ABSTRACT
Recent studies suggest psychedelic use may be associated with changes in a variety of beliefs or belief-like states, including increased 1) mind perception, 2) non-naturalistic beliefs, and 3) Atheist-Believer status (e.g. believer, agnostic, or nonbeliever). We conducted a prospective longitudinal study among participants (N = 657) who planned to have a psilocybin experience outside a laboratory setting. We asked participants about their beliefs concerning mind perception of various entities, specific metaphysical positions, and Atheist-Believer status both before (and after their experience. Replicating previous findings, we observed increases in mind perception across a variety of living and non-living targets (e.g. plants, rocks). However, we found little to no change in metaphysical beliefs (e.g. dualism) or Atheist-Believer status. Taken together, these findings contrast with those from cross-sectional studies that psilocybin experiences result in changes to Atheist-Believer status and non-naturalistic beliefs but support the relevance of mind perception and mentalization.