In this survey study, we investigate how people describe and understand their psychedelic experiences and try to assess to what extent instruments capture these. A main goal is to assess whether the mystical experience questionnaire primes participants to think and talk about their experiences in a certain way. See https://osf.io/a56dt/ for the project and read our opinion piece Moving Past Mysticism in Psychedelic Science here: https://pubs.acs.org/doi/10.1021/acsptsci.1c00097