Neural and subjective effects of inhaled DMT in natural settings

Abstract

N,N-Dimethyltryptamine (DMT) is a short acting psychedelic tryptamine found naturally in many plants and animals. When combined with a monoamine oxidase inhibitor, such as in the Amazonian brew known as ayahuasca, DMT becomes orally active and its effects are extended. Few studies to date addressed the neural and psychological effects of DMT alone, either administered intravenously or inhaled in freebase form, and none conducted in natural settings. We combined state-of-the-art wireless electroencephalography (EEG) with psychometric questionnaires to study the acute effects of inhaled DMT in 35 participants in natural settings, focusing on questions tuned to the advantages of conducting field research, including the effects of contextual factors (known as set and setting), the possibility of studying a comparatively large number of subjects, and the relaxed mental state of participants consuming DMT in familiar and comfortable settings. We observed that DMT significantly decreased the power of alpha (8-12 Hz) oscillations throughout all scalp locations, while simultaneously increasing power of delta (1-4 Hz) and gamma (30-40 Hz) oscillations. The pharmacokinetics of inhaled DMT was similar to intravenous administration, but we observed a faster return to baseline for power in the alpha band. Gamma power increases correlated with subjective reports indicative of mystical-type experiences. DMT also increased/decreased global synchrony and metastability in the gamma/alpha band, and resulted in widespread increases in signal complexity measured using the Lempel-Ziv algorithm. These results are consistent with previous studies of psychedelic action in the human brain, while at the same time suggesting potential EEG markers of mystical-type experiences in natural settings. In summary, we conducted one of the first field studies on the neural and psychological effects of a serotonergic psychedelic, yielding new insights and advancing our understanding of the translation between laboratory findings and those obtained in the contexts where these compounds are most frequently consumed.

An Encounter With the Other: A Thematic and Content Analysis of DMT Experiences From a Naturalistic Field Study

“…In this way, no personal, identifiable information from the participant such as name, phone number or address was shared or recorded, and all reporting of data was anonymised. Naturalistic field research with psychoactive substances has previously been successful with ayahuasca and with neural and psychometric measures of DMT ( Kuypers et al, 2016 ; Pallavicini et al, 2020 ).…”

Restructuring insight: An integrative review of insight in problem-solving, meditation, psychotherapy, delusions and psychedelics

“…It is hypothesized that psychedelics create an enhanced feeling of meaning and knowing, which can accompany trivial and often even banal "understandings", as well as deeper and more beneficial insights (Baggot, 2015;Hartogsohn, 2018;Carhart-Harris and Friston, 2019;Timmermann et al, 2020;Mason et al, 2021). Some studies suggest that while psychedelics increase the "feeling" of creativity and insight, this may not be reflected in the actual novelty or fidelity of ideas generated during the experience (Mason et al, 2021;Baggot, 2015;2020a).…”

“…These types of spontaneous and unrestrained mental activity could be instrumental in inducing insights (Mason et al, 2021;Kraehenmann et al, 2017b, Carhart-Harris andFriston, 2019;Timmermann et al, 2020).…”

Natural Language as a Window into the Subjective Effects and Neurochemistry of Psychedelic Drugs

“…Perhaps the most widely adopted approach for the study of psychedelic compounds in humans is that of self-reported questionnaires (right upper quadrant in Figure 1, left), including versions that can be completed even when undergoing intense effects, such as visual analogue scales (VAS). Over the past decade, an ample variety of questionnaires has been proposed to investigate how psychedelics affect cognition, conscious perception, thought processes, as well as beliefs, attitudes, and personality traits, and their results have been correlated with objective measurements of brain activity obtained using neuroimaging techniques such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG) (Dittrich, 1998;Studerus et al, 2010;Barrett et al, 2015;Carhart-Harris et al, 2012;Muthukumaraswamy et al, 2013;Kometer et al, 2015;Tagliazucchi et al, 2016;Barrett, et al, 2016;Nour et al, 2016;Preller et al, 2018;Kettner et al, 2019;Roseman et al, 2019;Timmermann et al, 2019;Pallavicini et al, 2020;Tagliazucchi et al, 2021) Figure 1. Natural language processing as a method to investigate the effects of psychedelic drugs.…”