Marijuana Regulation and Teen Use Rates

Since the mid-1990s, self-reported lifetime use of cannabis has fallen 46 percent among 8th-graders, 25 percent among 10th-graders, and ten percent among 12th-graders.

Since 2002, perceived availability of marijuana among young people has fallen dramatically nationwide.

Rates of problematic cannabis use by young people has declined 24 percent between 2002 and 2013.

The enactment of medical cannabis laws is not associated with any causal upticks in youth marijuana use

  • "This systematic review screened 2999 unique papers retrieved from 17 sources, yielding 21 unique studies. Ultimately, 11 studies passed secondary exclusion criteria designed to ensure optimal study quality. ... [A]ll estimates of pre–post changes in past-month marijuana use within MML (medical marijuana law) states from these studies were non-significant. ... In summary, current evidence does not support the hypothesis that MML passage is associated with increased marijuana use prevalence among adolescents in states that have passed such laws."
  • "Of 17 large surveys using difference-in-difference methods spanning different states, periods, and specifications, 16 indicated no MML (medical marijuana laws) effects on adolescent use. Despite differences in methodology, the findings were very consistent: post-MML adolescent cannabis use did not increase compared to pre-MML levels and to national trends in non-MML states during the corresponding years."

The passage of adult use cannabis laws is not associated with any causal upticks in youth marijuana use in those jurisdictions that have enacted them

  • "Certainly the worst things that we had great fear about (the legalization of marijuana for adults in Colorado) – spikes in consumption, kids, people driving while high – we haven't seen any of that. We saw a little increase in teenagers and that came down within a couple years. ... We were very worried that by legalizing, we were making this more somehow more psychologically available to kids. We haven't seen that. If anything, we've seen less drug dealers.”
  • "I think the concern was that by legalizing marijuana, we should certainly see an increase in adult use, and maybe that would leak into our youth. [There was also a concern that] youth would somehow gain greater access, and/or feel entitled to go ahead and use in greater numbers. We just haven't seen that pan out. ... It appears that teenagers make decisions to consume marijuana for reasons other than legalization—like they do with other risk behaviors."