New research from the University of Washington has found that legalizing marijuana for the Washington state adults may be slowing reducing the use of marijuana in teens.

Lead author of the study Jennifer Bailey said, “When we think about marijuana legalization, a worry is that underage use may go up. Early use and heavy use during adolescence can have a lot of negative health consequences, then and later in life, so we don’t want teen use to be going up.”

She noted that before marijuana legalization, rates of marijuana and other drug use among teens had been decreasing over the last couple of decades.

The study, published in the American Journal of Preventive Medicine, examined whether the legalization of marijuana led to teen marijuana use.

The researchers found that kids who recently entered their teens were less likely to use marijuana in the past year, which goes along with the steady downward trend in teen substance use.

Bailey said that she thinks that these findings could mean that marijuana legalization may be working against the decreases in teen marijuana use seen in the recent past.

Previous studies have also shown that the rates of teen marijuana use decreased slightly after the legalization of the drug.

Bailey said, “They [surveys] can only see how a whole state changes over time. Data like ours let you look at individuals and how drug use and behavior change over time, and then we can relate that to changes in policy.”

In the current study, marijuana use was assessed in participants between the ages of 10 and 20.

Bailey credited the downward trend in teen marijuana use to years of “drug prevention” and “education efforts” in schools and communities.

However, the study did not find an overall connection between marijuana legalization and perceived harm from the drug among teens. The researchers noted, “It could be that changing societal attitudes drive changes in marijuana laws rather than that changing laws drive perceptions.”

“People generally like to take care of themselves. They don’t typically do things that carry risk of harm,” Bailey said. “Throughout the decades that we’ve been tracking marijuana use, this highly correlates with whether someone will use or not.”

The study also found no association between marijuana legalization and decreased cigarette smoking among teens, according to Bailey. Nationwide, teen smoking has declined precipitously for years – thanks to higher taxes, strict restrictions, and widespread public health warnings.

Bailey explained that the study findings could help inform prevention messages targeting teens about the use of marijuana.

She said, “A teen usage rate that holds steady isn’t good enough if it would normally be going down.” “We need to devote more attention to prevention of adolescent use in the context of legalization because we want to keep the decreases we’ve been seeing before legalization was implemented,” Bailey added.