UW News

March 9, 2015

Study shows teens and adults hazy on Washington marijuana law

News and Information

More than two years after Washington legalized marijuana, parents and teens may be hazy on the specifics of the law, if the findings of a new study are any indication.

University of Washington research, published recently in Substance Use & Misuse, found that only 57 percent of Washington parents surveyed knew the legal age for recreational marijuana use and just 63 percent knew that homegrown marijuana is illegal under the law.

And while 71 percent of 10th-graders correctly identified the legal age, fewer than half (49 percent) knew how much marijuana can legally be possessed.

The findings underscore the need for better educational outreach about the law, said co-author Kevin Haggerty, professor of social work and director of the Social Development Research Group at the University of Washington’s School of Social Work.

“As new states are taking on legalized marijuana, we need to have public information campaigns to make sure people have the information they need,” he said.

The study surveyed 115 low-income families of teens attending Tacoma middle schools, who were part of an ongoing prevention study. Data was initially collected before Washington approved recreational marijuana, and then two years later during the summer of 2013.

The study found that while 70 percent of parents said they talked about marijuana laws with their children, those conversations were infrequent. That is troubling, Haggerty said, since 10th grade is a critical time for family discussions about drug use.

“We know that parent expectations, even as late as senior year in high school, have an impact on kids’ college-age marijuana use,” he said. “If kids are thinking in 10th grade that the legal age for marijuana is 18, they could potentially be more likely to use it later.”

The study also found that the Washington law made little difference in the teens’ attitudes about marijuana use or the likelihood of them smoking pot.

“We were most surprised to see how little parents and teens know about fundamental aspects of the new law, such as the legal age limit,” said corresponding author W. Alex Mason, director of research at the Boys Town National Research Institute.

In 2012, Washington and Colorado became the first U.S. states to legalize recreational marijuana use, and Alaska, Oregon and Washington, D.C. passed marijuana legalization measures last November. The legal age for marijuana use in Washington is 21. Adults can possess up to one ounce, and homegrown pot is prohibited.

The study comes at a time when educators, parents and others are trying to determine what young people need to know about marijuana use and what messages might most effectively steer them away from it.

The Washington State Department of Health launched a $400,000 statewide campaign in June that featured ads on radio and digital media encouraging parents to talk to their kids about the risks of using marijuana. The UW’s Alcohol & Drug Abuse Institute has also launched an education website which is expected to eventually be supported by marijuana tax revenues.

Washington’s law mandates that a portion of revenues from marijuana sales be used for public education, drug abuse treatment and research, and stipulates that the state consult with the UW annually to decide which programs to fund. The department of health plans to launch a broader education campaign when marijuana revenues become available later this year.

“This study convincingly points out that people don’t have good information about the new law,” Haggerty said.

Other co-authors are Koren Hanson and Charles Fleming at the UW and Jay L. Ringle at Boys Town Research Institute. The work was funded by the National Institute on Drug Abuse.