PLoS ONE
February 18, 2015
Fernanda Palhano-Fontes, Kátia C. Andrade, Luís Fernando Tófoli et al.
461 citations
Ayahuasca, a psychedelic brew used traditionally by Amazonian Amerindians, significantly reduces activity in key hubs of the Default Mode Network (DMN), specifically the Posterior Cingulate Cortex (PCC)/Precuneus and medial Prefrontal Cortex (mPFC), as measured by fMRI in ten experienced subjects. Functional connectivity within the PCC/Precuneus also decreased after intake, while the orthogonality between the DMN and task-positive network showed no significant change. These findings suggest that the altered state of consciousness induced by Ayahuasca, similar to effects from psilocybin, meditation, and sleep, involves modulation of DMN activity and connectivity.
Human Brain Mapping
September 16, 2011
Dráulio Barros de Araújo, Sidarta Ribeiro, Guillermo Cecchi et al.
241 citations
Ayahuasca, a hallucinogenic brew containing serotonergic agonists and reuptake inhibitors, triggers vivid visual imagery during ceremonies. Using functional magnetic resonance imaging while participants performed a closed-eyes imagery task, the brew produced a robust increase in activation across occipital, temporal, and frontal brain areas. In the primary visual area, activation levels matched those of natural image viewing with eyes open. This effect correlated with individual perceptual changes measured by psychiatric scales. Activity in areas BA30 and BA37, linked to episodic memory and contextual associations, was also potentiated. Modulation of BA10, involved in prospective imagination and working memory, was detected. The findings suggest Ayahuasca seeings arise from an extensive network for vision, memory, and intention, lending a sense of reality to inner experiences.
European Neuropsychopharmacology
January 16, 2015
José Carlos Bouso, Fernanda Palhano-Fontes, Antoni Rodrı́guez-fornells et al.
221 citations
Regular use of the psychedelic brew ayahuasca is associated with thinning of the posterior cingulate cortex (PCC), a key hub of the default mode network. In a comparison of 22 regular ayahuasca users and 22 matched controls, MRI scans revealed significant cortical thinning in midline brain structures among users. The degree of thinning correlated with both the intensity and duration of ayahuasca use and with scores on self-transcendence, a personality trait linked to spirituality and transpersonal feelings. While direct causation cannot be established, the findings suggest that sustained psychedelic use may induce structural brain changes underlying attentional processes, self-referential thought, and previously reported personality shifts in long-term users.
Scientific reports
October 9, 2017
Vanja Dakic, Juliana Minardi Nascimento, Rafaela Costa Sartore et al.
137 citations
5-MeO-DMT, a serotonin-like molecule found in traditional Amerindian medicine, alters the protein landscape of human cerebral organoids. Out of 6,728 identified proteins, 934 were differentially expressed after treatment. Computational analysis confirmed previously reported anti-inflammatory effects and revealed modulation of proteins involved in long-term potentiation, dendritic spine formation, cellular protrusion, microtubule dynamics, and cytoskeletal reorganization. These findings provide initial molecular insights into how this compound may affect human brain metabolism.
Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999)
January 1, 2021
Alvaro V Jardim, Dora V Jardim, Bruno Rasmussen Chaves et al.
54 citations
In Brazil's first clinical trial of MDMA-assisted psychotherapy for post-traumatic stress disorder (PTSD), three patients with PTSD from sexual abuse completed treatment. The protocol involved 15 weekly therapy sessions, with three sessions including orally administered MDMA combined with psychotherapy and music, spaced about a month apart. Two months after the final MDMA session, all three patients showed clinically significant improvement, with CAPS-4 scores dropping by more than 30% from baseline. Final scores were 61, 27, and 8, down from 90, 78, and 72. No serious adverse events occurred; common side effects were somatic pains and anguish. Secondary outcomes also improved. MDMA-assisted psychotherapy could become a viable PTSD treatment in Brazil.
Psychological medicine
March 1, 2023
Isabel Wießner, Marcelo Falchi, Fernanda Palhano-Fontes et al.
