Acute Psychological Adverse Reactions in First-Time Ritual Ayahuasca Users

This case studies analysis (n=7 of 40 in an earlier study) of data from first-time ayahuasca users still found positive effects after (or even because of) challenging experiences on mental health six months later. An inappropriate setting/context contributed to the challenging experiences.


Background: In recent decades, ritualistic use of ayahuasca has spread throughout the world. Retrospective studies have suggested a good psychological safety profile, but prospective studies involving ceremony ayahuasca-naive participants are lacking.

Methods: We conducted the study using a subsample from a previous study, for which first-time ceremony ayahuasca participants were recruited. The subsample consisted of 7 subjects who experienced acute and challenging psychological reactions. The semistructured Mini-International Neuropsychiatric Interview and psychometric questionnaires were administered before participants attended the ayahuasca ceremony and at 1 and 6 months after exposure. Subjective experiences were also recorded.

Results: Seven subjects from a sample of 40 reported having experienced intense challenging psychological effects during the ayahuasca ceremony. Four of those 7 subjects met the diagnostic criteria for 1 or more psychiatric disorder before the ayahuasca ceremony. One month after the ceremony, 2 of those subjects no longer showed psychiatric symptoms, whereas the symptoms of the other 2 were reduced considerably. Those results persisted at the 6-month follow-up. Inappropriate setting/context (poor guiding skills and screening) contributed to some of the challenging reactions. Most of the participants (6 of 7) did not take ayahuasca again during the study period.

Conclusions: Based on the cases reported here, we suggest that although it is possible that participating in ayahuasca ceremonies may entail acute psychological negative reactions, those challenging experiences can also have positive long-term effects. Prospective research on the safety profile of ayahuasca and how it is affected by the context of different practices and safety strategies is therefore necessary.”

Authors: María Gómez-Sousa, Daniel F. Jiménez-Garrido, Genís Ona, Rafael Guimaraes dos Santos, Jaime E. C. Hallak, Miguel Ángel Alcázar-Córcoles & José Carlos Bouso


This study is a further analysis of data from Jiménez-Garrido and colleagues (2020). The original study found that 45% of the 40 participants met the criteria for a mental health disorder. And that 80% showed clinical improvements up to six months later.

The introduction to this article highlights the relatively low number of adverse events that happen with the administration of ayahuasca. For instance:

“He also noted that the medical studies section of the União do Vegetal registered between 13 and 24 cases of adverse events in a period of 5 years, in which a total of 25,000 servings were estimated to be given.” (from Gable, 2007)

Which is, in the discussion, contrasted with the relatively high percentage (17.5%) in the current study.

The current study looked at seven participants whose experience was negative and distressful. On average, their scores improved but one participant had since developed another mental health disorder.

The setting was especially negative for two participants. At one, the guide went to sleep whilst people were still under the influence. Whilst at another a person with epilepsy (a contraindication) was allowed to participate.

Finally, the authors note that two participants experienced loss of consciousness and provide a possible neurological explanation.

PDF of Acute Psychological Adverse Reactions in First-Time Ritual Ayahuasca Users