Topographic pharmaco-EEG mapping of the effects of the South American psychoactive beverage ayahuasca in healthy volunteers
Abstract
Aims: Ayahuasca is a traditional South American psychoactive beverage used in Amazonian shamanism, and in the religious ceremonies of Brazilian-based syncretic religious groups with followers in the US and several European countries. This tea contains measurable amounts of the psychotropic indole N,N-dimethyltryptamine (DMT), and β-carboline alkaloids with MAO-inhibiting properties. In a previous report we described a profile of stimulant and psychedelic effects for ayahuasca as measured by subjective report self-assessment instruments. In the present study the cerebral bioavailability and time-course of effects of ayahuasca were assessed in humans by means of topographic quantitative-electroencephalography (q-EEG), a noninvasive method measuring drug-induced variations in brain electrical activity.
Methods: Two doses (one low and one high) of encapsulated freeze-dried ayahuasca, equivalent to 0.6 and 0.85 mg DMT kg−1 body weight, were administered to 18 healthy volunteers with previous experience in psychedelic drug use in a double-blind crossover placebo-controlled clinical trial. Nineteen-lead recordings were undertaken from baseline to 8 h after administration. Subjective effects were measured by means of the Hallucinogen Rating Scale (HRS).
Results: Ayahuasca induced a pattern of psychoactive effects which resulted in significant dose-dependent increases in all subscales of the HRS, and in significant and dose-dependent modifications of brain electrical activity. Absolute power decreased in all frequency bands, most prominently in the theta band. Mean absolute power decreases (95% CI) at a representative lead (P3) 90 min after the high dose were −20.20±15.23 µV2 and −2.70±2.21 µV2 for total power and theta power, respectively. Relative power decreased in the delta (−1.20±1.31% after 120 min at P3) and theta (−3.30±2.59% after 120 min at P3) bands, and increased in the beta band, most prominently in the faster beta-3 (1.00±0.88% after 90 min at P3) and beta-4 (0.30±0.24% after 90 min at P3) subbands. Finally, an increase was also seen for the centroid of the total activity and its deviation. EEG modifications began as early as 15–30 min, reached a peak between 45 and 120 min and decreased thereafter to return to baseline levels at 4–6 h after administration.
Conclusions: The central effects of ayahuasca could be objectively measured by means of q-EEG, showing a time pattern which closely paralleled that of previously reported subjective effects. The modifications seen for the individual q-EEG variables were in line with those previously described for other serotonergic psychedelics and share some features with the profile of effects shown by pro-serotonergic and pro-dopaminergic drugs. The q-EEG profile supports the role of 5-HT2 and dopamine D2-receptor agonism in mediating the effects of ayahuasca on the central nervous system.
Riba, J., Anderer, P., Morte, A., Urbano, G., Jané, F., Saletu, B., & Barbanoj, M. J. (2002). Topographic pharmaco‐EEG mapping of the effects of the South American psychoactive beverage ayahuasca in healthy volunteers. British journal of clinical pharmacology, 53(6), 613-628. 10.1046/j.1365-2125.2002.01609.x
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The sensationalism surrounding the widespread use of LSD in the late 60s and the subsequent legislative overkill virtually ended psychotherapeutic LSD research. Much of what had been learned over thirty years of scientific medical study was so distorted or suppressed that no objective overview was available to the general reader – except for this book. LSD Psychotherapy is a complete account of a remarkable chapter in the ever-continuing inquiry into our transpersonal nature and origins. The controlled studies described in this book reveal exciting and challenging data about the nature of human consciousness, perception, and reality itself. Drawing on this work Dr. Stanislav Grof outlines a new cartography of the human mind, one which accounts for experiences such as shamanic trance, near-death experiences and altered states of consciousness. This vision is also the foundation for Dr. Grof’s revolutionary new Holotropic Breathwork™ techniques. This book is also a visual feast, with numerous color drawings and paintings created by research participants (see featured artist Sherana Harriette Frances’ book Drawing It Out: Befriending the Unconscious). Many of these depict archetypal images from the collective human consciousness, which form a powerful addition to the text. LSD Psychotherapy is a valuable source of information for those who are involved with LSD in any way, as parents, teachers, researchers, legislators, or students of the human psyche. The approach to healing described in this book is inspired by the eternal desire of humankind for wholeness and an enduring grasp of reality.
From 1990 to 1995 Dr. Rick Strassman conducted U.S. Government-approved and funded clinical research at the University of New Mexico in which he injected sixty volunteers with DMT, one of the most powerful psychedelics known. His detailed account of those sessions is an extraordinarily riveting inquiry into the nature of the human mind and the therapeutic potential of psychedelics. DMT, a plant-derived chemical found in the psychedelic Amazon brew, ayahuasca, is also manufactured by the human brain. In Strassman’s volunteers, it consistently produced near-death and mystical experiences. Many reported convincing encounters with intelligent nonhuman presences, aliens, angels, and spirits. Nearly all felt that the sessions were among the most profound experiences of their lives.
