November 15, 2022
Katie Zhou, D. de Wied, Robin Carhart‐Harris et al.
8 citations
preprint
About a third (32.7%) of people reported symptoms of hallucinogen persisting perception disorder (HPPD) four weeks after a real-world psychedelic experience, but only 2.94% found those symptoms distressing. Delusional ideation was slightly higher among those with more lifetime psychedelic use at baseline, yet it decreased significantly four weeks after the experience, suggesting the baseline correlation may not be causal. Younger age, female gender, a personality trait called absorption, less non-psychedelic substance use in the prior six months, and using psychedelics outside a retreat setting predicted HPPD-like symptoms. The findings are limited by the observational design.
Journal of psychoactive drugs
June 28, 2025
Laura C Carvalho, Jorge Encantado, Hannes Kettner et al.
6 citations
A review of 103 naturalistic psychedelic studies found that most used cross-sectional surveys, ayahuasca was the most studied substance (66%), and ceremonial settings were the most common context (35.9%). Sample characteristics were widely reported but varied considerably, while specific contextual details like music were often missing. The authors call for systematic reporting standards to improve the value of real-world psychedelic research alongside clinical trials.
Frontiers in Psychology
June 6, 2025
William Roseby, Hannes Kettner, Leor Roseman et al.
6 citations
Psychedelics like psilocybin strongly increase the sense that life has meaning, based on three different studies: a clinical trial for depression, a healthy volunteer study, and naturalistic retreats. The 'presence of meaning' rose substantially after a psychedelic experience, while the 'search for meaning' dropped only slightly. These meaning enhancements were moderately linked to improvements in mental health, such as greater wellbeing and reduced depression. Mystical, ego dissolution, and emotional breakthrough experiences were associated with increased meaning, though the strength varied by context. The evidence converges to show a robust, lasting positive effect of psychedelics on meaning in life, with context influencing outcomes.
Research square
March 8, 2024
Hannes Kettner, Leor Roseman, Adam Gazzaley et al.
5 citations
Older adults (age 60+) who participated in a guided psychedelic group retreat showed significant improvements in well-being, with larger gains among those with a prior psychiatric diagnosis. Compared to younger adults, older adults experienced weaker acute psychedelic effects, and these effects did not predict well-being changes. Instead, a sense of communitas—the relational or social connection during the group session—predicted well-being improvements in older adults, suggesting that the social context of psychedelic therapy may be especially important for this age group.
Brain and Behavior
July 1, 2025
Megan Calnan, Grace Blest‐hopley, Chris Busch et al.
4 citations
Military veterans who attended psilocybin or ayahuasca retreats showed significant improvements in eight measures of mental health and community reintegration, with the largest gains in depression (29.1% reduction on the PHQ-9) and PTSD (26.1% reduction on the PCL-5). Psilocybin retreats produced greater improvements on seven of eight outcomes, while ayahuasca retreats yielded slightly larger PTSD reductions (26.4% vs. 24.8%). Male participants improved more on all outcomes except PTSD, where females showed a larger reduction (32.1% vs. 24.1%). Veterans with worse initial symptoms benefited most. The findings suggest psychedelic retreats could offer a holistic treatment framework addressing psychological well-being, community factors, and civilian reintegration.
Current Psychiatry Reports
November 1, 2024
Matthew J Reid, Hannes Kettner, Tessa F Blanken et al.
4 citations
Psilocybin is an emerging treatment for depression, but its effects on sleep are not well understood. Clinical trials show large improvements in depressive symptoms, but sleep quality or insomnia symptoms have not been directly studied. Preliminary data indicate that both depressive symptoms and sleep disturbances decreased significantly after psilocybin use, though sleep improvements were smaller than those for depression. More severe sleep disturbances at baseline were linked to a lower probability of depression remission, suggesting a potential interaction between sleep and psilocybin's efficacy. Addressing sleep disturbances could enhance therapeutic outcomes and lead to more personalized treatment strategies.
bioRxiv : the preprint server for biology
August 12, 2024
Lorenzo Pasquini, Alexander J Simon, Courtney L Gallen et al.
