Scientific reports
February 10, 2020
Frederick S Barrett, Manoj K Doss, Nathan D Sepeda et al.
375 citations
A single 25 mg/70 kg dose of psilocybin temporarily reduced negative affect and amygdala response to negative facial expressions one week later in twelve healthy volunteers, while positive affect and prefrontal cortex responses to emotional conflict increased. One month later, negative affect and amygdala reactivity returned to baseline, but positive affect remained elevated and trait anxiety was lower. The number of resting-state functional connections across the brain increased from baseline to both one week and one month after dosing. These preliminary findings suggest psilocybin may enhance emotional and brain plasticity, with negative affect as a potential therapeutic target.
Scientific reports
November 23, 2021
Christopher Timmermann, Hannes Kettner, Chris Letheby et al.
208 citations
People who use psychedelic drugs often shift away from materialist views of reality and consciousness toward panpsychism and fatalism, with most changes lasting at least six months. In a large prospective online survey, these belief shifts correlated with greater past psychedelic use and improved mental health. Emotional synchrony with others during the experience mediated the changes, and baseline impressionability moderated them. An independent clinical trial confirmed the direction of belief change, suggesting psychedelics may causally influence metaphysical beliefs away from hard materialism, though contextual independence remains uncertain.
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.
Scientific reports
June 27, 2019
Jon G Dean, Tiecheng Liu, Sean Huff et al.
111 citations
The psychedelic compound N,N-dimethyltryptamine (DMT) is produced naturally in mammals, but whether it is made in the brain was unclear. This study found that the enzymes needed to synthesize DMT are present in the cerebral cortex, pineal gland, and choroid plexus of both rats and humans. In rat brain tissues, the two key enzymes were found together, unlike in peripheral tissues. DMT concentrations in the cerebral cortex of behaving rats were similar to those of neurotransmitters like serotonin. DMT levels in the visual cortex rose significantly after cardiac arrest, even without the pineal gland. These findings indicate the rat brain can synthesize and release DMT at neurotransmitter-like levels, suggesting human brains might do the same.
Scientific reports
May 24, 2022
David Wyndham Lawrence, Robin Carhart-Harris, Roland Griffiths et al.
64 citations
An analysis of over 3,700 naturalistic experiences with inhaled N,N-DMT posted to Reddit over a decade reveals common themes. Somatic effects like body sensations (37.5%) and auditory ringing (15.4%) were frequent, while visualizations often involved fractals, shapes, and vivid colors. Entity encounters occurred in 45.5% of experiences, most commonly with a feminine phenotype, deities, aliens, and creature-based beings. Interactions were predominantly positive or pedagogical. Descriptions of alternate dimensions, rooms including a 'waiting room,' and tunnels were common. Mystical and ego-dissolution features were frequent, along with rewarding aspects like reduced fear of death. Challenging responses were less common.
Scientific reports
May 22, 2023
Teresa Fazia, Francesco Bubbico, Andrea Nova et al.
62 citations
A mindfulness-based program combining meditation, dietary advice, and yoga reduced stress and improved well-being, emotional regulation, resilience, and attention among medical students. In a randomized trial with 362 Italian medical students, those who participated in the 10-session intervention showed significantly lower perceived stress, less mind-wandering, and better emotional regulation compared to controls. The program also enhanced mental well-being, resilience, and attentional control, while reducing overall distress. These results suggest that such integrative interventions can help mitigate the psychological strain common in medical education.
Scientific reports
April 17, 2024
Jordan Sloshower, Richard J Zeifman, Jeffrey Guss et al.
56 citations
Psilocybin-assisted therapy improves psychological flexibility, mindfulness, and values-congruent living in people with moderate to severe major depressive disorder, and these improvements are strongly linked to reductions in depression severity. In an exploratory placebo-controlled study, participants received placebo then psilocybin (0.3 mg/kg) four weeks later, with dosing sessions embedded in Acceptance and Commitment Therapy. Psychological flexibility, several facets of mindfulness, and values-congruent living significantly improved after psilocybin and were maintained through week 16. The findings suggest that increasing psychological flexibility may be a key mechanism underlying psilocybin's therapeutic effects.
