bioRxiv (Cold Spring Harbor Laboratory)
March 11, 2025
Devon Stoliker, Leonardo Novelli, Moein Khajehnejad et al.
8 citations
preprint
Psychedelics like psilocybin alter consciousness by reorganizing brain connectivity in a context-sensitive way. In the largest psychedelic neuroimaging dataset to date, 62 adults underwent functional MRI and EEG before and after ingesting 19 mg of psilocybin, during rest and naturalistic stimuli. Under psilocybin, brain signals during eyes-closed conditions became similar to those during eyes-open conditions, with increased global functional connectivity in associative regions and decreased connectivity in sensory areas. Machine learning linked subjective effects to structured neural activity patterns. Stronger self-dissolving effects were associated with more distinct neural representations and next-day mindset changes, revealing a state of 'embeddedness' where networks that usually segregate internal and external processing integrate coherently, aligning neural dynamics with context.
Psychedelic medicine (New Rochelle, N.Y.)
June 1, 2025
Haley Maria Dourron, Melissa Bradley, Otto Simonsson et al.
7 citations
Greater lifetime psychedelic use was not associated with psychotic symptoms in a cross-sectional survey of 548 adults, even among those with a personal or family history of psychotic or bipolar disorders. In unadjusted analyses, more psychedelic use was linked to less referential thinking, but this association disappeared after adjusting for covariates. A personal history of psychotic disorders was tied to moderately greater magical ideation, referential thinking, and auditory hallucinations, while family history of psychotic disorders related to slightly greater negative symptoms. Notably, among individuals with a personal history of psychotic disorder, auditory hallucinations were less severe as psychedelic use increased, with no such relationship in those without that history. Naturalistic psychedelic use may not heighten psychosis risks.
Mindfulness
May 29, 2023
Otto Simonsson, Christine Bergljottsdotter, Jayanth Narayanan et al.
7 citations
Mindfulness training helped British politicians better cope with the demands and stresses of political work, reconnect with themselves, and relate to other politicians more constructively, especially in group settings. Interviews with 18 politicians and 4 mindfulness facilitators revealed two main themes: mindfulness approaches addressing particular challenges in political work, and the role of group dynamics in training. The findings suggest mindfulness can be beneficial personally and professionally for those in political contexts, supporting the case for government mindfulness programs.
Journal of Psychopharmacology
October 1, 2022
Grant Jones, Jocelyn A. Ricard, Peter S. Hendricks et al.
7 citations
Lifetime use of MDMA (ecstasy) is associated with better self-reported physical health, including lower risks of overweight/obesity, heart conditions, cancer, hypertension, and diabetes, along with higher odds of reporting good overall health. These associations emerged from a large, nationally representative U.S. sample, controlling for potential confounders. The findings suggest protective links between ecstasy use and various physical health markers, but the authors call for longitudinal studies and clinical trials to confirm causality.
Frontiers in psychiatry
January 1, 2022
Otto Simonsson, José Carlos Bouso, Florian Kurth et al.
6 citations
The corpus callosum, a brain structure connecting the two hemispheres, was thicker in the isthmus region among 22 ayahuasca users compared to 22 matched controls. A positive correlation was observed between callosal thickness in the rostral body and the number of past ayahuasca sessions, though neither finding survived correction for multiple comparisons. No brain region was thicker in controls than in ayahuasca users, and no region was negatively linked to ayahuasca use. This provides preliminary evidence of an association between ayahuasca use and callosal structure, but replication with larger samples and longitudinal designs is needed.
JAMA Network Open
May 7, 2026
Peter S. Hendricks, Sara Lappan, Richard C. Shelton et al.
4 citations
A single 25 mg dose of psilocybin, combined with psychotherapy, led to a higher percentage of cocaine-abstinent days, a greater likelihood of complete abstinence, and a longer time before the first cocaine lapse over 180 days compared with an active placebo (100 mg diphenhydramine) in a randomized, quadruple-blind trial. Among 40 participants with cocaine use disorder, 33 were men, 33 were Black, and most had low income. Psilocybin appeared safe, with no serious adverse events, and may offer a treatment for cocaine use disorder in underrepresented populations.
