Altered States of Consciousness During Ceremonial San Pedro Use
This open-label ceremonial use study (n=42) investigates the consciousness altering effects of San Pedro, a mescaline containing cactus, in ceremonial psychedelic retreats in Europe. Results indicate that San Pedro induces deviations from normal waking consciousness on all 11 subscales of the 11D-ASC, moderate scores of ego-dissolution, and a complete mystical experience in two thirds of participants.
Authors
- Johannes Ramaekers
- Morten Uthaug
- Kim Oorsouw
Published
Abstract
San Pedro, a mescaline-containing cactus, has been used for thousands of years and is currently popular as a psychedelic substance in ceremonial retreats in Europe. The current research investigates the consciousness-altering effects of San Pedro. Forty-two participants who joined ceremonial psychedelic retreats in the Netherlands were investigated with questionnaires probing 11 dimensions of altered states of consciousness (11D-ASC), ego-dissolution, mystical experiences, and challenging experiences. Results tentatively demonstrate the status of San Pedro as a psychedelic, revealing deviations from normal waking consciousness on all 11 subscales of the 11D-ASC, moderate scores of ego-dissolution, and a complete mystical experience in two thirds of the participants. Furthermore, a consciousness profile of San Pedro was constructed, which revealed that spiritual experiences are strongly expressed in ceremonial San Pedro use. Furthermore, the San Pedro experience is characterized by low levels of disembodiment, anxiety, impaired control and cognition, transcendence of space, and relatively higher levels of physical distress and grief in case of (incidental) challenging experiences. Finally, graph network analysis indicated two separate networks of positive and negative altered states of consciousness. Possible interpretations of these findings are discussed in relation to the ceremonial setting, sympathomimetic effects of San Pedro’s alkaloids and variations in affective valence.
Research Summary of 'Altered States of Consciousness During Ceremonial San Pedro Use'
Introduction
Bohn and colleagues situate San Pedro (Echinopsis pachanoi), a mescaline-containing cactus with a long Andean ceremonial history, within the recent rise of Western ceremonial use and note a striking absence of psychological research focused exclusively on its subjective effects. Earlier work on classical serotonergic psychedelics has linked altered states of consciousness (ASC), mystical-type experiences and ego-dissolution to therapeutic outcomes, while also recognising that challenging experiences can cause harm; the authors highlight that San Pedro contains mescaline plus a range of other alkaloids that may produce both serotonergic and sympathomimetic effects, potentially shaping a distinct ASC profile. They further emphasise that set and setting, including ceremonial guidance, are likely to influence subjective reports, complicating attributions solely to the drug. The study sets out to provide a first observational characterisation of consciousness changes during ceremonial San Pedro use. Specifically, the investigators aimed to: (1) determine whether ceremonial San Pedro consumption produces ASC that differ from normal waking consciousness; (2) construct a consciousness profile by comparing relative strengths of different ASC dimensions; and (3) identify which ASC co-occur during San Pedro experiences. Given San Pedro’s history and its pharmacology, the authors expected overall psychedelic-like effects but did not make specific predictions about the relative patterning of ASC across subscales or their interrelations.
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Study Details
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- APA Citation
Bohn, A., Kiggen, M. H. H., Uthaug, M. V., van Oorsouw, K. I. M., Ramaekers, J. G., & van Schie, H. T. (2023). Altered States of Consciousness During Ceremonial San Pedro Use. The International Journal for the Psychology of Religion, 33(4), 309-331. https://doi.org/10.1080/10508619.2022.2139502
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