Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users: An observational study

This observational study (n=24) examines the acute effects of ayahuasca on memory in experienced Santo Daime members (>500 lifetime uses). Findings show ayahuasca enhances memory accuracy and recollection while not impacting familiarity or false memory, suggesting β-carboline activity may drive selective improvements in hippocampal-dependent processes.

Abstract of Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users

Background: Ayahuasca is an Amazonian brew with 5-HT2A-dependent psychedelic effects taken by religious groups globally. Recently, psychedelics have been shown to impair the formation of recollections (hippocampal-dependent episodic memory for specific details) and potentially distort memory while remembering. However, psychedelics spare or enhance the formation of familiarity-based memory (cortical-dependent feeling of knowing that a stimulus has been processed).

Aims: Given the growing literature on the plasticity-promoting effects of psychedelics, we investigated the acute impact of ayahuasca on recollection, familiarity, and false memory in an observational study of 24 Santo Daime members with >500 lifetime ayahuasca uses on average.

Methods: Participants completed a false memory task at baseline and after they consumed a self-selected dose of ayahuasca prepared by their church (average dose contained 3.36 and 170.64 mg of N,N-dimethyltryptamine and β-carbolines, respectively).

Results: Surprisingly, pre-encoding administration of ayahuasca enhanced hit rates, memory accuracy, and recollection but had no impact on familiarity or false memory. Although practice effects cannot be discounted, these memory enhancements were large and selective, as multiple measures of false memory and metamemory did not improve across testing sessions. β-carboline activity potentially accounted for this recollection enhancement that diverges from past psychedelic research. Although ayahuasca did not impact familiarity, these estimates were generally elevated across conditions compared to past work, alluding to a consequence of frequently driving cortical plasticity.

Conclusions: When encoding and retrieval took place under acute ayahuasca effects in experienced ayahuasca users, susceptibility to memory distortions did not increase, potentially owing to enhancements in memory accuracy.”

Authors: Manoj K. Doss, Lilian Kloft, Natasha L. Mason, Pablo Mallaroni, Johannes T. Reckweg, Kim van Oorsouw, Nina Tupper, Henry Otgaar & Johannes G. Ramaekers

Summary of Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users

The introduction establishes ayahuasca as a traditional Amazonian brew comprising DMT (N,N-dimethyltryptamine) and β-carbolines derived from specific plants. While DMT is known for its rapid degradation in the body, the β-carbolines in ayahuasca inhibit an enzyme called monoamine oxidase A (MAO-A), making DMT orally active. The psychoactive effects of ayahuasca, similar to other psychedelics like psilocybin and LSD, are mediated mainly through the activation of 5-HT2A receptors. These receptors are implicated in therapeutic research, particularly for treating conditions such as depression. Uniquely, DMT also interacts with σ receptors, which may support the growth of new neurons in the hippocampus, a brain region critical for memory.

Ayahuasca’s composition includes β-carbolines that influence memory-related processes beyond those impacted by typical psychedelics. These compounds can act on GABA receptors and may have psychoactive properties themselves. Regular ayahuasca use by religious groups has allowed researchers to study the long-term neurocognitive effects of repeated psychedelic use. Previous studies suggest that psychedelics could influence memory by altering hippocampal and cortical plasticity. These changes might allow individuals to revise negative memories but also increase the risk of forming false memories.

Methods

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Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users: An observational study

https://doi.org/10.1177/02698811241301216

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Cite this paper (APA)

Doss, M. K., Kloft, L., Mason, N. L., Mallaroni, P., Reckweg, J. T., van Oorsouw, K., ... & Ramaekers, J. G. (2024). Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users: An observational study. Journal of Psychopharmacology, 02698811241301216.

Study details

Compounds studied
Ayahuasca

Participants
24 Humans

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