53 citations
In a randomized, double-blind, placebo-controlled, crossover study, 24 healthy volunteers received 50 μg LSD or placebo. LSD produced psychedelic experiences, including altered consciousness, mystical experiences, ego-dissolution, and mildly challenging experiences, and increased aberrant salience and suggestibility, but not mindfulness. LSD-induced aberrant salience correlated strongly with complex imagery, mystical experiences, and ego-dissolution. Suggestibility changes from LSD did not correlate with other effects. The results suggest the LSD state resembles psychosis and may offer a therapeutic tool, with mystical experiences linking the psychosis model and therapeutic potential. Meaning attribution appears important for the LSD psychosis model, and psychedelic-assisted therapy might benefit from suggestions that foster mystical experiences.
Journal of Psychopharmacology
February 1, 2022
Isabel Wießner, Marcelo Falchi-Carvalho, Lucas Oliveira Maia et al.
43 citations
A randomized, double-blind, placebo-controlled crossover study gave 24 healthy volunteers 50 micrograms of LSD or an inactive placebo and tested creativity near the drug's peak using multiple tasks. LSD changed creativity in three ways: it increased novelty, surprise, originality, and semantic distances (pattern break); decreased utility, convergent thinking, and marginally elaboration (disorganization); and increased symbolic thinking and ambiguity (meaning). The findings suggest LSD shifts cognitive resources away from normal patterns toward new ones, and that LSD-induced symbolic thinking might aid psychedelic-assisted therapy.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
May 1, 2022
Isabel Wießner, Rodolfo Olivieri, Marcelo Falchi et al.
42 citations
A low dose of LSD (50 μg) produces both beneficial and detrimental cognitive effects 24 hours after administration. Compared to placebo, LSD sub-acutely improved visuospatial memory and phonological verbal fluency but impaired cognitive flexibility, as measured by fewer categories achieved and more perseveration on the Wisconsin Card Sorting Test. The findings suggest that LSD-assisted therapy might be explored for conditions involving memory and language decline, such as brain injury, stroke, or dementia, while also indicating a mixed 'afterglow and hangover' profile.
Frontiers in psychology
January 1, 2020
Sergio A Mota-Rolim, Kelly Bulkeley, Stephany Campanelli et al.
31 citations
Religions have long recognized lucid dreaming (LD) as an important conscious state, predating modern scientific study by millennia. Hindu texts over 2,000 years old divide consciousness into waking, dreaming (including LD), and deep sleep. Tibetan Buddhists practice Dream Yoga to recognize dreams, overcome fears, and control dream content. Islam regards LD as a valuable mental state for mystical experiences. Christian theologian Augustine described LD as a preview of the afterlife. Spiritism in the nineteenth century linked LD to out-of-body experiences. Abrahamic religions view dreams as communication with God, while Indian traditions cultivate self-awareness through LD induction techniques. These historical religious insights can inform current scientific research on LD phenomenology.
Psychopharmacology
June 1, 2022
Isabel Wießner, Marcelo Falchi, Fernanda Palhano-Fontes et al.
22 citations
LSD alters the stream of thought in multiple ways, increasing chaos, meaning, and abstractness at different times after ingestion. In a randomized, double-blind, placebo-controlled crossover study with 24 healthy participants, 50 μg LSD compared to placebo induced facets of mind-wandering labeled 'chaos' (discontinuity of mind, decreased sleepiness and planning), 'meaning' (deep thoughts), and 'sensation' (thoughts about odors and sounds). LSD also increased free association for abstract words, reflecting an 'abstract flow.' Chaos was strongest from 2 to 6 hours after dosing, meaning from 2 to 4 hours, sensation at 2 hours, and abstract flow at 4 hours. The findings suggest a late therapeutic window around 4 hours for psycholytic therapy.
bioRxiv (Cold Spring Harbor Laboratory)
December 6, 2019
Felipe Augusto Cini da Silva, Isis M. Ornelas, Encarni Marcos et al.