J Psychopharmacol
October 29, 2024
Otto Simonsson, Simon B Goldberg, Peter S Hendricks
4 citations
Psychedelic-assisted therapies are gaining attention as potential treatments for mental health conditions, but their safety profile remains incompletely understood. This article maps the landscape of adverse events that can occur during such therapies, including psychological distress, physiological reactions, and challenging experiences. The authors argue that a systematic framework is needed to categorize and manage these events, drawing on clinical reports and existing literature. They emphasize that while serious adverse events appear rare, mild to moderate reactions are common and require careful protocol design and therapist training. The piece calls for standardized reporting to improve safety monitoring and clinical outcomes in this emerging field.
Frontiers in psychology
January 1, 2023
Otto Simonsson, Cecilia U D Stenfors, Simon B Goldberg et al.
4 citations
Mindfulness meditation and psychedelic use are both associated with positive impacts on leadership, though through different mechanisms. In a representative sample of 3,150 managers in the US and UK, more lifetime hours of mindfulness meditation and greater psychological insight during the most intense psychedelic experience each independently predicted a positive leadership impact (odds ratios 2.33 and 3.49, respectively). Both practices shared subthemes such as improved focus, creativity, patience, empathy, and compassion. Unique to mindfulness were better sleep, stress reduction, and calming effects; unique to psychedelics were greater self-understanding, less hierarchical attitudes, and positive interpersonal changes. The cross-sectional design precludes causal conclusions, but the findings suggest complementary benefits for leadership development.
Journal of psychopharmacology (Oxford, England)
March 12, 2025
Zusanna Bjurenfalk, Alva Cosmo, Otto Simonsson et al.
3 citations
People who had ever used classic psychedelics such as LSD or psilocybin showed 25% lower odds of reporting frequent bad headaches, based on data from over 11,000 British adults. The analysis controlled for many other factors, suggesting a possible protective association. This finding adds to evidence that classic psychedelics might one day be developed as preventive treatments for migraine and cluster headache, though the study cannot prove cause and effect.
medRxiv
August 28, 2024
Zishan Jiwani, Simon B. Goldberg, Jack Stroud et al.
3 citations
preprint
Most meditators who use psychedelics perceive them as beneficial for their meditation practice. Among 863 regular meditators (practicing at least three times weekly for the past year) who also used psychedelics, machine learning identified four factors most likely to predict this positive perception: greater frequency of psychedelic use, setting intentions before use, higher agreeableness, and having used N,N-Dimethyltryptamine (DMT). The model explained about 27% of the variance. The findings suggest that intentional and personality factors may shape how psychedelics influence meditation, but causality remains unestablished.
Int J Drug Policy
December 13, 2025
Michelle Olofsson, Walter Osika, Simon B. Goldberg et al.
2 citations
A cross-sectional survey of 3,168 U.S. adults with lifetime psychedelic use found that most (87.9%) reported no difficulties. Among those who did, 6.4% experienced post-acute difficulties lasting more than one day, and 1.3% for more than one year. The most common difficulties were general anxiety, negative changes in self-concept, and social disconnection. Childhood adversity was associated with higher odds of psychedelic-related difficulties: individuals with 2, 3, or 4 or more adverse childhood experiences had roughly double to nearly triple the odds of difficulties compared to those with none. Those with 4 or more ACEs also had higher odds of difficulties persisting beyond one day or one week.
J Psychiatr Res
March 17, 2025
Otto Simonsson, Sankalp Chaturvedi, Peter S. Hendricks et al.
