By their very definition, psychedelic drugs cause dramatic changes in the mind and its perceptual pathways.1 Also, by definition, classical psychedelics are agonists of the serotonin 5-HT2A receptor, one of several in the GPCR (G protein-coupled receptor) family. When Humphry Osmond first coined the term in 1957, he was trying to explain the effects LSD had on the mind.2 After much thought…