Scientific reports
April 17, 2023
Rubén Herzog, Pedro A M Mediano, Fernando E Rosas et al.
51 citations
Psychedelic drugs such as LSD, which activate the serotonin 2A receptor, produce profound changes in consciousness and are linked to increased entropy in spontaneous brain activity. This study provides the first model-based explanation for that entropy increase by extending a whole-brain model of serotonin neuromodulation. The model reproduced the overall rise in neural entropy seen in prior experiments. Entropy increased across all brain regions, with the largest effects in visuo-occipital areas. At the whole-brain level, this reconfiguration was not well explained by the density of serotonin 2A receptors but was closely related to the topological properties of the brain's anatomical connectivity.
Scientific reports
October 10, 2022
Grant M. Jones, Matthew K. Nock
46 citations
Lifetime use of MDMA or psilocybin is associated with lower odds of psychological distress and suicidality among White individuals, but these protective associations are far fewer for racial and ethnic minorities. Analyzing data from over 484,000 participants in the National Survey on Drug Use and Health (2008–2019), race and ethnicity significantly moderated the links between psychedelic use and mental health outcomes. The findings highlight the need for further research on how identity factors such as race, ethnicity, socioeconomic status, and sexual/gender minority status influence the effects of psychedelic substances.
Scientific reports
January 9, 2025
Efrem Fenta, Diriba Teshome, Simegnew Kibret et al.
36 citations
In a study conducted in Ethiopian hospitals, 41% of patients developed postoperative delirium after surgery. Patients aged 75 or older were 11 times more likely to experience delirium, and those with severe functional impairment or premedication with benzodiazepine also had higher odds. Other risk factors included ASA-PS IV status, intraoperative blood loss over 1000 ml, and intraoperative ketamine use. Delirium prolonged both post-anesthesia care unit and hospital stays.
Scientific reports
October 1, 2019
Charlotte Martial, Armand Mensen, Vanessa Charland-Verville et al.
36 citations
A proof-of-concept study induced near-death experience (NDE)-like features in five volunteers who had previously had a pleasant NDE by having them recall the memory under hypnosis while their brain activity was recorded with high-density EEG. The hypnosis protocol recreated NDE-like features without adverse effects and increased absorption and dissociation compared to normal consciousness recall. Recalling the NDE phenomenology was associated with increased alpha brain activity in frontal and posterior regions. The methodology offers a controlled way to prospectively study NDE-like features and their EEG correlates.
Scientific reports
June 9, 2023
Brandon Weiss, Aleksandra Wingert, David Erritzoe et al.
32 citations
Ayahuasca ceremonies commonly trigger reexperiencing of adverse life events, with women more likely to reexperience sexual assault, veterans more likely to reexperience combat trauma, and individuals with PTSD showing higher prevalence of reexperiencing. Reexperiencing was associated with cognitive reappraisal, psychological flexibility, and discomfort during ceremonies. Participants who reexperienced adverse events showed greater reductions in trait neuroticism after ceremonies. The study tracked 33 military veterans and 306 non-veterans across three timepoints at ayahuasca centers in South and Central America.
Scientific reports
January 29, 2025
Richard J Zeifman, Meg J Spriggs, Hannes Kettner et al.
26 citations
A preliminary test of the REBUS model found that a high dose of psilocybin (25 mg) reduced confidence in negative self-beliefs in 11 healthy individuals, both during the acute experience and four weeks later. Greater brain signal entropy and stronger subjective effects under psilocybin correlated with larger decreases in negative self-belief confidence. Decreases in negative self-belief confidence were linked to increases in well-being. The findings provide initial evidence that relaxing and revising negative self-beliefs may underlie psilocybin's positive psychological effects, with increased neuronal entropy as a possible mechanism. Replication in larger clinical samples is needed.
Scientific reports
November 24, 2023
Robert Palmer, Corey Roos, Nilofar Vafaie et al.
