The vanguard industry is booming despite a host of regulatory unknowns, as practitioners educate themselves on the therapeutic potential of psilocybin—and other drugs such as cannabis and methylenedioxymethamphetamine (MDMA)—while betting on imminent federal legalization.

There are dozens of these schools, including the California Institute of Integral Studies, which offers a certificate in psychedelic-assisted therapies and research. Naropa, a Buddhist university in Boulder, Colo., began offering a course in MDMA-assisted psychotherapy last year. Compass Pathways Plc, which received a "breakthrough therapy" designation from the U.S. Food and Drug Administration, also offers a core training curriculum.