4 citations
preprint
The psychedelic DMT rapidly alters consciousness, producing physical transcendence, vivid auditory distortions, and visual imagery. Using simultaneous fMRI and EKG data from 14 healthy volunteers before, during, and after intravenous DMT (versus placebo), a brain substate emerged immediately after injection characterized by deactivations in the hippocampus and medial parietal cortex alongside increased superior temporal lobe activity. Hippocampal and medial parietal deactivations correlated with disruptions in the sense of time, space, and self-referential processes, reflecting a deconstruction of ordinary consciousness. Superior temporal lobe activations correlated with audio/visual hallucinations and the experience of "entities.
Frontiers in Psychiatry
August 6, 2025
Grace Blest‐hopley, Giuseppe Pasculli, Simon Ruffell et al.
3 citations
Veterans with traumatic brain injuries who participated in psilocybin retreats showed improvements in PTSD, depression, and anxiety symptoms four weeks afterward. PTSD scores decreased by 50%, depression scores by 65%, and anxiety scores by 28%. Electroencephalography measurements revealed decreased delta and theta brainwave power in frontal and temporal regions, along with enhanced coherence in alpha and beta bands, suggesting improved cognitive control, emotional processing, and neural communication. The preliminary findings provide a rationale for larger controlled studies.
Research Square
August 22, 2025
Richard J. Zeifman, George Danias, Gabrielle Agin-Liebes et al.
2 citations
Psychedelics can acutely induce mystical experiences and elevated positive mood, which may contribute to the potential benefits of psychedelic therapy. However, there remains limited understanding of the occurrence and importance of specific positive emotional experiences within psychedelic therapy. Therefore, we examined the effects of psychedelics on positive emotional experiences and their association with improvements in mental health. Methods: Study 1 was an observational study of naturalistic psychedelic use. Study 2 used data from a clinical trial that compared psilocybin with escitalopram in individuals with major depressive disorder.
JMIR formative research
March 4, 2024
Grant Jones, Felipe Herrmann, Adam Bear et al.
2 citations
In a group of people who recently used psychedelics, increases in mindfulness were followed by improvements in well-being. The findings suggest that mindfulness may be a mechanism through which psychedelic experiences lead to positive mental health outcomes.
Sebastian Hübner, Eline Haijen, Mendel Kaelen et al.
2 citations
Younger age, lower educational levels, lower conscientiousness, and higher extraversion predict dropout in web-based prospective studies of psychedelic use. Baseline attitudes toward psychedelics and the intensity of acute challenging experiences do not predict attrition. These demographic and personality predictors align with those found in longitudinal research in other fields, suggesting that concerns about bias from psychedelic advocacy or negative drug experiences may be less problematic than previously thought.
Imaging Neuroscience
April 16, 2025
Lorenzo Pasquini, Alexander J. Simon, Courtney L. Gallen et al.
1 citation
DMT rapidly induces a short-lasting altered state of consciousness marked by physical transcendence, vivid auditory distortions, and visual imagery. Using simultaneous fMRI and EKG data from 14 healthy volunteers before, during, and after intravenous DMT or placebo, a brain substate emerged immediately after DMT injection, characterized by deactivations in the hippocampus and medial parietal cortex and increased activity in the superior temporal lobe. Hippocampal and medial parietal deactivations correlated with altered sense of time, space, and self-referential processes, reflecting a deconstruction of ordinary consciousness. Superior temporal lobe activations correlated with audio/visual hallucinations and the experience of "entities.
March 24, 2021
Pedro J. Teixeira, Matthew W. Johnson, Christopher Timmermann et al.
1 citation
preprint
Unhealthy behaviors like poor diet, inactivity, and smoking are major contributors to cancer, diabetes, and cardiovascular disease, causing substantial suffering and public health costs. Interventions to promote healthy behaviors increasingly draw on psychobiological models. This article explores the potential of psilocybin, a psychedelic with low toxicity and no addictive properties, to assist positive lifestyle change. Psilocybin has shown favorable effects in patients with depression, anxiety, and substance misuse, conditions marked by rigid behavioral patterns. The authors describe proposed mechanisms and research findings linking psychedelics to health behavior change, noting that therapeutic models combining psychedelic experiences with methods like Cognitive Behavior Therapy and Motivational Interviewing are already being tested for addiction and eating disorders. They suggest this research may extend to promoting diet, exercise, nature exposure, and mindfulness.
