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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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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. 4 citations

Abstract N,N-Dimethyltryptamine (DMT) is a serotonergic psychedelic, known to rapidly induce short-lasting alterations in conscious experience, characterized by a profound and immersive sense of physical transcendence alongside rich and vivid auditory distortions and visual imagery. Multimodal neuroimaging data paired with dynamic analysis techniques offer a valuable approach for identifying...

A reflection on paradigmatic tensions within the FDA advisory committee for MDMA-assisted therapy.

Journal of psychopharmacology (Oxford, England) April 1, 2025 Leor Roseman 12 citations

The recent rejection of 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy by the U.S. Food and Drug Administration (FDA) is a dramatic moment in the re-emergence of psychedelic research. In this perspective, I argue that it represents a case study for paradigmatic tensions within psychopharmacology. The regulatory system is still influenced by a paradigm that sees the therapeutic...

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

Human Brain Mapping April 1, 2025 Clayton R. Coleman, Kenneth Shinozuka, Robert Tromm et al. 4 citations

Lysergic acid diethylamide (LSD) is a classic serotonergic psychedelic that induces a profoundly altered conscious state. In conjunction with psychological support, it is currently being explored as a treatment for generalized anxiety disorder and depression. The dorsolateral prefrontal cortex (DLPFC) is a brain region that is known to be involved in mood regulation and disorders; hypofunction...

Learning from Boundlessness: Psychedelic induced awe and epistemic shifts towards a holistic worldview

Research Square March 31, 2025 Eirini K. Argyri, Flora Fraser, Stefan Schilling et al.

Abstract Psychedelic substances are increasingly recognized for their potential to catalyse transformative shifts in worldviews. Central to these transformations are states of awe, a self-transcendent, epistemic emotion. This mixed-methods study explored how awe during psychedelic trips relates to lasting changes in boundaries between self and world, and epistemic shifts that follow...

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

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

Setting up a psychedelic study can be a long, arduous, and kafkaesque process. This rapidly-developing field poses several unique challenges for researchers, necessitating a range of considerations that have not yet been standardised. Many of the complexities inherent to psychedelic research also challenge existing assumptions around, for example, approaches to psychiatric prescribing, the...

LSD reconfigures the frequency-specific network landscape of the human brain

bioRxiv March 24, 2025 Kenneth Shinozuka, Mattia Rosso, Clayton R. Coleman et al. 3 citations preprint

Abstract Lysergic acid diethylamide (LSD) and other psychedelic substances profoundly alter human consciousness. While several studies have demonstrated changes in brain function and connectivity associated with psychedelics, we still have a limited understanding of how LSD reshapes brain networks operating across different frequency bands. In this study, we applied the recently developed...

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 C. Glick, Leor Roseman et al. preprint

Abstract Major Depressive Disorder (MDD) is typically characterized by altered linear functional connectivity (FC) across large-scale brain networks. Yet, it is unclear whether similar alterations are observed when nonlinear FC is examined. This study investigated how antidepressant treatment (i.e., psilocybin and escitalopram) modulates both linear FC and nonlinear FC in individuals with MDD....

LSD flattens the hierarchy of directed information flow in fast whole-brain dynamics.

Imaging Neurosci (Camb) January 3, 2025 Kenneth Shinozuka, Prejaas K.b. Tewarie, Andrea I. Luppi et al. 9 citations

Psychedelics are serotonergic drugs that profoundly alter consciousness, yet their neural mechanisms are not fully understood. A popular theory, RElaxed Beliefs Under pSychedelics (REBUS), posits that psychedelics flatten the hierarchy of information flow in the brain. Here, we investigate hierarchy based on the imbalance between sending and receiving brain signals, as determined by directed...

Diminished functional gradient of the precuneus during altered states of consciousness

bioRxiv December 17, 2024 Dian Lyu, Ram Adapa, Robin Carhart-Harris et al. preprint

Abstract The relationship between the default mode network (DMN) and task-positive networks, such as the frontoparietal control network (FPCN), is a prominent feature of functional connectivity (FC) in the human brain. This relationship is primarily anticorrelated at rest in healthy brains and is disrupted in altered states of consciousness. Although the DMN and FPCN seem to perform distinct...

