WSU study: Teen weed use down overall, but higher among working high school seniors

So far, the fear that teen marijuana use would skyrocket once weed became legal has not been the reality. Teen marijuana use has stayed steady, even slightly dipped, since legalization in Washington, according to state survey data.

But you, loyal reader, already knew that.

There is, however, one group of teens who report using marijuana more since legalization. That would be high school seniors who work more than 11 or more hours a week, according to a study using data from the state's Healthy Youth Survey.

The study was led by Washington State University College of Nursing assistant professor Janessa Graves, and it was published in the Journal of Adolescent Health.

The gap in marijuana use between working and nonworking teens is wide. For nonworking high school seniors, the number who said they used marijuana in 2016 is about one in five, and dropped by about 3 percent since 2010. But it increased by 3 percent among working seniors, up to 36.7 percent, according to the study.

Among 10th graders in 2016, roughly 14 percent of nonworkers reported using marijuana in the past 30 days, about 4 percent less than nonworkers in 2010. Among 10th graders working 11-plus hours per week, one-third reported using marijuana in 2016 (still five percent less than in 2010).

Graves says the data from the Healthy Youth Survey "are very reliable," since it is consistent with other state and federal surveillance systems.

"There is really no other way to get this type of information from teens — you just have to ask them," Graves says.

Why do working teens smoke so much more weed? It's likely because they're around adults who smoke weed. According to the paper, "A large body of research has demonstrated the importance of social influence on adolescent substance use. This includes the modeling of substance use, such as by older co-workers for whom substance use is more normative." (As the study notes, teen weed use is associated with lower academic attainment, dependence and other mental health consequences).

The study suggests that workplaces should enforce zero-tolerance policies with regards to providing substances to co-workers or endorsing substance use.

The study did not look at teen marijuana use across socioeconomic statuses, but it suggests doing so for future studies.

"This research reports the findings of only one study, and more work is needed to truly understand the factors that contribute to teen decision-making related to substance use and poly-substance use," Graves says.