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Leor Roseman

Imperial College London, Multidisciplinary Association for Psychedelic Studies

117 papers in the library · 11,495 citations · publishing 2014-2026

Papers

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How to set up a psychedelic study: Unique considerations for research involving human participants.

Neuroscience and Biobehavioral Reviews July 1, 2026 Marcus J. Glennon, Catherine Bird, Prateek Yadav et al. 2 citations

Setting up a psychedelic study can be a long, arduous, and Kafkaesque process. Researchers are faced with a host of challenges in this rapidly evolving field, necessitating a range of considerations that remain largely unstandardised. Many of the complexities inherent to psychedelic research also challenge existing assumptions around, for example, approaches to psychiatric prescribing, the...

Micro-Messiahs and the Revolutionary Dynamics of Psychedelic Diffusion

Religions June 24, 2026 Leor Roseman

Prophetic or messianic states of consciousness are charged with moral urgency and are active, historical, political, and sometimes infused with ego. In this paper, I inquire into psychedelic micro-messianic phenomenology and revolutionary dynamics through the historical case studies of Allen Ginsberg, Master Irineu, and John Wilson (Moonhead)—figures associated with the diffusion of LSD, Daime...

Koshering Psychedelics: Ayahuasca in the Ultra-Orthodox (Haredi) Jewish World

June 21, 2026 Jonathan David, Aviva Berkovich-Ohana, Yair Dor-Ziderman et al. preprint

Background: Despite the rapid growth of psychedelic research, limited attention has been given to how psychedelics are used, experienced and integrated within highly conservative religious communities, and in Jewish contexts more broadly. This study addresses this gap by examining ayahuasca use among the ultra-Orthodox (Haredi) community, a highly religious, conservative, and collectivist...

Human brain changes after first psilocybin use.

Nature Communications May 5, 2026 T Lyons, M Spriggs, L Kerkelä et al. 19 citations

Psychedelics have robust effects on acute brain function and long-term behavior but whether they also cause enduring functional and anatomical brain changes is largely unknown. In an exploratory, placebo-controlled, within-subjects, electroencephalography (EEG), and magnetic resonance imaging (MRI) study in 28 healthy, entirely psychedelic-naive participants, anatomical and functional brain...

Effects of psychedelic use on authoritarian attitudes revisited.

Journal of psychopharmacology (Oxford, England) May 1, 2026 Otto Simonsson, Taylor Lyons, Joseph Marks et al.

Previous research suggests that psychedelics may, under certain conditions, decrease authoritarian attitudes, but larger and more rigorously designed studies are needed to confirm these findings. We aimed to examine the effects of psychedelic use on authoritarian attitudes. Using data from three separate studies with different designs and populations, we investigated the relationship between...

An international mega-analysis of psychedelic drug effects on brain circuit function

Nature Medicine April 1, 2026 Manesh Girn, Manoj K. Doss, Leor Roseman et al. 8 citations

Psychedelic drugs are re-emerging as promising scientific and clinical tools. However, despite a rapidly expanding literature on their therapeutic value, the neural mechanisms underlying psychedelic effects remain unclear. Resting-state functional magnetic resonance imaging studies of acute psychedelic effects, conducted independently by several research groups, have so far yielded fragmented...

Towards social curative psychedelic treatment

Discover Mental Health March 21, 2026 Martha Newson, Leor Roseman, S. Alexander Haslam

Recent advances in psychedelic-assisted therapies highlight their efficacy in treating various mental health conditions. Nevertheless, the fact that delivery is generally individualised may limit therapeutic outcomes by failing to capitalise on opportunities to build and harness a sense of shared social identity among participants in ways hypothesised by ‘social cure’ research. In line with...

Learning from boundlessness: epistemic shifts towards a holistic worldview following psychedelic experiences

npj Mental Health Research January 29, 2026 Eirini K. Argyri, Flora Fraser, Stefan Schilling et al.

Psychedelic substances are increasingly recognized for their potential to catalyse transformative shifts in worldviews. Central to these transformations may be the integration of self-transcendent states. This mixed-methods study explored transformative psychedelic experiences, focussing on subsequent epistemic shifts. Ninety participants completed the Awe Experience Scale (AWE-S), and the...

