Marijuana use by teens fell significantly in King County, Washington (population: 2.3 million) following the state’s adoption of adult-use legalization, according to data provided by the US Centers for Disease Control and Prevention.
Investigators reported that cannabis use fell 60 percent among males and 42 percent among females from 2012 to 2021. (Voters approved a ballot initiative legalizing the adult use market in 2012; retail cannabis sales began in 2014.)
The study’s authors suggested that legalization likely made it more difficult for teens to access cannabis.
“The observed overall decreases in cannabis use among students in grades 8, 10, and 12 might be associated with changes in the availability of cannabis among persons aged ≥21 years as well as limited opportunities to engage in use,” they wrote. “The period 2012–2014 includes the legalization of nonmedical cannabis in Washington in 2012. Researchers studying the association of cannabis laws with cannabis use among high school students have observed similar declines in cannabis use after legalization of nonmedical cannabis. The legalization of nonmedical cannabis for adults aged ≥21 years in Washington with licensed dispensaries requiring proof of age might have affected availability of cannabis to younger persons as well as their opportunities to engage in its use. This, in turn, might have had an impact on use prevalence.”
The authors’ findings are consistent with those of several other studies documenting declines in young people’s use of cannabis following states’ adoption of adult-use legalization laws.
Full text of the study, “Cannabis use among students in grades 8. 10, and 12, by sex: King County, Washington, 2008-2012,” is available from the Centers for Disease Control and Prevention. Additional information is available from the NORML Fact Sheet, ‘Marijuana Regulation and Teen Use Rates.’