Seattle, WA: The legalization of marijuana for adults is not associated with any increase in cannabis use by young people in Washington's largest metropolitan county (King's County), according to data published in the US Centers for Disease Control and Prevention publication, Morbidity and Mortality Weekly Report.
Researchers from the Public Health Department for Seattle and King County Washington assessed biennial trends in adolescents' reported use of cannabis following the enactment of the state's adult-use cannabis law. Data was gathered via students' responses to the Washington State Healthy Youth Survey.
Authors reported that the enactment of legalization was associated with immediate declines in self-reported, monthly cannabis use among 10th and 12th graders and prolonged declines among 10th graders.
"Despite legalization of the retail sale of marijuana to adults in Washington in 2012, evidence from the biennial Washington State Healthy Youth Survey indicates that the prevalence of past 30-day marijuana use among students in grades 10 and 12 began to decline that year. The decline continued in 2016 among grade 10 students and did not change significantly among grade 12 students," they concluded. "This decline or absence of change in youth marijuana use after legalization of retail sales to adults is consistent with trends reported in Colorado and Oregon, states that legalized adult retail sales of marijuana in 2013 and 2014, respectively."
Full text of the study, "Trends and characteristics in marijuana use among public school students – King County, Washington, 2004-2016," appears in Morbidity and Mortality Weekly Report. Additional information is available from the NORML fact-sheet, 'Marijuana Regulation and Teen Use Rates.'