26 citations
A single session of mindfulness meditation, whether 10 or 20 minutes, increases state mindfulness more than listening to a National Geographic article. The 10-minute meditation produced a greater increase in state mindfulness than its control, but there was no difference between the 10- and 20-minute meditation groups. People with lower trait mindfulness benefited more from meditation versus control in terms of state mindfulness. Among those with high trait mindfulness, the 20-minute meditation led to greater reductions in state anxiety than the 10-minute one. Overall, dose-response effects were minimal, suggesting 10 and 20 minutes of meditation improve state mindfulness comparably.
Scientific reports
March 27, 2024
Alyssa Torske, Benno Bremer, Britta Karen Hölzel et al.
24 citations
A 31-day web-based mindfulness meditation training, compared to a health training condition, increased mindfulness and reduced stress-eating, emotional-eating tendencies, and food cravings in 66 meditation-naïve adults who tend to stress-eat. These behavioral improvements were accompanied by changes in resting-state functional connectivity between the hypothalamus, reward regions, and default mode network areas, as well as between the insula and somatosensory areas. Additional connectivity changes occurred in brain regions linked to emotion regulation, awareness, attention, and sensory integration. The correlations between connectivity and behavioral changes suggest neural mechanisms underlying mindfulness effects on stress-eating.
Scientific reports
February 8, 2024
Rosalind G McAlpine, George Blackburne, Sunjeev K Kamboj
24 citations
A new 20-item Psychedelic Preparedness Scale (PPS) was developed and validated to measure how well participants are prepared for psychedelic experiences. Using an iterative Delphi-focus group method and input from clinicians, researchers, and psychedelic users, the scale identifies four factors: Knowledge-Expectations, Intention-Preparation, Psychophysical-Readiness, and Support-Planning. In two large online samples (N = 516 and N = 716) and a psilocybin retreat group (N = 46), the PPS showed excellent reliability and evidence for convergent, divergent, and discriminant validity. People scoring higher on preparedness before a psychedelic experience had better mental health and wellbeing outcomes afterward, indicating the scale can predict who may benefit or be less likely to experience harm.
Scientific reports
July 17, 2024
Sara de la Salle, Hannes Kettner, Julien Thibault Lévesque et al.
21 citations
A prospective longitudinal survey of eight Canadians with cancer who received legal psilocybin-assisted psychotherapy under Section 56 exemptions found significant improvements in anxiety, depression, pain, fear of COVID-19, quality of life, and spiritual well-being two weeks after the session. Attitudes toward death, medical assistance in dying, and desire for hastened death remained unchanged. Most participants found the sessions highly meaningful, though one reported a substantial decrease in well-being. These preliminary data suggest that real-world psilocybin-assisted psychotherapy can produce psychiatric benefits similar to those in clinical trials, but limited enrollment and negative experiences indicate a need for formal real-world evaluation programs.
Scientific reports
June 5, 2024
Suruchi Fialoke, Vaibhav Tripathi, Sonika Thakral et al.
21 citations
During yoga nidra, a practice that aims for deep relaxation with heightened awareness, experienced meditators show reduced connectivity within the default mode network (DMN) compared to novices, as measured by fMRI. This decoupling of DMN regions was not present during ordinary resting states before or after the practice. The degree of reduced DMN connectivity correlated with the participants' cumulative hours of meditation and yoga experience. The findings suggest that yoga nidra produces a distinct neural state in experienced practitioners, supporting their subjective experience of being restful yet aware, and offer insight into the neural mechanisms underlying the practice.
Scientific reports
December 19, 2023
María Guadalupe Mora Álvarez, Britta Karen Hölzel, Benno Bremer et al.
19 citations
A 31-day web-based mindfulness meditation training reduced perceived stress and anxiety and improved overall reaction time on an attention test, though no specific attentional components were affected. The training also increased flow experiences. Brain imaging showed increased activity in the superior frontal gyrus, posterior cingulate cortex, and right hippocampus during an alerting task, and decreased stress and anxiety correlated with right hippocampus activation. Increased flow correlated with activity in all those areas. Diffusion imaging revealed improved white matter microstructure in the right uncinate fasciculus, linking the right hippocampus to frontal areas. An active control group showed no significant changes.
