Adolescents’ cannabis use scrutinized

Researchers are keeping a close eye on a disorder that can develop out of heavy cannabis use, as adolescents gain access to highly potent forms of the drug.

According to the most recently published data by the Substance Abuse and Mental Health Services Administration, roughly 1 million adolescents ages 12 to 17 had cannabis use disorder in 2020.

The behavioral disorder is described as “clinically significant impairment or distress.”  This can include the persistent desire to use the drug, and prioritizing use ahead of obligations at school, home or work.

“Cannabis use disorder mainly starts to appear in adolescence, when adolescents are first using or exposed to cannabis,” said Dr. Nephi Stella, professor of pharmacology and of psychiatry and behavioral sciences at the University of Washington School of Medicine in Seattle. He is the founder of the UW's Center for Cannabis Research.

[Access broadcast-ready video and audio assets of Dr. Nephi Stella discussing adolescent cannabis use. ]

Stella has researched cannabinoid-based molecules for more than two decades. He has studied cannabis' therapeutic value as well as disorders associated with its frequent use.

“It's all about dose and regimen,” he said. “What we're talking about are individuals that are using several times a day continuously.  That's where we know there is the big impact on the developing brain.”

Using cannabis recreationally remains illegal in every U.S. state for anyone under age 21.  Research findings from the IMAGEN Consortium cohort published in JAMA Psychiatry reported that cannabis use during adolescence can alter neurodevelopment.

Stella says the drug itself has evolved with the U.S. wave of cannabis legalization, which has spurred manufacturers to create products packed with much higher percentages of delta-9-tetrahydrocannabinol (commonly known as THC). This is the substance that gives some users a "high." 

“We have an old belief that cannabis is safe, but we need to consider all these new devices where the amount of THC is much higher," said Stella, adding that newer devices allow the drug to be inhaled more rapidly. “It's this higher amount of THC (and the rapid onset of effect) that is creating these new diseases, such as cannabis use disorder.”

A study that tracks year-over-year drug use among 50,000 U.S. teens showed that overall cannabis use actually dropped in 2021. Nevertheless the researchers found that 7.1% of eighth graders, 17.3% of 10th graders, and 30.5% of 12th graders had used the drug during the year. Stella and colleagues at the UW Center for Cannabis Research hope to see diminishing adolescent use become a lasting trend.

“A big goal of what we’re doing is to actually try to educate the population so that they realize that this is a true concern,” he said.

Learn about a research collaboration established by the UW Center for Cannabis Research intended to bring together researchers studying adolescent use worldwide.

Produced by Randy Carnell and Zach Garcia.

UW Medicine