Marijuana use among teens declined this year even as two states, Colorado and Washington, legalized the drug for recreational use, a national survey released Tuesday found.
University of Michigan's Monitoring the Future study, now in its 40th year, surveys 40,000 to 50,000 students in 8th, 10th and 12th grade in schools nationwide about their use of alcohol, legal and illegal drugs and cigarettes.
"There is a lot of good news in this year's results, bu the problems of teen substance use and abuse are still far from going away," Lloyd Johnston, the study's principal investigator, said.
After five years of increases, marijuana use in the past year by students in all three grades declined slightly, from 26% in 2013 to 24% in 2013.