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Leor Roseman

Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, UK. l.roseman@exeter.ac.uk.

90 papers in the library · 6,130 citations · publishing 2014-2026

Papers

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. 2 citations

Simulated administration of LSD and psilocybin in computational models of patients with disorders of consciousness (DoC), including unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), shifted brain activity closer to criticality—the phase transition between order and chaos. The effect was greater in MCS patients. In UWS patients, the treatment response correlated with structural connectivity, while in MCS patients it aligned with baseline functional connectivity. These results provide a computational foundation for using psychedelics in DoC treatment and highlight the potential role of computational modeling in drug discovery and personalized medicine.

Dynamic medial parietal and hippocampal deactivations under DMT relate to sympathetic output and altered sense of time, space, and the self

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.

Brain dynamics of classical psychedelics show paradoxical hierarchical flattening with increased complexity

bioRxiv (Cold Spring Harbor Laboratory) December 22, 2024 Jakub Vohryzek, Morten L. Kringelbach, Edmundo Lopez-Sola et al. 1 citation preprint

Both psychedelic states and reduced states of consciousness flatten the brain's functional hierarchy, yet their behavioral and phenomenological profiles differ. To resolve this paradox, researchers defined hierarchy by the brain's proximity to thermodynamic equilibrium and examined changes induced by three serotonergic psychedelics: psilocybin, LSD, and DMT. All three consistently reduced the functional hierarchy globally. Unlike loss of consciousness, psychedelics moved the brain toward equilibrium while increasing neural activity complexity, indicating a distinct mechanism involving altered configuration and differentiation of resting-state networks. This work demonstrates how statistical mechanics metrics can characterize different global brain states, advancing understanding of consciousness as an emergent collective process.

The Role of the Dorsolateral Prefrontal Cortex in Ego Dissolution and Emotional Arousal During the Psychedelic State

bioRxiv Preprint Server December 9, 2024 Clayton R. Coleman, Kenneth Shinozuka, Robert Tromm et al. 1 citation preprint

Lysergic acid diethylamide (LSD) alters consciousness by affecting brain connectivity, particularly in the dorsolateral prefrontal cortex (DLPFC). Using fMRI and MEG data from healthy participants, the study found that ego dissolution—a hallmark of the psychedelic experience—was positively correlated with increased functional connectivity between the left and right DLPFC, thalamus, and fusiform face area. Emotional arousal was linked to stronger connectivity between the right DLPFC, intraparietal sulcus, and salience network. A confirmatory analysis supported these findings. MEG data showed that LSD increased directed information flow from the thalamus to the DLPFC in the theta band, suggesting disrupted thalamic gating contributes to ego dissolution. These results indicate a key role for the DLPFC in LSD-induced states of consciousness.

Increased sensitivity to strong perturbations in a whole-brain model of LSD

bioRxiv Preprint Server January 5, 2021 Beatrice M. Jobst, Selen Atasoy, Adrián Ponce-Alvarez et al. 1 citation preprint

LSD alters brain dynamics by shifting the brain's global working point further from a stable equilibrium, as shown by consistently higher Perturbational Integration Latency Index (PILI) values after intake. Using a whole-brain computational model perturbed in silico, the largest differences were found in the limbic, visual, and default mode networks. Greater variability of PILI values across brain regions under LSD indicates higher response diversity to external perturbations. These findings provide insights into the brain-wide dynamical changes underlying the psychedelic state and suggest possible clinical applications for psychiatric disorders.

Accurate and Interpretable Prediction of Antidepressant Treatment Response from Receptor-informed Neuroimaging

bioRxiv (Cold Spring Harbor Laboratory) Hanna M. Tolle, Andrea I Luppi, Timothy Lawn et al. 1 citation preprint

A geometric deep learning model called graphTRIP predicts post-treatment depression severity from pretreatment clinical and brain imaging data. Trained on a clinical trial comparing psilocybin and escitalopram, it achieves strong predictive accuracy (r = 0.75) and generalizes to an independent dataset. The model links better outcomes to reduced functional coupling within serotonin systems and broader serotonergic integration with sensory-motor networks. Causal analysis shows a group-level advantage of psilocybin over escitalopram but identifies individuals with specific stress-related neuromodulatory profiles who may benefit more from escitalopram, advancing precision medicine and biomarker discovery in depression.

