Role of the Serotonin 5-HT2A Receptor in Mescaline-induced Altered States of Consciousness

This randomized, quadruple-blind, placebo-controlled crossover study characterises subjective and psychometric effects of escalating oral mescaline doses (100, 200, 400, 800 mg) in healthy volunteers and examines the contribution of the 5-HT2A receptor using ketanserin pre-treatment.

Six treatment conditions are administered across separate single-dose sessions with washouts; outcomes include acute subjective measures, pharmacodynamics and safety assessments to determine the role of 5-HT2A signalling in mescaline-induced altered states.