between male and female cannabis users (17.3% versus 18.4%, respectively), while more than one in five (21.8%) cannabis users aged 25 years and older reported using it for medical purposes, representing 1.5% of all adults in this age group. The percentage of youth who used cannabis for medical purposes is not reportable.
"Half (49.7%) of those who used cannabis for medical purposes did so mainly for chronic pain caused by conditions such as arthritis, back pain and migraines, while the remaining 50.3% used cannabis primarily for one of a variety of conditions that included insomnia, depression and anxiety. These numbers do not in any way measure or reflect enrolment in the federal Medical Marijuana Access Program."
Canadian Alcohol and Drug Use Monitoring Survey (CADUMS) Summary of Results for 2011 (online only), last accessed Dec. 12, 2012.