Micro-Messiahs and the Revolutionary Dynamics of Psychedelic Diffusion

Religions June 24, 2026 Leor Roseman

Prophetic or messianic states of consciousness can be charged with moral urgency and become active, historical, and political. The paper examines psychedelic micro-messianic phenomenology and revolutionary dynamics through three historical figures: Allen Ginsberg (LSD), Master Irineu (Daime/ayahuasca), and John Wilson/Moonhead (peyote). In moments of tension and uncertainty, psychedelics can catalyze micro-messianic movements that diffuse these substances into new situations. A revelatory event motivates the subject to spread the substance and practice, creating a movement that eventually becomes routinized or inverted, then stabilizes into a new status quo from which another revelatory event may arise. The analysis draws on Weber, Wallace, Kuhn, Taves, Whitehouse, Rogers, Badiou, and others to show how psychedelic insights and actions intertwine, with revelations seeking to ripple outward into movements.

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

June 21, 2026 Jonathan David, Aviva Berkovich‐ohana, Yair Dor‐ziderman et al. preprint

Ayahuasca use among ultra-Orthodox (Haredi) Jews is adapted to Jewish contexts, with ceremonies modified to fit religious norms. Motivations for use are primarily therapeutic. Acute experiences include Jewish and Jewish mystical visionary content. Longer-term effects include strengthened belief, connection to Judaism, and changes in religious practice. Religious tensions arise from ayahuasca's perceived foreignness, concerns about idolatry, mixed-gender participation, and competing authority structures. Strategies to address these tensions include medicalization, making the set, setting, and experience religiously permissible ("koshering"), and framing ceremonies as liminal spaces. The findings highlight psychedelics' contextual flexibility and diffusion into understudied populations.

Effects of psychedelic use on authoritarian attitudes revisited.

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.

Towards social curative psychedelic treatment

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

Psychedelic-assisted therapies are effective for mental health conditions but are usually delivered individually, missing opportunities to build shared social identity among participants. Group-based interventions foster empathy, connectedness, and social functioning. Integrating 'social cure' principles from social identity theory could enhance therapeutic efficacy by promoting interconnectedness in supportive group settings. This article argues for combining these approaches, which have developed separately, to provide a theoretical foundation for group-based therapies and guide responsible implementation of socially informed psychedelic treatments, leading to a more comprehensive and socially embedded mental health care model.

Micro-Messiahs: When Psychedelics and Politics Meet

December 2, 2025 Leor Roseman

Psychedelics can catalyze micro-messianic events: bursts that disrupt the status quo and fuel collective movements animated by hope, mission, and meaning. Studying ayahuasca groups of Palestinians and Israelis, the author observed that a unitive mystical ethos can bypass political tensions, yet revelatory-revolutionary events with liberatory aspirations also occur. These prophetic, morally urgent states of consciousness are active and political. Through a literature review focused on Allen Ginsberg, Master Irineu, and John Wilson (Moonhead)—figures associated with LSD, Daime, and peyote—the paper proposes that in moments of political anxiety, psychedelics can inspire redemptive actions and drive the diffusion of psychedelic practices across social, cultural, and political boundaries.

Revealing Changes in Linear and Nonlinear Functional Connectivity After Psilocybin and Escitalopram Treatment in Patients with Depression

bioRxiv (Cold Spring Harbor Laboratory) March 10, 2025 Shaun K.l. Quah, Cameron Glick, Leor Roseman et al. preprint

People with major depression who responded to either psilocybin or escitalopram showed distinct changes in brain network connectivity compared to non-responders. Responders had increased linear connectivity within the ventral attention network and greater nonlinear connectivity within the default mode and ventral attention networks. Psilocybin responders showed enhanced coordination between higher-order networks, while escitalopram responders showed reduced connectivity within networks linked to self-referential thought and salience processing. These patterns suggest the two antidepressants work through different mechanisms, with nonlinear connectivity analyses revealing effects not captured by traditional linear measures.

Human brain changes after first psilocybin 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.

Observational cohort study of a group-based VR program to improve mental health and wellbeing in people with life-threatening illnesses

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.

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

arXiv Preprint Archive March 28, 2025 Marcus J. Glennon, Catherine I. V. Bird, Prateek Yadav et al.

Setting up a psychedelic study is a long and complex process that presents unique challenges not yet standardized. This review brings together major UK research teams to formalize these considerations, identify ongoing debates, and provide a practical guide for researchers and policymakers. It addresses challenges to existing assumptions about psychiatric prescribing, the placebo effect, and definitions of selfhood. The paper can be read end-to-end or used as a manual with sections for specific needs.