Adverse effects of ayahuasca: Results from the Global Ayahuasca Survey
A global survey of 10,836 ayahuasca users reported high rates of acute physical effects (69.9%, chiefly vomiting) and medium-term psychological effects (55.9%), though most users framed psychological effects as part of a positive integration process and only small proportions required medical (2.3%) or professional (≈12%) help. Risk factors for physical adverse effects included older age at first use, physical health conditions, greater use, prior substance use disorder and unsupervised settings, while mental health effects were linked to anxiety disorders, physical conditions and stronger spiritual experiences but were less common in religious contexts, suggesting targets for screening, support and policy.
Authors
- Milan Scheidegger
- Luiz Tófoli
- Daniel Perkins
Published
Abstract
Introduction
Ayahuasca is a plant-based decoction native to Amazonia, where it has a long history of use in traditional medicine. Contemporary ritual use of ayahuasca has been expanding throughout the world for mental health purposes, and for spiritual and personal growth. Although researchers have been conducting clinical trials and observational studies reporting medical and psychological benefits, most of these do not report ayahuasca’s immediate or medium-term adverse effects, so these are underrepresented in the literature. With the expansion of ayahuasca ceremonies from their traditional contexts to countries around the world, there is an important public health question regarding the risk/benefit balance of its use.
Methods
We used data from an online Global Ayahuasca Survey (n = 10,836) collected between 2017 and 2019 involving participants from more than 50 countries. Principal component analysis was performed to assess group effects. Logistic regression analysis was performed to test for adverse effects associated with history of ayahuasca use, clinical, context of use and spiritual effect variables.
Results
Acute physical health adverse effects (primarily vomiting) were reported by 69.9% of the sample, with 2.3% reporting the need for subsequent medical attention. Adverse mental health effects in the weeks or months following consumption were reported by 55.9% of the sample, however, around 88% considered such mental health effects as part of a positive process of growth or integration. Around 12% sought professional support for these effects. Physical adverse effects were related to older age at initial use of ayahuasca, having a physical health condition, higher lifetime and last year ayahuasca use, having a previous substance use disorder diagnosis, and taking ayahuasca in a non-supervised context. Mental health adverse effects were positively associated with anxiety disorders; physical health conditions; and the strength of the acute spiritual experience; and negatively associated with consumption in religious settings.
Conclusions
While there is a high rate of adverse physical effects and challenging psychological effects from using ayahuasca, they are not generally severe, and most ayahuasca ceremony attendees continue to attend ceremonies, suggesting they perceive the benefits as outweighing any adverse effects. Knowing what variables might predict eventual adverse effects may serve in screening of, or providing additional support for, vulnerable subjects. Improved understanding of the ayahuasca risk/benefit balance can also assist policy makers in decisions regarding potential regulation and public health responses.
Research Summary of 'Adverse effects of ayahuasca: Results from the Global Ayahuasca Survey'
Introduction
Ayahuasca is a traditional Amazonian plant decoction containing harmine, harmaline, tetrahydroharmine (monoamine oxidase inhibitors) typically combined with DMT-containing plants such as Psychotria viridis. Its ritual use has spread internationally in recent decades, often retaining features of traditional practice such as facilitator‑administered group ceremonies. Biomedical interest has increased because observational studies and clinical trials report potential benefits for affective disorders, substance dependence, and other psychological outcomes. However, existing literature has tended to emphasise positive outcomes and comprises relatively small, selective samples, leaving the rates, severity, persistence and contextual determinants of adverse effects underrepresented and uncertain. Bouso and colleagues designed the present study to address these gaps by using data from a large, multi‑country online survey to quantify the frequency of acute physical and short‑to‑medium term mental health adverse effects associated with ayahuasca, and to examine how those adverse effects relate to history of ayahuasca use, clinical and sociodemographic variables, context of consumption, and the intensity of the acute spiritual experience. The aim was to provide a broader empirical picture of ayahuasca’s risk profile across diverse settings and user groups.
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Study Details
- Study Typeindividual
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- APA Citation
Bouso, J. C., Andión, Ó., Sarris, J. J., Scheidegger, M., Tófoli, L. F., Opaleye, E. S., Schubert, V., & Perkins, D. (2022). Adverse effects of ayahuasca: Results from the Global Ayahuasca Survey. PLOS Global Public Health, 2(11), e0000438. https://doi.org/10.1371/journal.pgph.0000438
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