OAKLAND, Calif. (April 17, 2026) -- Teen cannabis use in Northern California increased following the legalization of adult recreational cannabis and later declined during the COVID-19 pandemic, according to new research from Kaiser Permanente published in JAMA Network Open.
"We saw adolescent cannabis use begin to rise after legalization was passed and before retail sales began," said lead author Kelly Young-Wolff, a research scientist with the Kaiser Permanente Division of Research. "This suggests that changes in social norms and perceptions may play an important role in shaping teen behavior."
The study analyzed 1.3 million well-child pediatric visits among Kaiser Permanente patients aged 13 to 17 between 2011 and 2024. At each well-child visit, adolescents completed a confidential screening questionnaire that included questions about substance use.
Cannabis use among teens had been steadily declining for years prior to legalization, from 10.4% reporting past-year use in 2011 to 6.8% in 2016, the year California voters approved recreational cannabis. After legalization, rates began increasing, reaching 8.1% in 2017 and 9.5% in 2018, and continued to rise as retail sales were implemented.
The authors suggested the increase may reflect shifting perceptions and greater access. Adolescents may have viewed cannabis as more socially acceptable and less risky, alongside increased availability, lower prices, and the rise of vaping products, including flavored options.
Additional studies are needed to better understand how local cannabis policies, including retail access and advertising, affect adolescent cannabis use following state legalization, the researchers said.
The findings are consistent with national data showing declines in adolescent substance use during the pandemic. Possible contributing factors include reduced social interaction, increased parental supervision, and decreased access to substances.
