Validation of the revised Mystical Experience Questionnaire in experimental sessions with psilocybin

Abstract

The 30-item revised Mystical Experience Questionnaire (MEQ30) was previously developed within an online survey of mystical-type experiences occasioned by psilocybin-containing mushrooms. The rated experiences occurred on average eight years before completion of the questionnaire. The current paper validates the MEQ30 using data from experimental studies with controlled doses of psilocybin. Data were pooled and analyzed from five laboratory experiments in which participants (n=184) received a moderate to high oral dose of psilocybin (at least 20 mg/70 kg). Results of confirmatory factor analysis demonstrate the reliability and internal validity of the MEQ30. Structural equation models demonstrate the external and convergent validity of the MEQ30 by showing that latent variable scores on the MEQ30 positively predict persisting change in attitudes, behavior, and well-being attributed to experiences with psilocybin while controlling for the contribution of the participant-rated intensity of drug effects. These findings support the use of the MEQ30 as an efficient measure of individual mystical experiences. A method to score a “complete mystical experience” that was used in previous versions of the mystical experience questionnaire is validated in the MEQ30, and a stand-alone version of the MEQ30 is provided for use in future research.

Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial

“…Thirty items on the SOCQ comprise the Mystical Experience Questionnaire (MEQ30), which was shown sensitive to mystical-type subjective effects of psilocybin in laboratory studies as well as survey studies of recreational use of psilocybin mushrooms (Barrett et al, 2015; MacLean et al, 2012). Four factor scores (Mystical, Positive mood, Transcendence of time and space, and Ineffability) and a mean total score (the mean of all 30 items) were assessed.…”

Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences

“…their worst “bad trip”), they were asked questions about the estimated dose of psilocybin consumed, the set and setting conditions in which the session occurred, the duration of the difficult experience, strategies attempted and that helped to stop the experience, and acute negative consequences of the experience. As with laboratory studies of psilocybin (Griffiths et al, 2006, 2011), the phenomenology of the psilocybin experience was assessed using three questionnaires: Hallucinogen Rating Scale (HRS) (Strassman et al, 1994); Mystical Experience Questionnaire – 30 item version (MEQ30) which is part of the States of Consciousness Questionnaire (Barrett et al, 2015; Griffiths et al, 2006; MacLean et al, 2011); and selected subscales from the 5D-ASC (Studerus et al, 2010). Data analyzed for this report were the six subscales of the HRS (expressed as raw scores) and the total and four subscales of the MEQ30 (expressed as percentages of maximum possible scores).…”

DMT Models the Near-Death Experience

“…The EDI contains 8 items and a mean score on all 8 is calculated for a single EDI factor. The MEQ contains 30 items and yields a total score consisting of the average of all items as well as four subscales: Mystical, Positive Mood, Transcendence of Time and Space and Ineffability (Maclean et al, 2013; Barrett et al, 2015). …”