Högskolan i Skövde

Background: Ayahuasca is a South American psychoactive brew that contains Dimethyltryptamine (DMT) and monoamine oxidase inhibitors (MAOIs). Research has experienced a resurgence of interest in exploring the potential of these substances in the last decade. Thus, the aim of this review was to systematically review studies that used a placebo-controlled design to explore the neural correlates and psychedelic experience induced by DMT and ayahuasca.

Method: The search was conducted using the Web of Science and Scopus databases to select studies published between January 2000 and February 2022 that used neuroimaging techniques and recruited healthy participants. Thus, 7 papers were selected.

Results: Ayahuasca alters electrical activity in the brain by decreasing spectralpower in all EEG frequency bands, predominantly in the alpha band. DMT caused a spatially widespread decrease in alpha bands and a more modest decrease in beta bands. Ayahuasca caused an increase in the flow of information in the brain from posterior regions to more frontal regions and an increase in scores in all the Hallucinogen Rating Scale (HRS) subscales. Ayahuasca decreased connectivity in the Default Mode Network (DMN) and increases connectivity between DMN and the salience network.

Conclusion: Ayahuasca and DMT can reliably produce profound changes in perception, emotions, and sense of self. Moreover, the decrease in the alpha band, the alteration of information flow between posterior and frontal regions, and the decrease in connectivity in the DMN could be the keystone understanding the neural correlates and the psychedelic experience induced by DMT andayahuasca.