2 citations
Psychedelic use is linked to increases in weekly mindfulness and loving-kindness or compassion meditation practice, especially among people new to psychedelics or meditation. In a longitudinal study of 13,012 US adults aged 18–50, with 7,484 completing follow-up and 336 reporting psychedelic use during the two-month study, those who used psychedelics showed greater gains in meditation days. Among psychedelic users, higher baseline trait mindfulness and self-compassion predicted less severe challenging experiences and lower odds of psychedelic-related thoughts or attempts of self- or other-harm. However, for those already meditating, psychedelic use was associated with more meditation-related difficulties and impairments.
PLoS ONE
May 13, 2024
Otto Simonsson, Stephen D. Fisher
2 citations
In 2021, 16 percent of adults in Britain had learned to practice mindfulness. Among those who practiced during the COVID-19 pandemic, 60 percent reported positive mental health effects, while 24 percent reported negative effects. Negative effects were more common among respondents with children under 18 (41 percent) compared to those without minors (13 percent). Mindfulness practice was more common among young and middle-aged adults, London residents, and Liberal Democrat voters. The findings indicate that mindfulness use is widespread but concentrated in certain groups, and that negative mental health effects affect a notable minority, warranting further research.
February 19, 2023
Kevin M. Riordan, Otto Simonsson, Corrina Frye et al.
2 citations
preprint
A two-week compassion-based meditation intervention delivered via the Healthy Minds Program app led to improvements in psychological distress, experiential avoidance, fear of missing out, loneliness, and self-compassion among undergraduates with clinically elevated depression and/or anxiety. Participants were randomized to either one 20-minute meditation per day (Massed condition) or two 10-minute meditations per day (Distributed condition). Both groups showed similar improvements, with no significant differences between conditions on any outcome. When total daily meditation time is held constant, distributing practice across the day does not appear to influence outcomes for distressed beginners, supporting flexibility in meditation scheduling.
February 10, 2023
Qiang Xie, Kevin M. Riordan, Scott A. Baldwin et al.
2 citations
preprint
Among clinically distressed adults with no meditation experience who used a smartphone-based loving-kindness and compassion training program for two weeks, those who increased their informal meditation practice (using techniques outside formal sessions) showed greater reductions in psychological distress and loneliness from before to after the intervention, though no changes in empathy or prosociality were observed. Daily analyses indicated that more informal practice on a given day predicted lower distress the next day, but not lower loneliness. Distress and loneliness did not predict subsequent informal practice. The findings suggest that informal practice may play a causal role in reducing distress, but further experimental studies are needed.
PLoS One
February 12, 2025
Zishan Jiwani, Simon B. Goldberg, Jack Stroud et al.
1 citation
Most meditators who also use psychedelics report that the drugs improve their meditation practice. In a survey of 863 regular meditators who had used psychedelics, 73.5% said psychedelics positively influenced the quality of their meditation. Machine learning analysis of 53 variables identified the strongest predictors of this perceived benefit: greater frequency of psychedelic use, setting intentions before taking psychedelics, having an agreeable personality, and having used N,N-Dimethyltryptamine (N,N-DMT). The results suggest that individual traits and patterns of use shape whether psychedelics are seen as helpful for meditation, but causality cannot be established from this cross-sectional data.
The Journal of rural health : official journal of the American Rural Health Association and the National Rural Health Care Association
January 1, 2025
Melissa Bradley, Daniel Grossman, Otto Simonsson et al.
1 citation
Rural residents in the United States are 1.2 to 1.4 times more likely than urban residents to perceive using LSD once or twice as of great risk, based on national survey data from 2015 to 2021. The perception of monthly cannabis use as having great risk was slightly higher among rural residents only until 2019, with no significant differences in 2020 and 2021. These rural-urban differences in risk perception could influence policymaking on psychedelic therapies and highlight the need for equitable policies.
Psychedelic Medicine
June 22, 2026
Otto Simonsson, Peter S. Hendricks, Walter Osika et al.
Naturalistic psychedelic use on politically salient dates like the Fourth of July may shift support for partisan violence in directions tied to the event's political meaning. In a longitudinal observational study of 21,990 US adults, 12,345 completed follow-up surveys; 505 reported psychedelic use during the two-month period. Those whose most intense psychedelic experience occurred on the Fourth of July showed decreased support for partisan violence, with a similar pattern for the Trump assassination attempt date. Conversely, experiences on national party convention dates or closer to Election Day were associated with increased support for partisan violence. The broader sociocultural context appears to modulate these outcomes.
