Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users: An observational study.
Manoj K. Doss, Lilian Kloft, Natasha L. Mason, Pablo Mallaroni, Johannes T. Reckweg, Kim van Oorsouw, Nina Tupper, Henry Otgaar, Johannes G. Ramaekers
Journal of Psychopharmacology April 1, 2025 DOI: 10.1177/02698811241301216 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study Peer reviewed |
|---|---|
| Sample size | 24 |
| Population | Experienced Santo Daime members with >500 lifetime ayahuasca uses |
| Intervention | Ayahuasca |
| Dose | average dose contained 3.36 and 170.64 mg of N,N-dimethyltryptamine and β-carbolines, respectively |
| Topics | Ayahuasca |
| Keywords | Episodic memory False memory Familiarity Psychedelics Recollection Memory enhancement Cognitive effects Santo daime |
| Citations | 5 |
| Key findings | Ayahuasca enhanced recollection and memory accuracy but did not affect familiarity or false memory in experienced users. |
Abstract
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). 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. 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). 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. 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.
Comparable studies
Other observational and cohort studies on ayahuasca, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a preliminary report Patients with a depressive disorder | 2015 | Observational study | |
| The Psychedelic State Induced by Ayahuasca Modulates the Activity and Connectivity of the Default Mode Network Experienced subjects | 2015 | Observational cohort | n = 10 |
| Human Psychopharmacology of Hoasca, A Plant Hallucinogen Used in Ritual Context in Brazil Long-term members of a syncretic church that uses hoasca as a psychoactive sacrament... | 1996 | Observational cohort with matched controls | n = 30 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Personality, Psychopathology, Life Attitudes and Neuropsychological Performance among Ritual Users of Ayahuasca: A Longitudinal Study Regular ayahuasca users and active controls in non-ayahuasca religions | 2012 | Observational cohort | n = 242 |
Citations in the library
Cited by 6
- Clinical pharmacology of ayahuasca: potential applications and future considerations Expert Review of Clinical Pharmacology October 3, 2025
- Psychedelics do not always enhance cognitive flexibility: The potential role of time-varying effects on reward learning processes Neuroscience & Biobehavioral Reviews May 30, 2026
- Perspectives on Meditation-based Preparation for Psychedelic Experiences: Insights from Practitioners with Combined Meditation and Psychedelic Experience Mindfulness August 15, 2026
- Effects of ayahuasca on neuropsychological performance and social cognition: A systematic review. Journal of Psychopharmacology March 9, 2026
- The therapeutic potential of ayahuasca in depression, generalized anxiety, and substance use disorders: modulation of the depressive burden in a longitudinal study. Frontiers in Psychiatry 2026
and 1 more in the library
Cites 51
- Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial Psychological Medicine June 15, 2018
- Antidepressant Effects of a Single Dose of Ayahuasca in Patients With Recurrent Depression Journal of Clinical Psychopharmacology December 11, 2015
- Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Journal of Pharmacology and Experimental Therapeutics June 18, 2003
- Human Psychopharmacology of Hoasca, A Plant Hallucinogen Used in Ritual Context in Brazil The Journal of Nervous and Mental Disease February 1, 1996
- Personality, Psychopathology, Life Attitudes and Neuropsychological Performance among Ritual Users of Ayahuasca: A Longitudinal Study PLoS One August 8, 2012
and 46 more in the library