Brain Dynamics of Classical Psychedelics Show Paradoxical Hierarchical Flattening With Increased Complexity

SSRN Electronic Journal 2026 Jakub Vohryzek, Elvira Garcia Guzman, Morten L. Kringelbach et al. 1 citation

Despite divergent behavioral and phenomenological profiles, both psychedelic states and reduced states of consciousness have been associated with a flattening of the brain's functional hierarchy. To address this apparent paradox, we developed a more specific definition of hierarchy based on the proximity of the brain to thermodynamic equilibrium and then applied it to investigate the changes to...

Ceremonial Psychedelic Experiences and Changes in Mental Health Outcomes in Those with Adverse Childhood Experiences

Psychedelic Medicine December 15, 2025 M. Mehmood, Rebecka Bremler, M. Spriggs et al.

Background:Adverse childhood experiences (ACEs) are known to contribute to mental health issues and interfere with response to mental health interventions. Psychedelics have been found to improve mental health outcomes; however, the exploration of the effects of psychedelics on mental health in those with higher ACEs remains limited. The present study aimed to examine mental health outcomes and...

Defining ‘psychedelic’

December 4, 2025 Avery Ostrand, Matthew M. Nour, Christopher Timmermann et al. 2 citations preprint

Humphry Osmond coined the term ‘psychedelic’ in 1956, conjoining ‘psyche’ for ‘soul’ and ‘delic’ from ‘dêlos’ for ‘to manifest’ or ‘illuminate.’ Soul-illumination is an adjective that describes a psychological state or process. However, Osmond’s intention was to use the adjective to name— not just a state— but a category of drug that can induce the subjective effect as its principal action;...

Micro-Messiahs: When Psychedelics and Politics Meet

December 2, 2025 Leor Roseman

The recent mainstreaming of psychedelics has distanced itself from the countercultural image of the past, yet the question of whether psychedelics are political remains pressing. What happens when psychedelics meet politics?On one hand lies the politics of the unitive mystical experience: harmony, beyond good & evil, beyond space & time, and with love to all. Studying ayahuasca groups of...

A Virtual Clinical Trial of Psychedelics to Treat Patients With Disorders of Consciousness

Advanced Science November 20, 2025 Paolo Cardone, Charlotte Martial, Yonatan Sanz Perl et al. 3 citations

Abstract Disorders of consciousness (DoC), including unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), have limited treatment options and are characterized by low complexity of brain activity. Recent research suggests that psychedelic drugs, which enhance the complexity of brain activity, could offer promising therapies. Here, individualized whole‐brain computational...

Dissociable effects of LSD and MDMA on striato-cortical connectivity in healthy subjects.

Neuropsychopharmacology October 31, 2025 Natalie Ertl, Imran Ashraf, Lisa Azizi et al. 1 citation

Lysergic acid diethylamide (LSD) and 3,4-Methylenedioxymethamphetamine (MDMA) are widely used psychoactive drugs and their potential use in psychiatric medicine is currently generating interest. The mechanism by which these drugs may assist recovery in various disorders such as addiction and post-traumatic stress disorder (PTSD) is still not well understood. Most investigations of the effects...

Improved mental health outcomes and normalised spontaneous EEG activity in veterans reporting a history of traumatic brain injuries following participation in a psilocybin retreat

Frontiers in Psychiatry August 6, 2025 Grace Blest‐hopley, Giuseppe Pasculli, Simon Ruffell et al. 3 citations

Introduction Psilocybin, a serotonergic psychedelic, has shown therapeutic potential in treating mental health disorders by, amongst the many effects, promoting neuroplasticity and reorganising functional connectivity across cortical and subcortical networks involved in emotion and cognition. Veterans with traumatic brain injuries (TBI) often experience chronic neurological and psychological...

97. NEURAL AND BEHAVIORAL EVIDENCE FROM REINFORCEMENT LEARNING CONVERGE IN SUPPORT OF RELAXED BELIEFS UNDER LSD

International Journal of Neuropsychopharmacology August 1, 2025 Jonathan W. Kanen, Andrea I. Luppi, Q. Luo et al.

Abstract Background The REBUS (RElaxed Beliefs Under pSychedelics) and the anarchic brain model of psychedelic drug action proposes that confidence in beliefs – and thus expectations (priors) – are relaxed under these drugs. The brain makes inferences to minimize surprise, or discrepant expectations and outcomes (prediction error [PE]), and better model the world. We recently showed that the...