JMIR Mental Health
June 12, 2026
Polina Beloborodova, Lillian M. Smith, Kevin M. Riordan et al.
About 28% of distressed college students and 10% of distressed US adults reported at least one adverse experience during a digital meditation program, but rates did not differ between those who completed guided meditations and those who did not, suggesting the experiences were not caused by meditation itself. Higher baseline depression, anxiety, loneliness, experiential avoidance, and perceived barriers to meditation predicted more adverse experiences. Among those reporting adverse experiences, roughly 90% were glad to have learned to meditate. Participants used diverse coping strategies, often drawing on skills taught in the program. The findings indicate that adverse experiences during meditation training may reflect preexisting distress rather than iatrogenic harm.
Research square
May 19, 2026
Sunjuri Sun, Claudia Hanson, Peter S Hendricks et al.
The evidence on child and maternal outcomes after exposure to classic psychedelics during pregnancy is very sparse and of very low certainty. A systematic review of 42 studies, mostly case reports from high-income countries, found that LSD was the most commonly reported substance. Outcomes reported included spontaneous abortions (2 studies), stillbirth (1 study), neonatal mortality (16 studies), preterm birth (17 studies), birthweight (15 studies), and congenital malformations (26 studies). No maternal deaths were reported. Because of small sample sizes and varied study designs, no meta-analysis was possible. The authors conclude that methodologically rigorous research on psychedelic use during pregnancy is urgently needed.
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.
Journal of psychopharmacology (Oxford, England)
May 1, 2026
Otto Simonsson, Sunjuri Sun, Laura W Wesseldijk et al.
In a large twin study using the Swedish Twin Registry, people who reported using psychedelics had lower odds of having a history of migraine. Among identical twins, the twin who used psychedelics was less likely to have migraine than their co-twin who did not. The association was significant in males but not in females. These results suggest a possible link between psychedelic use and reduced migraine likelihood, with sex differences that need further study.
Scientific Reports
February 10, 2026
Michelle Olofsson, Kasim Acar, Otto Simonsson et al.
Lifetime MDMA use was not significantly associated with meaning in life overall, but a significant interaction emerged: among Swedish adults with a history of childhood trauma, those who had ever used MDMA reported higher meaning in life than those who had not. Meaning in life was measured using the presence subscale of the Meaning in Life Questionnaire. The findings suggest MDMA use may relate to psychological resilience in trauma-exposed populations, though further longitudinal and experimental research is needed to test causal direction.
Scientific Reports
January 28, 2026
Nicholas A. Carlisle, Otto Simonsson, Sarah Maccarthy et al.
About one in five people who have used psychedelics report at least one major life change they attribute to the experience. Common changes involve relationships (6.9%), diet and exercise (6.2%), quitting alcohol, tobacco, or other substances (5.5%), and religious beliefs (5.5%). In a larger, more diverse sample, higher religiosity, younger age, and greater lifetime psychedelic use were strongly associated with reporting such changes. The findings suggest that major life changes after psychedelic use are not rare and may vary by demographic factors, but more longitudinal research is needed to understand their persistence, valence, and health impact.
Journal of psychopharmacology (Oxford, England)
January 1, 2024
Otto Simonsson, Peter S Hendricks, Cecilia Ud Stenfors et al.
A longitudinal study with nearly 10,000 US and UK adults found that people who used psychedelics during a two-month period reported greater increases in unusual visual experiences compared to those who did not. The effect was strongest among first-time users. These visual experiences occurred after the acute drug effects had worn off. The findings support earlier case reports and cross-sectional studies suggesting that naturalistic psychedelic use may be linked to persistent visual phenomena, though further longitudinal research is needed to clarify cause-and-effect relationships.