9 citations
preprint
A single dose of d-LSD, a potent serotonergic agonist, increased preference for novel objects in young and adult rats several days after treatment, but did not increase preference in old animals unless followed by a 6-day exposure to enriched environment, which rescued novelty preference to young levels. Mass spectrometry-based proteomics in human brain organoids treated with d-LSD showed upregulation of proteins from the presynaptic active zone. A computational model of synaptic connectivity in the hippocampus and prefrontal cortex suggests that d-LSD enhances novelty preference by combining local synaptic changes in mnemonic and executive regions with alterations of long-range synapses, and that better pattern separation within enriched environment explains its synergy with d-LSD in rescuing novelty preference in old animals. These results advance the use of d-LSD in cognitive enhancement.
European Neuropsychopharmacology
September 1, 2009
D. Almeida Prado, Joel Porfírio Pinto, José Alexandre S. Crippa et al.
9 citations
Ayahuasca, a traditional Amazonian brew, shows promise in psychiatry, with 66% of participants reporting significant improvement in depressive symptoms after treatment. This study involved 100 individuals seeking relief from mental health issues. Participants experienced enhanced emotional well-being and altered perspectives on life, suggesting a blend of psychological and philosophical enlightenment. The findings highlight ayahuasca's potential as a medicinal tool within the broader context of psychedelics and drug studies, offering new insights into the intersection of psychology, art, and anthropology in understanding human experience.
The Journal of neuroscience : the official journal of the Society for Neuroscience
May 14, 2025
Çağatay Demirel, Jarrod Gott, Kristoffer Appel et al.
8 citations
Lucid dreaming, where a person becomes aware they are dreaming, is linked to REM sleep. To overcome previous research limitations, a new preprocessing pipeline was applied to pooled EEG data from multiple labs. Sensor-level differences between lucid and nonlucid REM sleep were minimal, but source-level analysis revealed reduced beta power (12-30 Hz) in right central and parietal areas, including the temporoparietal junction, during lucid dreaming. Alpha-band (8-12 Hz) connectivity increased compared to nonlucid REM sleep. During eye signaling of lucidity, gamma1 power (30-36 Hz) increased in right temporo-occipital regions, including the precuneus, and interhemispheric gamma1 connectivity rose. These patterns suggest shifts in network communication underlying changes in perception, self-awareness, and cognitive control.
Scientific reports
May 17, 2024
Annie C Souza, Bryan C Souza, Arthur França et al.
7 citations
The psychedelic 5-MeO-DMT alters brain activity in rats by increasing delta waves and decreasing theta waves in the hippocampus, changes that are not explained by movement. It also reduces slow and mid gamma power and disrupts theta phase modulation. The overall brain state resembles patterns seen during slow-wave sleep and REM sleep, suggesting that the drug's effects involve mixing waking behavior with sleep-like neural oscillations.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
March 1, 2023
Isabel Wießner, Marcelo Falchi, Dimitri Daldegan-Bueno et al.
6 citations
Low to moderate doses of LSD alter language structure, semantics, and vocabulary over time. In a double-blind, placebo-controlled crossover study, 24 healthy volunteers (age 35±11, 33% women) received 50 μg LSD or placebo. LSD reduced verbosity, lexicon, and connectivity in speech networks from 1.5 to 4 hours, decreased semantic distances between words from 2 to 24 hours, and shifted vocabulary related to grammar, persons, time, space, and biological processes from 1.5 to 24 hours. Simpler, disconnected structure and increased semantic similarity may reflect cognitive impairments, while vocabulary changes may indicate subjective perceptual shifts. Automated language analysis could offer unconstrained insights into psychedelic cognition.
bioRxiv Preprint Server
April 9, 2024
Çağatay Demirel, Jarrod Gott, Kristoffer Appel et al.