Exploring the Therapeutic Effects of Psychedelics Administered to Military Veterans in Naturalistic Retreat Settings

Brain and Behavior July 1, 2025 Megan Calnan, Grace Blest‐hopley, Chris Busch et al. 4 citations

Abstract Background : Military veterans are at risk of various mental health conditions, with profound implications for post‐deployment quality of life. Current treatment options encounter high dropout rates and non‐responsiveness, and overlook the importance of community building in veterans’ holistic recovery. Preliminary research suggests psychedelics offer therapeutic benefits for...

Correction: Dissociable effects of psilocybin and escitalopram for depression on processing of musical surprises.

Mol Psychiatry July 1, 2025 Rebecca Harding, Neomi Singer, Matthew B. Wall et al. correction

The following part of the abstract had a minor error: ‘Following PT, there was greater activation in the ventromedial prefrontal cortex and sensory regions, and reduced activation in the angular gyrus.’ This is now corrected to ‘Following PT, there was decreased activation in the ventromedial prefrontal cortex and angular gyrus, and greater activation in sensory regions.’ The original article...

Reframing psychedelic regulation: Tools, not treatments

Drug Science Policy and Law June 16, 2025 Max Wolff, Natalie Gukasyan, Leor Roseman et al. 5 citations

Current regulation frameworks for medicines struggle to address the combination of pharmacological and psychotherapeutic elements in psychedelic therapy. We propose a more appropriate and advantageous approach may be to regulate psychedelic drugs as therapeutic tools or adjuncts to psychotherapy, rather than as treatments for specific mental disorders. Drawing parallels with anesthetics, which...

Enhanced meaning in life following psychedelic use: converging evidence from controlled and naturalistic studies

Frontiers in Psychology June 6, 2025 William Roseby, Hannes Kettner, Leor Roseman et al. 6 citations

Introduction Psychedelics, such as psilocybin, are increasingly recognized for their propensity to elicit powerful subjective experiences that carry personal meaning. While research has demonstrated the capacity for these compounds to promote psychological wellbeing, it has yet to be shown to what extent they modulate "meaning in life", a specific contributor to mental and physical health....

An international Delphi consensus for reporting of setting in psychedelic clinical trials.

Nature Medicine June 3, 2025 Chloé Pronovost-Morgan, Kyle T. Greenway, Leor Roseman et al. 26 citations

Psychedelic substances exhibit complex interactions with the 'set and setting' of use, that is, the mental state of the user and the environment in which a psychedelic experience takes place. Despite these contextual variables' known importance, psychedelic research has lacked methodological rigor in reporting extra-pharmacological factors. This study aimed to generate consensus-based...

Reduced Brain Responsiveness to Emotional Stimuli With Escitalopram But Not Psilocybin Therapy for Depression

American Journal of Psychiatry May 7, 2025 Matthew B. Wall, Lysia Demetriou, Bruna Giribaldi et al. 16 citations

Despite large improvements in depressive symptoms in the psilocybin group, psilocybin therapy had only a minor effect on brain responsiveness to emotional stimuli. These results are consistent with prior findings that the antidepressant action of SSRIs is often accompanied by a reduction in emotional responsiveness, but this effect may not occur in psychedelic therapy.

Dissociable effects of psilocybin and escitalopram for depression on processing of musical surprises

Molecular Psychiatry April 26, 2025 Rebecca Harding, Neomi Singer, Talma Hendler et al. 4 citations

Abstract Psilocybin therapy (PT) is emerging as an effective intervention for Major Depressive Disorder (MDD), offering comparable efficacy to conventional treatments like selective serotonin reuptake inhibitors (SSRIs). Music, an emotionally evocative stimulus, provides a valuable tool to explore changes in hedonic and predictive processing mechanisms via expectancy violations, or ‘surprises’....

Network control energy reductions under DMT relate to serotonin receptors, signal diversity, and subjective experience.

Communications Biology April 18, 2025 S Parker Singleton, Christopher Timmermann, Andrea I. Luppi et al. 17 citations

Psychedelics offer a profound window into the human brain through their robust effects on perception, subjective experience, and brain activity patterns. The serotonergic psychedelic N,N-dimethyltryptamine (DMT) induces a profoundly immersive altered state of consciousness lasting under 20 min, allowing the entire experience to be captured during a single functional magnetic resonance imaging...