Does Cannabis Legalization Increase Youth Use?
According to 10 years of research, the answer is no
Phoebe Harkin | | Quick Read
To date, 36 states in the US have legalized medical cannabis and 18 have passed recreational marijuana laws (RMLs). With the rising green tide came a Helen Lovejoy-esque concern that legalization would encourage youth cannabis use. But data from the Youth Risk Behavior Survey (YRBS) from 1993–2017 has shown little evidence that RMLs or medical marijuana laws (MMLs) encourage youth cannabis use (1).
In fact, the overall association between RML adoption and cannabis use among adolescents was statistically indistinguishable from zero. RML adoption was not associated with current or frequent cannabis use (and, in the fully adjusted models, MML adoption was associated with a 6 percent decrease in the odds of current cannabis use and a 7 percent decrease in the odds of cannabis marijuana use). The same story applies to the association between cannabis use and the opening of the first recreational dispensary.
Of course, the study has its limitations – for one, RMLs are a relatively new phenomenon – but, as more post-legalization data become available, the picture can only become clearer.
We spoke to lead author, Mark Anderson, Associate Professor at the Department of Agricultural Economics and Economics, Montana State University, USA, to find out more
Where do you think this myth of legalization increasing youth use comes from? Is it damaging?
A good question! I'm not sure about the origins of this perception. It has been around for a long time (think Reefer Madness of the 1930s) and I think it can take away focus from sound research-based policy prescriptions. That being said, whether or not legalization increases teen use is an extremely important and policy-relevant line of inquiry. When we think about the costs and benefits of legalization, this is indeed an important piece of the puzzle.
Were you surprised to find the overall association between RML adoption and cannabis use among adolescents statistically indistinguishable from zero?
This is now the third paper I have published finding that MMLs, RMLs – or both – are not associated with an increase in teen use. So, given my prior work (and the work of others), I was not at all surprised that this general result has continued to hold up.
Is there a reason why, in the fully adjusted models, MML adoption was associated with a decrease in the odds of current and frequent marijuana use?
From a statistical perspective, I would not read too much into this as the point estimates from the non-fully adjusted models are contained in the confidence intervals for the estimates based on the fully adjusted models. In other words, the estimates across the non-fully vs. fully adjusted models are not statistically distinguishable from one another.
Did you find any variation across states or were the results similar?
Unlike MMLs, RMLs do not vary as much across states in terms of their implementation. Though we did not probe heterogeneity across RML states, my guess would be that the results would be largely similar.
You mention a limitation of the study being that RMLs are a relatively new phenomenon; do you expect the results to differ significantly in years to come?
Another good question and maybe a bit hard to say. Only the data will tell!
- D Anderson et al., “Association of Marijuana Legalization With Marijuana Use Among US High School Students, 1993-2019”, JAMA Netw Open, 4, 9 (2021). PMID: 34491352