Scientific reports
July 19, 2023
Adelaida Castillo, Julien Dubois, Ryan M Field et al.
19 citations
Ketamine administration in healthy participants caused an altered state of consciousness and changes in systemic physiology, including increased pulse rate and electrodermal activity. The drug led to a brain-wide reduction in the fractional amplitude of low frequency fluctuations and decreased global brain connectivity in the prefrontal region. Preliminary evidence suggests that a combination of neural and physiological metrics may predict subjective mystical experiences and reductions in depressive symptoms. The study demonstrates the successful use of fNIRS neuroimaging to measure physiological effects of ketamine in a clinical setting, representing a step toward larger clinical fNIRS studies of psychedelics.
Scientific reports
November 14, 2024
Erin Wang, David S Mathai, Natalie Gukasyan et al.
18 citations
Among 879 U.S. healthcare professionals surveyed online, most endorsed strong belief in the therapeutic promise of psychedelic-assisted therapy with psilocybin and MDMA, and showed moderate openness to clinical use and support for legal access, with higher ratings for psilocybin than MDMA. However, objective knowledge of therapeutic uses, risks, and pharmacology was low. Primary concerns included lack of trained providers, financial cost, and potential contraindications. Prior psychedelic use, self-rated knowledge, younger age, and professional role predicted greater openness, while physicians reported lower openness. Results indicate a pressing need for formal training to provide balanced, evidence-based information.
Scientific reports
December 19, 2022
Grant Jones, Diego Arias, Matthew Nock
18 citations
Lifetime psilocybin use among U.S. adolescents aged 12-17 was associated with 15-23% lower odds of suicidal thinking, planning, and attempts, while LSD use was linked to 20-35% higher odds of these same outcomes. MDMA/ecstasy, peyote, and mescaline showed no significant associations with suicidal thoughts or behaviors. These findings come from a nationally representative sample of 262,617 adolescents surveyed between 2004 and 2019. The results suggest that individual classic psychedelics have distinct relationships with adolescent suicide risk, highlighting the need for further research to clarify these links.
Scientific reports
January 6, 2023
Nicolas G Glynos, Lily Carter, Soo Jung Lee et al.
17 citations
Indolethylamine N-methyltransferase (INMT) is an enzyme known for producing the psychedelic compound DMT in mammalian brains. Researchers created INMT-knockout rats to determine whether INMT is necessary for DMT production. Brain and lung tissues from both normal and INMT-knockout rats showed equal levels of tryptamine-dependent activity, but the resulting products were neither NMT nor DMT. Rat INMT alone was also insufficient for producing NMT or DMT. These findings indicate an alternative enzymatic pathway for DMT biosynthesis exists in rats, motivating further investigation into how mammals produce DMT naturally.
Scientific reports
June 7, 2021
Evan Houldin, Zhuo Fang, Laura B Ray et al.
17 citations
During sleep, functional connections between brain networks shift in a directional manner. In non-REM (NREM) sleep, positive wake-like correlations often become negative and strengthen in the opposite direction, while in REM sleep they trend back toward positive correlations. This pattern supports the idea that NREM sleep involves altered, not merely reduced, functional connectivity. Many of these connections involve higher-order networks linked to cognition and consciousness, such as the default mode network, suggesting possible accompanying changes in cognitive and conscious states.
Scientific reports
May 3, 2024
David K Sjöström, Emma Claesdotter-Knutsson, Petri J Kajonius
16 citations
Swedish adults who have used psychedelics at least once report less depression than non-users who are the same sex and age, but also report more drug use. The difference in depression is partly explained by lower neuroticism among users. Psychedelic users also score much higher on openness to experience, a personality trait. The findings come from a national online survey comparing 400 psychedelic users with 400 matched non-users.