Poison centers in the U.S. reported a large jump in the number of calls related to psilocybin, or “magic mushrooms,” among teens and young adults after several cities and states began decriminalizing the hallucinogen, a new study finds.

Calls related to psilocybin more than tripled among teens ages 13 to 19 – from 152 to 464 – and more than doubled among adults ages 20 to 25 – from 125 to 294 – between 2018 and 2022, the study found. Beginning in 2019, several cities and states began efforts to decriminalize the possession, use and cultivation of psilocybin. Oregon and Colorado have decriminalized psilocybin, as have several cities, including Washington, D.C., Detroit and Seattle, HealthDay reports.

Between 2013 and 2018, before psilocybin was decriminalized, poison center calls for patients ages 13 to 25 related to the hallucinogen remain largely unchanged.

The researchers note that the increase is particularly worrisome because psilocybin remains banned for those under 21 even in places where it has been decriminalized.

“It is markedly concerning to me that children are gaining access to these products,” researcher Christopher Holstege, M.D. of the University of Virginia said in a news release. “We have limited data on the potential long-term consequences on the developing brains of children when exposed to such compounds that impact the brain’s neurotransmission.”