Healing through the Body: The Potential Role of Daoist Meditation in Psychedelic Therapy

PsyArXiv December 4, 2024 Kenneth Shinozuka, Ben Cox, Leor Roseman 1 citation preprint

Psychedelics are hallucinogenic drugs that have the potential to treat depression, post-traumatic stress disorder, and other psychiatric conditions. The dominant paradigm in contemporary psychedelic-assisted therapy is non-directive; that is, participants undergo the psychedelic treatment with minimal external guidance from therapists. However, the clinical outcomes of psychedelic therapy could...

The Reporting of Setting in Psychedelic Clinical Trials (ReSPCT) Guidelines: An international Delphi consensus study

Research Square November 18, 2024 Chloé Pronovost-Morgan, Kyle T. Greenway, Leor Roseman 2 citations

Abstract Background Psychedelic substances exhibit complex interactions with the ‘set and setting’ of use, i.e., the internal state of the user and the external environment in which a psychedelic experience takes place. Despite the known importance of these contextual variables, psychedelic research has suffered from methodological weaknesses in reporting extra-pharmacological factors and from...

Long-term effects of psilocybin on dynamic and effectivity connectivity of fronto-striatal-thalamic circuits

bioRxiv (Cold Spring Harbor Laboratory) November 7, 2024 Lorenzo Pasquini, Jakub Vohryzek, Anira Escrichs et al. 4 citations preprint

Abstract Psilocybin has been shown to induce fast and sustained improvements in mental well-being across various populations, yet its long-term mechanisms of action are not fully understood. Initial evidence suggests that longitudinal functional and structural brain changes implicate fronto-striatal-thalamic (FST) circuitry, a broad system involved in goal-directed behavior and motivational...

Co-administration of midazolam and psilocybin: differential effects on subjective quality versus memory of the psychedelic experience.

Translational Psychiatry September 12, 2024 Christopher R. Nicholas, Matthew I Banks, Richard C Lennertz et al. 10 citations

Aspects of the acute experience induced by the serotonergic psychedelic psilocybin predict symptomatic relief in multiple psychiatric disorders and improved well-being in healthy participants, but whether these therapeutic effects are immediate or are based on memories of the experience is unclear. To examine this, we co-administered psilocybin (25 mg) with the amnestic benzodiazepine midazolam...

Interrupting the Psychedelic Experience Through Contextual Manipulation to Study Experience Efficacy.

JAMA Netw Open July 1, 2024 Leor Roseman, David Erritzøe, David Nutt et al. 12 citations

This quality improvement study investigates the association of interruptions during psychedelic therapy with ratings of intensity of experience.

Effects of Psychedelics in Older Adults: A Prospective Cohort Study.

Am J Geriatr Psychiatry May 19, 2024 Hannes Kettner, Leor Roseman, Adam Gazzaley et al. 18 citations

OBJECTIVE: Affective symptoms such as anxiety, low mood, and loneliness are prevalent and highly debilitating symptoms among older adults (OA). Serotonergic psychedelics are currently investigated as novel interventions for affective disorders, yet little is known regarding their effects in OA. We investigated the mental health effects and psychological mechanisms of guided psychedelic group...

The intimacy of psychedelics, language, and consciousness.

May 2, 2024 Jeremy I Skipper, George Fejer, Matthieu Koroma et al. preprint

This interview explores the intimate relationship between language and consciousness, drawing insights from aphasia phenomenology, psychedelic experiences, and neuroscientific theories. Jeremy I. Skipper, a cognitive neuroscientist, argues that language is not merely a tool for reporting conscious experiences but plays a generative role in shaping and sustaining consciousness itself. He...

The flattening of spacetime hierarchy of the N,N-dimethyltryptamine brain state is characterized by harmonic decomposition of spacetime (HADES) framework.

