Teens living in areas with a higher number of cannabis retailers are more likely to be diagnosed with mental health disorders, including psychosis, depression and anxiety, a new study finds. The research, co-authored by Getting it Right from the Start — a program of the Public Health Institute — and Kaiser Permanente Northern California, analyzed data from nearly 96,000 insured adolescents across Northern California.
The study found that teens in cities or counties that banned cannabis storefronts were less likely to have a recent diagnosis of a psychotic disorder. In contrast, greater retail availability — measured by the number of nearby cannabis shops and their proximity to teens’ homes — was associated with higher rates of diagnosed psychotic, depressive and anxiety disorders, as well as self-reported depressive symptoms.
However, some experts and advocates are urging caution in interpreting these results. The study’s authors themselves acknowledge that their cross-sectional design cannot establish causation between cannabis retailer proximity and mental health outcomes.
Some critics of similar research have also pointed out that, in states like California where medical marijuana is legal for minors with a doctor’s recommendation, there may be additional factors influencing diagnosis rates among teens. However, the study did not specifically investigate whether teens are seeking diagnoses in order to obtain medical marijuana.
The study’s authors acknowledge these limitations, noting that their research cannot establish direct cause and effect. Dr. Lynn Silver, pediatrician and director of Getting it Right from the Start, maintains that the findings are still important. “This study reinforces the importance of where and how cannabis is sold in protecting adolescent mental health, showing significant impacts — even on severe conditions like psychosis,” Silver said.
Despite nearly half of teens living in areas with local storefront bans, the median drive time to the nearest cannabis retailer was just 10 minutes, according to the study. Researchers argue this highlights the limits of local policy and the need for broader regulations on retailer density and access.
Legalization supporters, however, say that regulated cannabis markets are safer for everyone, including youth.
“Legalization is not a cure-all, but it allows us to regulate and control the market, keep it away from kids, and educate people about responsible use,” Gieringer said. “Prohibition just drives the market underground and makes it harder to protect public health.”
The debate comes as more states legalize cannabis and communities grapple with how to balance adult access with youth protection. The study’s authors say more research is needed to understand the true relationship between cannabis retail availability and adolescent mental health.
