Pilot study comparing the effects of high dose THC to high dose psilocybin and placebo in the set and setting of a classic psychedelic therapy session

This double-blind, placebo-controlled crossover pilot study (n=4) compared oral Δ9-THC (25 or 50 mg) with psilocybin (25 mg) and placebo in healthy adults during a psychedelic therapy-style session. A 25 mg dose of Δ9-THC produced subjective effects similar to psilocybin, and some participants mistook it for a classic hallucinogen.