National Science Review May 1, 2024 Jakub Vohryzek, Joana Cabral, Christopher Timmermann et al. 13 citations

The human brain is a complex system, whose activity exhibits flexible and continuous reorganization across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over time with their changes in various brain states...

Improvements in well-being following naturalistic psychedelic use and underlying mechanisms of change in older adults: A prospective cohort study.

Research Square March 8, 2024 Hannes Kettner, Leor Roseman, Adam Gazzaley et al. 5 citations

Affective symptoms such as anxiety, low mood, and loneliness are prevalent and highly debilitating symptoms among older adults (OA). Serotonergic psychedelics are novel experimental interventions for affective disorders, yet little is known regarding their effects in OA. Using a prospective cohort design, we identified 62 OA (age ≥ 60 years) and 62 matched younger adults (YA) who completed...

Unique Psychological Mechanisms Underlying Psilocybin Therapy Versus Escitalopram Treatment in the Treatment of Major Depressive Disorder

International Journal of Mental Health and Addiction March 7, 2024 Brandon Weiss, Leor Roseman, Bruna Giribaldi et al. 26 citations

Abstract The mechanisms by which Psilocybin Therapy (PT) improves depression remain an important object of study, with scientists actively exploring acute psychological experiences and neurobiological processes as candidates. In a phase 2, double-blind, randomized, active comparator controlled trial involving patients with moderate-to-severe major depressive disorder, we investigated whether...

Effects of External Stimulation on Psychedelic State Neurodynamics.

ACS Chemical Neuroscience February 7, 2024 Pedro A. M. Mediano, Fernando E. Rosas, Christopher Timmermann et al. 60 citations

Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes, such as personality changes. These findings are particularly intriguing, given that a decrease of brain entropy is a robust indicator of loss of consciousness (e.g., from wakefulness to...

Psychedelics and sexual functioning: a mixed-methods study

Scientific Reports February 7, 2024 Tommaso Barba, Hannes Kettner, Caterina Radu et al. 24 citations

Abstract Do psychedelics affect sexual functioning postacutely? Anecdotal and qualitative evidence suggests they do, but this has never been formally tested. While sexual functioning and satisfaction are generally regarded as an important aspect of human wellbeing, sexual dysfunction is a common symptom of mental health disorders. It is also a common side effect of selective serotonin reuptake...

Brain dynamics predictive of response to psilocybin for treatment-resistant depression.

Brain Communications 2024 Jakub Vohryzek, Joana Cabral, Louis-David Lord et al. 33 citations

Psilocybin therapy for depression has started to show promise, yet the underlying causal mechanisms are not currently known. Here, we leveraged the differential outcome in responders and non-responders to psilocybin (10 and 25 mg, 7 days apart) therapy for depression-to gain new insights into regions and networks implicated in the restoration of healthy brain dynamics. We used large-scale brain...

A role for the serotonin 2A receptor in the expansion and functioning of human transmodal cortex.

Brain 2024 Andrea I. Luppi, Manesh Girn, Fernando E. Rosas et al. 25 citations

Integrating independent but converging lines of research on brain function and neurodevelopment across scales, this article proposes that serotonin 2A receptor (5-HT2AR) signalling is an evolutionary and developmental driver and potent modulator of the macroscale functional organization of the human cerebral cortex. A wealth of evidence indicates that the anatomical and functional organization...

LSD-induced changes in the functional connectivity of distinct thalamic nuclei.

Neuroimage December 1, 2023 Stefano Delli Pizzi, Piero Chiacchiaretta, Carlo Sestieri et al. 27 citations

The role of the thalamus in mediating the effects of lysergic acid diethylamide (LSD) was recently proposed in a model of communication and corroborated by imaging studies. However, a detailed analysis of LSD effects on nuclei-resolved thalamocortical connectivity is still missing. Here, in a group of healthy volunteers, we evaluated whether LSD intake alters the thalamocortical coupling in a...