Yes. According to the nation’s largest and most comprehensive survey of drug use trends in the nation, past-month use of marijuana among 12-17 year olds in Colorado increased significantly – from 9.82% to 12.56% after marijuana retail sales began (Colorado legalized marijuana in 2012 and implemented legal marijuana stores in 2014). The same study notes that teens and adults in Colorado now use marijuana at a higher rate than the rest of the country.
Youth use is also increasing in Washington State. According to a study published in The Journal of American Medical Association Pediatrics, the perceived harmfulness of marijuana in Washington declined 14.2% and 16.1% among eighth and 10th graders, respectively, while marijuana use increased 2.0% and 4.1% from 2010-2012 to 2013-2015.
Media reporting and statements from politicians noting stable or declining youth drug use rates in Colorado likely stem from a non-representative sample found in the state’s Healthy Kids Colorado Survey (HKCS), which excludes both the second most-populous and third-most populous counties in Colorado altogether (Jefferson and Douglas Counties). Also, the survey designers decided, without explanation, to set the threshold for statistical significance far higher in their survey, meaning that differences that would usually be statistically significant would not appear to be so under the new standard. (In response, a group of scientists recently wrote to Governor Hickenlooper urging him to stop saying drug use has not gone up in the state.)