Last month, Bill C-45, also known as the Cannabis Act, passed its second reading in the House of Commons — the culmination of several days and late nights of debate among members of Parliament about the proposed framework for legalized cannabis.
‘Perplexing’ might be a good word to describe many of the arguments made in the House. Some were obscure to the point of entertainment (just look up #toasterbud), but others were disconcerting for those of us researching cannabis and public health.
While it’s hard to resist the amusement of watching our elected representatives engage each other in a serious debate using words like “doobie” and “reefer” — and predicting that children will use toaster ovens to dry out and smoke homegrown cannabis, for every embarrassing cannabis pun or laughably far-fetched “what-if” scenario, there were just as many unchecked scientific-sounding claims about the public health impacts of cannabis policy.
But to what extent are these claims rooted in reality? MPs are not required to cite supporting sources of evidence in House debates, often preventing the public from critically analyzing the validity of their statements.
So we set out to unpack three of the most common claims heard in House of Commons about the health and social impacts of cannabis legalization in other jurisdictions — and test them against current scientific evidence.
Claim #1: Legalization has led to increased rates of cannabis use among youth in Colorado and Washington
The governing Liberal MPs have been tireless in emphasizing that youth are at the center of their plan to legalize cannabis. Noting that Canada’s youth lead the world’s richest nations in rates of cannabis use, supporters of the bill have pointed to the failings of prohibition, arguing that regulating and restricting access to cannabis will “keep it out of the hands of children”.
The opposition Conservatives have never missed an opportunity to claim that this legislation — which allows up to four cannabis plants per household and protects youth from harsh criminal penalties for simple possession of five grams or less — will encourage use among Canada’s youth. Several Conservative MPs cite Colorado and Washington as examples to demonstrate that legalization will lead to escalating youth cannabis use. But did youth usage really increase in these states after legalization?
Let’s look at Colorado. The Rocky Mountain High Intensity Trafficking Area provides annual reports for Colorado based on the National Survey of Drug Use and Health (NSDUH). Past-month use of cannabis among 12 to 17 year-olds in Colorado was estimated at 6.7 per cent in 2005/2006 before rising to 12.6 per cent in 2013/2014, ranking Colorado’s youth as the leading consumers of cannabis in the U.S. Since this increase took place over a period of time during which recreational cannabis became legal (Colorado voted to legalize cannabis in 2012, with the first state-licensed retail outlets opening in 2014), Conservative MPs charged that legalization was the driver of escalating cannabis use among youth.
However, this implication overlooks the fact that much of the increase took place before legalization. There was only a 1.4-percentage point increase following legalization, which proceeded to drop again by 1.5 percentage points in 2014/2015. Dr. Larry Wolk, Director of the Colorado Department of Public Health and Environment, has also dismissed the claim that legalization led to increased use among young people.
Data from the Healthy Kids Colorado Survey, collected biannually by the Colorado Department of Public Health and Environment and the University of Colorado, further calls this claim’s validity into question. According to the 2015 survey, 21.2 per cent of Colorado high school students reported using cannabis in the previous month — a rate that has remained relatively unchanged from 22 per cent in 2011.
Even if rates in these reports were found to have increased significantly since legalization, any population health researcher would strongly caution against making statements about causality. This is because the changes in state rates were not tested against simultaneous changes in other state rates, and other potential state-level drivers of changing cannabis use patterns were not controlled for in statistical analyses.
Recent peer-reviewed research compared Colorado and Washington rates over a five-year period to 45 states without recreational cannabis and found that cannabis use has not increased significantly among high school students in Colorado since legalization. The study did note that in Washington, rates have increased slightly yet significantly among Grade 8 and 10 students since legalization, alongside noted decreases in perceived harmfulness of cannabis among them.
Claim #2: Cannabis impaired driving and traffic fatalities have increased in Colorado and Washington since legalization
‘Perplexing’ might be a good word to describe many of the arguments made in the House. Some were obscure to the point of entertainment (just look up #toasterbud), but others were disconcerting for those of us researching cannabis and public health.
While it’s hard to resist the amusement of watching our elected representatives engage each other in a serious debate using words like “doobie” and “reefer” — and predicting that children will use toaster ovens to dry out and smoke homegrown cannabis, for every embarrassing cannabis pun or laughably far-fetched “what-if” scenario, there were just as many unchecked scientific-sounding claims about the public health impacts of cannabis policy.
But to what extent are these claims rooted in reality? MPs are not required to cite supporting sources of evidence in House debates, often preventing the public from critically analyzing the validity of their statements.
So we set out to unpack three of the most common claims heard in House of Commons about the health and social impacts of cannabis legalization in other jurisdictions — and test them against current scientific evidence.
Claim #1: Legalization has led to increased rates of cannabis use among youth in Colorado and Washington
The governing Liberal MPs have been tireless in emphasizing that youth are at the center of their plan to legalize cannabis. Noting that Canada’s youth lead the world’s richest nations in rates of cannabis use, supporters of the bill have pointed to the failings of prohibition, arguing that regulating and restricting access to cannabis will “keep it out of the hands of children”.
The opposition Conservatives have never missed an opportunity to claim that this legislation — which allows up to four cannabis plants per household and protects youth from harsh criminal penalties for simple possession of five grams or less — will encourage use among Canada’s youth. Several Conservative MPs cite Colorado and Washington as examples to demonstrate that legalization will lead to escalating youth cannabis use. But did youth usage really increase in these states after legalization?
Let’s look at Colorado. The Rocky Mountain High Intensity Trafficking Area provides annual reports for Colorado based on the National Survey of Drug Use and Health (NSDUH). Past-month use of cannabis among 12 to 17 year-olds in Colorado was estimated at 6.7 per cent in 2005/2006 before rising to 12.6 per cent in 2013/2014, ranking Colorado’s youth as the leading consumers of cannabis in the U.S. Since this increase took place over a period of time during which recreational cannabis became legal (Colorado voted to legalize cannabis in 2012, with the first state-licensed retail outlets opening in 2014), Conservative MPs charged that legalization was the driver of escalating cannabis use among youth.
However, this implication overlooks the fact that much of the increase took place before legalization. There was only a 1.4-percentage point increase following legalization, which proceeded to drop again by 1.5 percentage points in 2014/2015. Dr. Larry Wolk, Director of the Colorado Department of Public Health and Environment, has also dismissed the claim that legalization led to increased use among young people.
Data from the Healthy Kids Colorado Survey, collected biannually by the Colorado Department of Public Health and Environment and the University of Colorado, further calls this claim’s validity into question. According to the 2015 survey, 21.2 per cent of Colorado high school students reported using cannabis in the previous month — a rate that has remained relatively unchanged from 22 per cent in 2011.
Even if rates in these reports were found to have increased significantly since legalization, any population health researcher would strongly caution against making statements about causality. This is because the changes in state rates were not tested against simultaneous changes in other state rates, and other potential state-level drivers of changing cannabis use patterns were not controlled for in statistical analyses.
Recent peer-reviewed research compared Colorado and Washington rates over a five-year period to 45 states without recreational cannabis and found that cannabis use has not increased significantly among high school students in Colorado since legalization. The study did note that in Washington, rates have increased slightly yet significantly among Grade 8 and 10 students since legalization, alongside noted decreases in perceived harmfulness of cannabis among them.
Claim #2: Cannabis impaired driving and traffic fatalities have increased in Colorado and Washington since legalization