Study Suggests Minimum Age of Legal Cannabis Use Should Be 19

Newfoundland, Canada: Jurisdictions that regulate the use of cannabis by adults ought to consider imposing a minimum age requirement of 19, according to data published in the journal BMC Public Health.

A team of researchers affiliated with the Memorial University of Newfoundland assessed life outcomes, such as educational attainment and mental health, associated with the use of cannabis at different ages.

They reported: “In this study, we assumed that setting an MLA (minimum legal age) for cannabis use is necessary … and sought to determine an ‘optimal’ MLA. The choice of an MLA represents a trade-off that policymakers face between curtailing illegal economic activity versus safeguarding adolescents’ well-being.”

Authors concluded: “While the (Canadian) medical community recommended an MLA of 21 or 25 based on neuroscientific evidence about adverse impacts of cannabis on cognitive development, this would lead to a large underground market for cannabis. On the contrary, policymakers have decided on a lower MLA such as 18 or 19 to curb the size of underground market, but this raises concerns about adverse outcomes for adolescents. This study, however, found that later life outcomes associated with first using cannabis at age 19 are better than those associated with first using it at age 18, but not significantly different from those first using between 21 and 25. … Our results suggest that there is merit in setting 19 as the MLA for non-medical cannabis use.”

Both Uruguay and Canada regulate non-medical cannabis use for those ages 18 and older, while all US jurisdictions that permit adult-use possession limit legal cannabis use to those ages 21 or older.

Full text of the study, “Too young for cannabis? Choice of minimum legal age for legalized non-medical cannabis in Canada,” appears in BMC Public Health.