Journal of psychopharmacology (Oxford, England)
May 1, 2026
Otto Simonsson, Taylor Lyons, Joseph Marks et al.
Across three studies—a naturalistic observation, a single-arm psilocybin trial with healthy volunteers, and a randomized controlled trial comparing psilocybin to escitalopram in depressed patients—psychedelic use did not produce significant changes in authoritarian attitudes. Contrary to earlier suggestions, the evidence does not reliably show that psychedelics decrease authoritarian attitudes. Future work should use larger, more diverse samples and examine other political outcomes.
Behavioral Sciences
February 23, 2026
Joshua Lipson, Hannes Kettner, Robin Carhart-Harris et al.
Mood before taking a psychedelic substance and factors like social connectedness, mindfulness, and spirituality influence how the experience unfolds. People with higher baseline depression and anxiety tend to have more challenging experiences but not more mystical ones, while those with greater wellbeing report more mystical and fewer challenging experiences. Mindfulness and spirituality are linked to more mystical experiences, and social connectedness and mindfulness are linked to fewer challenging ones. Mystical and challenging experiences were weakly but positively correlated overall.
Journal of psychiatric research
November 1, 2025
Felipe M Herrmann, Grant Jones, Daniel M Low et al.
Increases in meaning in life, agreeableness, mindfulness, and extraversion are the psychological changes most strongly linked to future improvements in well-being after naturalistic psychedelic use. Increases in mindfulness, emotional stability, and extraversion are most associated with later reductions in anxiety, while increased self-esteem is most tied to decreased depression. Mindfulness was the only variable ranking among the top three predictors for all three outcomes—well-being, anxiety, and depression. These differing psychological changes may explain the mental health benefits observed after psychedelic use.
October 14, 2024
Terence J. Lyons, Merle Spriggs, Leevi Kerkelä et al.
preprint
A single high dose of psilocybin (25 mg) produced lasting functional and anatomical brain changes in healthy, psychedelic-naive adults, detected from one hour to one month later. Diffusion imaging showed decreased axial diffusivity in prefrontal-subcortical tracts, correlating with reduced brain network modularity, which in turn correlated with improved well-being. Increased cortical signal entropy shortly after dosing predicted better psychological well-being at one month, with next-day psychological insight mediating this relationship. No such effects occurred with a 1 mg placebo dose. Cognitive flexibility, psychological insight, and well-being also increased at one month.
Joe Hardy, Hannes Kettner, David Glowacki et al.
preprint
A group-based virtual reality program called Clear Light, delivered at home over three weeks, improved anxiety, depression, and wellbeing in people with life-threatening illnesses. The program included multi-user VR experiences, video calls, and text chats designed to elicit self-transcendent experiences similar to psychedelics. In a small observational study of 15 participants, moderate improvements were seen in anxiety, depression, wellbeing, demoralization, connectedness, and spiritual wellbeing. The intervention was well-tolerated. The findings suggest potential benefits but are limited by the lack of a comparison group, indicating the need for randomized controlled trials.
Grant Jones, Felipe Herrmann, Adam Bear et al.
Changes in mindfulness predict later changes in well-being among people who recently used psychedelics. The finding suggests that increases in mindfulness may lead to improvements in well-being in this population.
Psychedelic Medicine
December 15, 2025
M. Mehmood, Rebecka Bremler, M. Spriggs et al.
People who experienced more adverse childhood experiences (ACEs) showed greater improvements in mental well-being, reductions in experiential avoidance, and lower trait anxiety after participating in psychedelic ceremonies compared to those with fewer ACEs. Higher ACE scores were also linked to stronger emotional breakthrough and mystical experiences during the psychedelic session. Among individuals with four or more ACEs, those who reported stronger mystical or emotional breakthrough experiences had better well-being at two and four weeks afterward, and mystical experiences were linked to less experiential avoidance while emotional breakthrough was linked to less anxiety at four weeks. However, the acute experiences did not significantly change how ACEs affected mental health outcomes overall.