DENVER (AP) – Colorado voters have passed a ballot initiative to decriminalize psychedelic mushrooms for people 21 and older and to create state-regulated centers where participants can experience the drug.

Colorado becomes the second state after Oregon to establish a regulated system for substances like psilocybin and psilocin, the hallucinogens found in some mushrooms. Colorado’s initiative eventually will allow an advisory board to add other plant-based psychedelic drugs to the program.

Proponents argued that the state’s current approach to mental health has failed and that naturally occurring psychedelics can treat depression, PTSD, anxiety and addiction.

Critics said decriminalization would jeopardize public safety.