2 citations
preprint
Lucid dreaming, a state of conscious awareness during REM sleep, is associated with specific brain activity patterns. Compared to non-lucid REM sleep, EEG sensor-level differences were few. However, source-level analysis revealed increased gamma1 power (30-36 Hz) in left-hemispheric temporal areas during lucid dreaming, potentially reflecting verbal insight processes, and in right temporo-occipital regions including the precuneus around the onset of lucid eye signaling, linked to self-referential thinking. Beta power (12-30 Hz) decreased in right central and parietal areas including the temporo-parietal junction, possibly related to conscious reality assessment. Alpha-band (8-12 Hz) functional connectivity increased, contrasting with psychedelic states and highlighting enhanced self-awareness.
Scientific Reports
July 14, 2024
Annie C. Souza, Bryan C. Souza, Arthur França et al.
1 citation
No Summary
Jornal Brasileiro de Psiquiatria
January 1, 2024
Dráulio Barros de Araújo, Tiago Arruda Sanchez, Sidarta Ribeiro
1 citation
Psychedelic substances have been used by humanity for millennia to induce non-ordinary states of consciousness, characterized by heightened sensory, emotional, and cognitive experiences, including augmented visual imagery, altered perception of space-time and reality, and profound mystical insights. Many indigenous populations worldwide developed these substances as vital components of healing. In the Amazon, shamans ancestrally used Ayahuasca, a drink made from two plants, to promote physical and psychological healing. The Navajo in North America retain the ancestral use of the peyote cactus as sacred medicine, while the Mazatecs of Mexico used psilocybin-containing mushrooms in their healing rituals.
Journal of Psychedelic Studies
June 9, 2023
Beatriz Caiuby Labate, Anna O. Ermakova, Jordan Sloshower et al.
1 citation
The Drug Enforcement Administration's 2020 report on ayahuasca downplays the substance's safety and therapeutic potential while overemphasizing its risks, according to a critical analysis by scholars. The report omits current research demonstrating ayahuasca's potential benefits and contains factual omissions, theoretical biases, and misinterpretations of existing data. The critique was prompted by the DEA's 2023 disclosure of the report to the legal team of the Church of the Eagle and the Condor, following FOIA requests submitted two years earlier by the church and Chacruna Institute.
Ponto Urbe
December 27, 2024
Beatriz Caiuby Labate, Anna O. Ermakova, Jordan Sloshower et al.
In February 2023, the U.S. Drug Enforcement Administration (DEA) released a 2020 report titled 'Ayahuasca: Risks to Public Health and Safety' to the legal team of the Church of the Eagle and the Condor, following Freedom of Information Act requests. This article challenges several claims in the DEA report, highlighting factual omissions, theoretical biases, and misinterpretations of existing data. The authors argue that the report minimizes ayahuasca's safety profile and therapeutic potential while overemphasizing risks, and fails to include current research demonstrating its potential benefits.
bioRxiv (Cold Spring Harbor Laboratory)
June 5, 2023
Annie Da Costa Souza, Bryan Da Costa Souza, Arthur S. C. França et al.
preprint
The psychedelic 5-MeO-DMT increases delta power and decreases theta power in the hippocampus of freely moving rats, effects not explained by changes in locomotion. It also dose-dependently reduces slow and mid gamma power and theta phase modulation. The overall spectral profile of awake behavior after 5-MeO-DMT resembles electrophysiological states seen during slow-wave sleep and REM sleep. These findings suggest that classical psychedelics may integrate waking behaviors with sleep-like neural activity patterns.
bioRxiv (Cold Spring Harbor Laboratory)
February 13, 2017
Vanja Dakic, Juliana Nascimento, Rafaela Sartore et al.
preprint
5-MeO-DMT, a hallucinogenic molecule found in traditional Amerindian medicine, alters the proteome of human cerebral organoids. Of 6,728 identified proteins, 934 were differentially expressed after treatment. Systems biology analyses indicate anti-inflammatory effects and modulation of proteins linked to long-term potentiation, dendritic spine formation, cellular protrusion, microtubule dynamics, and cytoskeletal reorganization. These findings provide mechanistic insights into the neuropsychological changes associated with dimethyltryptamine ingestion.