Ceremonial Ayahuasca in Amazonian Retreats—Mental Health and Epigenetic Outcomes From a Six-Month Naturalistic Study

This open-label (naturalistic) study (n=63) found that participants in ayahuasca retreats improved in scores of mental health (depression, anxiety, self-compassion), these effects lasted and were even somewhat improved at the 6-month follow-up. A study of participant’s epigenetic data didn’t yield conclusive results.


Ayahuasca is a natural psychoactive brew, used in traditional ceremonies in the Amazon basin. Recent research has indicated that ayahuasca is pharmacologically safe and its use may be positively associated with improvements in psychiatric symptoms. The mechanistic effects of ayahuasca are yet to be fully established. In this prospective naturalistic study, 63 self-selected participants took part in ayahuasca ceremonies at a retreat centre in the Peruvian Amazon. Participants undertook the Beck Depression Inventory (BDI-II), State-Trait Anxiety Inventory (STAI), Self-compassion Scale (SCS), Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM), as well as secondary measures, pre- and post-retreat and at 6-months. Participants also provided saliva samples for pre/post epigenetic analysis. Overall, a statistically significant decrease in BDI-II (13.9 vs. 6.1, p < 0.001), STAI (44.4 vs. 34.3 p < 0.001) scores, and CORE-OM scores were observed (37.3 vs. 22.3 p < 0.001) at post-retreat, as well as a concurrent increase in SCS (3.1 vs. 3.6, p < 0.001). Psychometric improvements were sustained, and on some measures values further decreased at 6-month follow-up, suggesting a potential for lasting therapeutic effects. Changes in memory valence were linked to the observed psychometric improvements. Epigenetic findings were equivocal, but indicated that further research in candidate genes, such as sigma non-opioid intracellular receptor 1 (SIGMAR1), is warranted. This data adds to the literature supporting ayahuasca’s possible positive impact on mental health when conducted in a ceremonial context. Further investigation into clinical samples, as well as greater analyses into the mechanistic action of ayahuasca is advised.

Authors: Simon G. D. Ruffell, Nige Netzband, WaiFung Tsang, Merlin Davies, Matthew Butler, James J. H. Rucker, Luís F. Tófoli, Emma L. Dempster, Allan H. Young & Celia J. A. Morgan


Many studies have been pointing out that the mental health of people can be improved after going to an ayahuasca retreat. There is an ongoing debate surrounding the different factors leading to this positive change. As people go in with many expectations, could it be that most of the positive outcomes are placebo effects? Or could it be that people who participate in a retreat are at their worst in terms of mental health? And thus a ‘regression to the mean’ takes place, where people become better but that this would have happened regardless of the retreat.

The current paper isn’t able to address these issues head-on. The participants in the study were self-selected and there was no placebo being used. That all being said, the study did confirm some findings that other studies have previously found. Significant improvements in mental health, and these effects being sustained six months later.

The outcomes of the study

  • Of those who were depressed before the retreat, 77% were no longer qualified as such after the retreat and at the 6-month follow-up
  • Scores on all the measures (depression, anxiety, lack of self-compassion) were significantly lower after the retreat and this effect held up at the follow-up (i.e. stayed low)
  • Genetic analysis of the participants didn’t show any noteworthy results, partly because the analysis of BDNF was not done due to an error

If we put aside all the reasons why mental health improves after an ayahuasca retreat, we can still wonder at the impressive effect size. A single retreat led to 77% of participants who were depressed no longer qualifying for depression.

The researchers propose that a reduction in the valence, or strength, of negative emotions is a possible explanation for the reduction in depression scores. If negative memories are recalled less, and less intensively, one might break free of the thought loops that we spoke about last week.

Become a psychedelic insider!

With a free Blossom membership you will always be in the know.

📰 Weekly newsletter about the psychedelic research

✔️ Unlimited access to our database and original articles

🖊️ Add (private) notes and comments to each page

Make an account

Study details

Compounds studied

Topics studied
Anxiety Depression

Study characteristics


Inline Feedbacks
View all comments