New research shows teens aren’t using more marijuana since legalization

SEATTLE – The annual Washington State Healthy Youth Survey shows marijuana use among teens has remained stagnant over the past 10 years, despite the legalization of marijuana.

Social work researchers say it’s good news, but it doesn’t mean a parents’ job is done, as other trends emerge with the survey results.

“The sky is not falling and that’s an encouraging thing,” said Kevin Haggerty, associate professor at University of Washington’s School of Social Work. Haggerty said the 2016 numbers from the Department of Health are encouraging, but not impressive.

“We’ve seen a big drop in alcohol, we’ve seen a big drop in cigarettes, we’ve seen a drop in e-cigarettes, we’ve not seen a drop, a big significant drop, in marijuana,” he said.

According to the survey of more than 230,000 students, 26 percent of 12th graders reported marijuana use within the last 30 days, 6 percent of 8th graders and 17 percent of 10th graders.

It may come as a surprise to those who voted against I-502, the plan that legalized pot, who feared marijuana availability and use would increase among teens. The study shows that where teens are obtaining marijuana has changed in just the last two years.

“Of those who obtained marijuana in the past month, the percentage buying it at a store decreased from 2014 to 2016 among 8th graders (11% to 5%) and 10th graders (9% to 6%),” reported the survey.

It didn't say how young teens were able to buy pot in licensed stores, but perhaps with fake IDs or having older people buy it for them. But again, that percentage has fallen.

“Parents need to be vigilant in really creating clear guidelines around substance use and in particular, marijuana and alcohol use in their home,” said Haggerty. “Monitor to make sure their kids are following those and setting up consequences that are consistent and fair.”

According to the survey, a 5 percent decline in perceiving a “great risk of regular marijuana use” among 8th graders is concerning. It states that increased use usually follows a decrease in perceived risk."

“I think we have to be really clear that marijuana is potentially addictive. There’s no question,” said Haggerty. “One of the most frequent reasons people go into treatment is because of marijuana addiction. Marijuana is an addictive drug.”

Haggerty said what the numbers don’t show are the number of youths exposed to parental marijuana use at home.

“Parents that are using, are using more frequently,” he said. “One interesting thing we don’t know yet is what the impact of parental modeling might be doing in subsequent years, with kids who are 6, 7 and who have parents in the home that are using.”

He said the survey in 2026 will give better insight into those effects.

“It’s just like pouring yourself a glass of wine at dinner. It normalizes that experience. And the more it normalizes that behavior, the more we’ll see kids imitating that behavior as they become of age.”