Increase in cannabis use among Ontario adults, CAMH reports

While this CAMH Monitor eReport reveals some promising substance use trends among Ontario adults, its revelation of a substantial increase in cannabis use raises a significant public health flag.

First the more positive news. Past year smoking rates are the lowest on record, significantly declining from 28 percent in 1996 to 20 percent in 2005. Rates of drinking and driving have steadily declined from 13 percent in 1996 to just 6 percent in 2005 (the lowest on record).

These trends are hopeful, explains Dr. Jürgen Rehm, senior scientist at the Centre for Addiction and Mental Health (CAMH) and one of the study's lead investigators, but he cautions against being overly optimistic about the data. “While we are making progress, we should not forget that the prior levels of substance use in Canada were high, and we're still a long way from what is usually considered a healthy lifestyle. Also, substance use, mainly tobacco and alcohol use, still costs Canada almost $9 billion in health care costs alone each year.”

The report also shows a marked increase in cannabis use. Past year use of cannabis among Ontario adults has almost doubled since 1977, from 8 percent to 14 percent in 2005. The most salient change showed an aging of cannabis users. On average, cannabis users in 2005 were 31 years old compared to their 26-year-old counterparts in 1977. Dr. Rehm explains, however, that use is generally infrequent (less than once a month), and only 2 percent report hazardous levels of use. These data point to the need for prevention and therapy with respect to reducing the number of hazardous users and people being dependent on cannabis. Especially, the transition from infrequent or experimental use to problematic levels of use should be prevented.

Other survey data reveals that:

• The proportion of adults exceeding the recommended low-risk drinking guidelines increased between 2003 and 2005, from 21 percent to 25 percent, and
• Rates of weekly binge drinking among men and among young adults still remain at elevated levels.