Investigating the Interaction of Psilocybin and Context of Its Administration in Healthy Volunteers

One hundred twenty healthy participants, ages 21 to 70, who experience moderate-to-lower-than-average mental well-being will be evenly randomized into four different study arms, using a 2x2 factorial design. Depending on the study arm, participants will either receive an inactive placebo or up to 25mg psilocybin (oral dose), in one of two set and setting conditions; drug administration contexts that are predicted to modulate drug effects. The purpose of this study is to evaluate any interaction effects between an oral dose of psilocybin and the surrounding context (set and setting).