Acute Effects of MDMA Co-administration on the Response to Psilocybin in Healthy Subjects (MDMA-Psilo)

This randomised, triple-masked, 4-period crossover study will compare single oral doses of psilocybin (20 mg), MDMA (100 mg), their combination, and double placebo in healthy volunteers to assess acute subjective and autonomic responses.

Outcomes include measures of subjective experience, anxiety, empathy and trust, as well as autonomic measures; the study is designed as basic science to test whether MDMA augments positive and reduces negative acute effects of psilocybin.