Increased frontal and paralimbic activation following ayahuasca, the pan-amazonian inebriant
Jordi Riba, Sergio Romero, Eva Grasa, Esther Mena, Ignasi Carrió, Manel J. Barbanoj
Psychopharmacology March 30, 2006 DOI: 10.1007/s00213-006-0358-7 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Double-blind Peer reviewed |
|---|---|
| Sample size | 15 |
| Population | Male volunteers with prior experience in the use of psychedelics |
| Intervention | Ayahuasca |
| Dose | 1.0 mg DMT/kg body weight |
| Topics | Ayahuasca Serotonin |
| Keywords | Parahippocampal gyrus Hallucinogen Anesthesia |
| Citations | 245 |
| Key findings | Ayahuasca administration increased regional cerebral blood flow in frontal and paralimbic brain regions, including the anterior insula, anterior cingulate/frontomedial cortex, and left amygdala/parahippocampal gyrus. |
Abstract
RationaleAyahuasca is a South American psychoactive plant tea which contains the serotonergic psychedelic N,N-dimethyltryptamine (DMT) and monoamine-oxidase inhibitors that render DMT orally active. Previous investigations with ayahuasca have highlighted a psychotropic effect profile characterized by enhanced introspective attention, with individuals reporting altered somatic perceptions and intense emotional modifications, frequently accompanied by visual imagery. Despite recent advances in the study of ayahuasca pharmacology, the neural correlates of acute ayahuasca intoxication remain largely unknown.ObjectivesTo investigate the effects of ayahuasca administration on regional cerebral blood flow.MethodsFifteen male volunteers with prior experience in the use of psychedelics received a single oral dose of encapsulated freeze-dried ayahuasca equivalent to 1.0 mg DMT/kg body weight and a placebo in a randomized double-blind clinical trial. Regional cerebral blood flow was measured 100-110 min after drug administration by means of single photon emission tomography (SPECT).ResultsAyahuasca administration led to significant activation of frontal and paralimbic brain regions. Increased blood perfusion was observed bilaterally in the anterior insula, with greater intensity in the right hemisphere, and in the anterior cingulate/frontomedial cortex of the right hemisphere, areas previously implicated in somatic awareness, subjective feeling states, and emotional arousal. Additional increases were observed in the left amygdala/parahippocampal gyrus, a structure also involved in emotional arousal.ConclusionsThe present results suggest that ayahuasca interacts with neural systems that are central to interoception and emotional processing and point to a modulatory role of serotonergic neurotransmission in these processes.
In the evidence
This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.
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State of the evidence: Ayahuasca Supports
Ayahuasca increased regional cerebral blood flow in frontal and paralimbic regions including the anterior insula, anterior cingulate/frontomedial cortex, and left amygdala/parahippocampal gyrus.
Synthesized
Comparable studies
Other randomized controlled trials on ayahuasca, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial Patients with treatment-resistant depression | 2018 | Randomized controlled trial | n = 29 |
| Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Volunteers with prior experience in the use of psychedelics | 2003 | Double-blind placebo-controlled clinical trial | n = 18 |
| Subjective effects and tolerability of the South American psychoactive beverage Ayahuasca in healthy volunteers Healthy male volunteers with prior experience using ayahuasca | 2001 | Single-blind crossover placebo-controlled clinical trial | n = 6 |
| Human brain effects of DMT assessed via EEG-fMRI. Healthy volunteers | 2023 | Within-subjects, placebo-controlled design | n = 20 |
| Effects of ayahuasca on psychometric measures of anxiety, panic-like and hopelessness in Santo Daime members Members of the Santo Daime religion who ingested ayahuasca for at least 10 consecutive... | 2007 | Double-blind, placebo-controlled study |
Citations in the library
Cited by 194
- Safety and Efficacy of Lysergic Acid Diethylamide-Assisted Psychotherapy for Anxiety Associated With Life-threatening Diseases The Journal of Nervous and Mental Disease March 4, 2014
- The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future. Neuropsychopharmacology April 26, 2017
- Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms. Scientific Reports October 13, 2017
- Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a preliminary report Brazilian Journal of Psychiatry March 1, 2015
- Antidepressant Effects of a Single Dose of Ayahuasca in Patients With Recurrent Depression Journal of Clinical Psychopharmacology December 11, 2015
and 189 more in the library
Cites 19
- Meditation experience is associated with increased cortical thickness Neuroreport November 7, 2005
- Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action Neuroreport December 1, 1998
- Dose-Response Study of N,N-Dimethyltryptamine in Humans Archives of General Psychiatry February 1, 1994
- Monoamine oxidase inhibitors in South American hallucinogenic plants: Tryptamine and β-carboline constituents of Ayahuasca Journal of Ethnopharmacology April 1, 1984
- Human Pharmacology of Ayahuasca: Subjective and Cardiovascular Effects, Monoamine Metabolite Excretion, and Pharmacokinetics Journal of Pharmacology and Experimental Therapeutics June 18, 2003
and 14 more in the library