State laws liberalizing marijuana’s criminal status are not associated over the long-term with any significant uptick in youth use, according to data published in The American Journal of Drug and Alcohol Abuse.
A team of researchers from Boston College assessed marijuana use data in a cohort of 860,000 adolescents from 45 states over a period of 16 years (1999 to 2015).
They reported that states which enacted medical cannabis access laws experienced overall reductions in teen use compared to non-legal states, and that this decrease grew stronger over time. “We found that for every group of 100 adolescents, one fewer will be a current user of marijuana following the enactment of medical marijuana laws,” the study’s lead researcher said in a press release.
Investigators also reported that state laws decriminalizing marijuana penalties for recreational use did not experience “significant shifts in use for the sample as a whole,” though they acknowledged a minor uptick in self-reported use among whites and a small decline in consumption among Hispanics and those 14 years of age.
They added, “Neither policy was significantly associated with heavy marijuana use or the frequency of use, suggesting that heavy users may be impervious to such policy signals.”
Authors concluded, “[These] results assuage concerns over potential detrimental effects of more liberal marijuana policies on youth use.”
The findings are consistent with those of dozens of prior studies concluding that neither liberalizing marijuana penalties nor regulating retail cannabis access is typically associated with increases in young people’s use of cannabis or its availability.