Double-blind, placebo-controlled study (n=40) using single or repeated all-day oral psilocybin sessions to examine acute and persisting effects on meditation, spirituality, well-being, prosocial attitudes and brain function in long-term meditators.
Randomized, double-blind, parallel-design study in long-term meditators comparing moderately-high oral psilocybin to placebo across arms with one, two or three all-day sessions; an optional MRI arm examines acute effects with very-low or moderately-low doses.
Primary measures include questionnaires on meditation, spirituality, well-being and prosocial attitudes, and functional MRI to assess brain function; procedures include screening, preparatory meetings (approximately 8 hours), supervised dosing sessions, and follow-ups at 1 day, 2 months and 12–18 months.
Safety screening excludes participants with major medical or psychiatric conditions, recent substance dependence, or family history of psychosis; women of child-bearing potential must use effective contraception.
Single all-day session with a moderately-high oral dose of psilocybin; includes preparatory meetings and follow-up imaging and questionnaires.
Moderately-high oral dose (exact mg unspecified).
Lactose placebo.
Two all-day sessions: first placebo, second moderately-high psilocybin; preparatory meetings and follow-ups after each session.
Placebo session.
Moderately-high oral dose (exact mg unspecified).
Three all-day sessions: first two placebo, third moderately-high psilocybin; minority assigned to this arm.
Placebo sessions (two).
Moderately-high oral dose on third session.
Optional MRI arm with very-low or moderately-low psilocybin or placebo administered shortly before scanning; one or two sessions.
Moderately-low oral dose (dose unspecified).
Very-low oral dose (dose unspecified).
Lactose placebo.