Researchers Pinpoint the Ideal Legal Age for Cannabis Use
Since it was legalized in Canada in 2018, most provinces have required consumers to be at least 19-years-old before they can buy recreational cannabis. But in the United States, states with legal recreational access still require buyers to be at least 21. So, which age limit works best?
Well, according to researchers from Memorial University of Newfoundland, Canada, most provinces in their home nation have it right: 19 years of age is the ideal age limit for buying adult-use cannabis.
At this age, the negative impacts cannabis can have on mental health, physical health, and educational attainment are minimized, the researchers say.
21 is too high
To decide upon a suitable age limit for purchasing cannabis, the researchers trawled through data from tobacco and alcohol surveys conducted in Canada between 2004 and 2015.
Attention was given to the 20,000 respondents’ educational attainment, current cigarette use, and self-reported general and mental health. The researchers chose not to focus on employment, as there is currently limited evidence on its association with marijuana.
In support of an age limit of 19, the researchers found that respondents who first used cannabis aged 19-20 were less likely to smoke cigarettes later in life than those who first used cannabis aged 18.
However, education levels were higher in respondents who first used cannabis when aged between 21 and 24. But, in further support for a minimum age limit (MAL) of 19, mental health outcomes were found to be better in respondents who first used cannabis aged 19-20.
When all variables were considered, a MAL of 19 seemed to be the threshold with the fewest drawbacks on wellbeing.
“Taking into account all measured outcomes, our results indicate that, contrary to the Canadian federal government's recommendation of 18 and the medical community's support for 21 or 25, 19 is the optimal minimum legal age for non-medical cannabis use,” Dr Hai Nguyen, the lead author of the study, said in a statement.
To help undermine the strength of the illicit cannabis market, Canada’s federal government actually recommended a MAL of 18 for recreational cannabis consumption when it legalized the drug in 2018. However, Alberta is the only province to follow this guidance. Most provinces opted for a MAL of 19, while Quebec raised its MAL to 21 this January.
“Keeping the legal age below 21 may strike a balance between potential increases in underground markets and illegal use, and avoiding the adverse outcomes associated with starting to use cannabis at an earlier age,” Nguyen added.
But is 19 too low?
While Nguyen’s study may validate the choices of most Canadian provinces, the debate over marijuana’s MAL is far from settled.
Other researchers have argued that, since younger brains are more sensitive to drug exposure, the MAL for cannabis consumption should be between 21 and 25.
A nationwide poll conducted in 2018 found that 27 percent of Canadians would prefer a MAL of 18, while 26 percent favored the higher MAL of 21.
Nguyen’s study also relied on self-reported data, which may limit its conclusions. The survey results used were also sourced prior to the legalization of recreational cannabis in Canada, which may have affected how individuals use cannabis, tobacco, and alcohol.
So, to properly ascertain which age threshold is best suited for cannabis consumption, more research into other factors, such as driving behaviours, will be needed, Nguyen’s study concludes.