CA STUDY: Frequent cannabis use among teenagers on the rise post-legalization

SAN DIEGO (FOX 5/KUSI) -- A peer-reviewed study published in the Journal of Adolescent Health found that frequent cannabis use among 11th graders in California has been steadily rising after adult-use cannabis retailers legally opened throughout the state in 2018, according to a press release Monday from the Public Health Institute.

The study, Local Cannabis Policy and Cannabis Use by California High School Students Before and After Statewide Retail Legalization, was co-authored by researchers from UC Irvine, UCLA and the Public Health Institute's Get it Right from the Start program.

The study collected data from the California Healthy Kids Survey (CHKS), an annual cross-sectional survey administered by the Department of Education to 7th, 9th, and 11th-grade students. The data collected originated before legalization in 2015-16 and continued through 2021-22, encompassing more than 370,000 California teens.

The survey revealed that frequent cannabis use among 11th graders increased after legalization. Before the recreational sale of cannabis in 2018, studies showed that daily or near-daily use among California 11th graders was declining. After legalization, the trend reversed and began steadily climbing in 2020.

The study focused on the impact of local policy on cannabis use and whether daily use differed in conjunction with local city and county allowance of storefront and delivery cannabis sales.

According to the press release, "Jurisdictions that banned retail cannabis sales consistently saw lower rates of youth use both before and after legalization. In contrast, rates stayed higher in places that newly permitted storefront sales, while medical–delivery–only jurisdictions did not see increases."

The study also concluded that frequent use has coincided with increases in cannabis potency and the sale of highly concentrated products like vapes and wax, which reportedly carry a greater risk of dependency and potential psychosis, according to the press release.

According to the Department of Cannabis Control, a person can legally purchase cannabis in California if they are 18 years of age with a physician’s recommendation (medicinal use), or if they can buy it without a recommendation if they are 21 or older (adult use).