Effects of ayahuasca on neuropsychological performance and social cognition: A systematic review.

A systematic review of 16 studies found that ayahuasca has distinct short- and long-term cognitive effects. In the short term, improvements in working memory and cognitive flexibility were observed, linked to neurochemical modulation of cortical networks. Observational studies reported increased empathy and emotion recognition, while experimental studies only found reduced reaction times in social cognition tasks. Long-term studies generally found no neuropsychological deficits, with some reporting improved memory and executive function. The review notes methodological limitations including small sample sizes, varied protocols, and potential learning effects, calling for more controlled, randomized studies.

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Abstract

Ayahuasca has aroused increasing interest due to its therapeutic effects. However, its effects on cognition are poorly understood. Hence, a systematic review evaluating the cognitive effects of ayahuasca was conducted. This systematic review was conducted in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A comprehensive search was performed in PubMed, Web of Science, PsycINFO, SciELO, and LILACS using terms related to ayahuasca, neuropsychology, and social cognition, encompassing all studies published up to March 25, 2025. Human observational, experimental, and clinical studies assessing neuropsychological performance or social cognition following ayahuasca administration were included. Titles, abstracts, and full texts were independently screened by two reviewers, with disagreements resolved with a third reviewer. A total of 16 articles were selected, including observational (n = 11) and experimental (n = 5) studies. The results indicated distinct effects of ayahuasca on cognition. In the short term, improvements in functions such as working memory and cognitive flexibility were observed and attributed to neurochemical modulation of cortical networks. Regarding social cognition, observational studies have reported an increase in empathy and emotion recognition, while experimental studies have only observed reduction in reaction times. Long-term studies in general did not observe neuropsychological deficits, with some studies reporting improved memory and executive function. Although these findings are promising, there are methodological limitations, such as small sample sizes, diverse administration protocols, the observational nature of several studies, and possible learning effects. Further controlled, randomized studies are needed to elucidate the underlying mechanisms and consolidate the evidence. The PROSPERO ID for this study is CRD42024559125.