Malin Uthaug

Malin Uthaug, PhD

Maastricht University

Mind or matter? A placebo-controlled study of the effects of ayahuasca ingestion on mental health of participants in a naturalistic, neo-shamanic setting.


Background: Ayahuasca is a plant concoction containing N,N-dimethyltryptamine (DMT) and certain β-carboline alkaloids from South America. Previous research in naturalistic settings has suggested that ingestion of ayahuasca can improve mental health and well-being, however these studies were not placebo controlled and did not control for the possibility of expectation bias.

Aims: This naturalistic observational study was designed to assess whether mental health changes were produced by ayahuasca (matter), or by set (mind).

Methods: Assessments were made at pre and post-ayahuasca sessions in 30 participants of ayahuasca retreats of naturalistic, neo-shamanic origin hosted in The Netherlands, Spain and Germany. Participants were randomized into two treatment groups that ingested capsules containing ayahuasca (N = 14) or placebo (N = 16).

Results: Analysis revealed a main effect of Session on symptoms of depression, anxiety and stress. Compared to baseline, symptoms reduced in both groups after the ceremony, independent of treatment. There was a main Treatment x Session interaction on implicit emotional empathy, indicating that ayahuasca increased emotional empathy to negative stimuli.

Conclusion: The current findings suggest that subjective improvements in mental health of participants of naturalistic ayahuasca ceremonies can be driven by non-pharmacological factors such as expectations and intentions (mind-set). Yet, objective measures of empathy also revealed improvements that were solely observed after the pharmacological treatment with ayahuasca (matter). These findings stress the importance of placebo-controlled designs in psychedelic research and the need to further explore the contribution of non-pharmacological factors to the psychedelic experience.


Malin completed her PhD at the department of Neuropsychology and Psychopharmacology, at the faculty of Psychology and Neuroscience at Maastricht University, The Netherlands. As part of her PhD, she investigated the short-term and long-term effects of Ayahuasca and 5-MeO-DMT in naturalistic settings, while simultaneously initiating several other studies on the psychedelic substance Mescaline and the breathing practice known as Holotropic Breathwork (HB).Malin is currently working as a Postdoctoral researcher at The Centre for Psychedelic Research, at Imperial College London, led by Dr. Robin Carhart-Harris. Here she is investigating the effects of 5-MeO-DMT and Holotropic Breathwork on mental health related variables, emobodiment, brain activity and consciousness.

Besides being a researcher, Malin is also a scientific advisor for Entheon Biomedical, an editor for the ‘Journal of Psychedelics Studies’, a board member of the American podcast-show known as Psychedelics Today, and the co-founder of the Norwegian Association for Psychedelic Science (Norsk Forening for Psykedelisk Vitenskap [NFPV]) whose main aim is to educate the general public as well as researchers, and mental health practitioners in Norway about psychedelics.



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