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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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Self-Medication for Chronic Pain Using Classic Psychedelics: A Qualitative Investigation to Inform Future Research

Frontiers in Psychiatry November 12, 2021 Julia Bornemann, James B. Close, Meg J. Spriggs et al. 43 citations

Background: Chronic Pain is among the leading causes of disability worldwide with up to 60% of patients suffering from comorbid depression. Psychedelic-assisted therapy has recently been found effective in treating a host of mental health issues including depression and has historically been found to be useful in treating pain. Reports of self-medication for chronic pain using psychedelic drugs...

On Revelations and Revolutions: Drinking Ayahuasca Among Palestinians Under Israeli Occupation

Frontiers in Psychology August 27, 2021 Leor Roseman, Nadeem Karkabi 11 citations

The ritualistic use of ayahuasca can induce a feeling of unity and harmony among group members. However, such depoliticized feelings can come in the service of a destructive political status quo in which Palestinians are marginalized. Through 31 in-depth interviews of Israelis and Palestinians who drink ayahuasca together, and through participatory observations, such rituals were examined. In...

Decreased brain modularity after psilocybin therapy for depression.

Research Square May 20, 2021 Richard E. Daws, Christopher Timmerman, Bruna Giribaldi et al. 11 citations

Abstract Importance Psilocybin therapy shows antidepressant potential; our data link its antidepressant effects to decreased brain network modularity post-treatment. Objective To assess the sub-acute impact of psilocybin on brain activity in patients with depression. Design Pre vs post-treatment resting-state functional MRI (fMRI) was recorded in two trials: 1) Open-label treatment-resistant...

Psychedelic Communitas: Intersubjective Experience During Psychedelic Group Sessions Predicts Enduring Changes in Psychological Wellbeing and Social Connectedness.

Front Pharmacol March 25, 2021 Hannes Kettner, Fernando E. Rosas, C. Timmermann et al. 205 citations

Psychedelic Communitas: Intersubjective Experience During Psychedelic Group Sessions Predicts Enduring Changes in Psychological Wellbeing and Social Connectedness.

LSD alters dynamic integration and segregation in the human brain.

Neuroimage February 15, 2021 Andrea I. Luppi, Robin Carhart-Harris, Leor Roseman et al. 186 citations

Investigating changes in brain function induced by mind-altering substances such as LSD is a powerful method for interrogating and understanding how mind interfaces with brain, by connecting novel psychological phenomena with their neurobiological correlates. LSD is known to increase measures of brain complexity, potentially reflecting a neurobiological correlate of the especially rich...

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

Neuroimage January 29, 2021 Beatrice M. Jobst, Selen Atasoy, Adrián Ponce-Alvarez et al. 37 citations

Lysergic acid diethylamide (LSD) is a potent psychedelic drug, which has seen a revival in clinical and pharmacological research within recent years. Human neuroimaging studies have shown fundamental changes in brain-wide functional connectivity and an expansion of dynamical brain states, thus raising the question about a mechanistic explanation of the dynamics underlying these alterations....

Positive expectations predict improved mental-health outcomes linked to psychedelic microdosing

Scientific Reports January 21, 2021 Laura Kaertner, Michael B. Steinborn, Hannes Kettner et al. 152 citations

Abstract Psychedelic microdosing describes the ingestion of near-threshold perceptible doses of classic psychedelic substances. Anecdotal reports and observational studies suggest that microdosing may promote positive mood and well-being, but recent placebo-controlled studies failed to find compelling evidence for this. The present study collected web-based mental health and related data using...

Relational Processes in Ayahuasca Groups of Palestinians and Israelis.

Frontiers in Pharmacology 2021 Leor Roseman, Yiftach Ron, Antwan Saca et al. 39 citations

Psychedelics are used in many group contexts. However, most phenomenological research on psychedelics is focused on personal experiences. This paper presents a phenomenological investigation centered on intersubjective and intercultural relational processes, exploring how an intercultural context affects both the group and individual process. Through 31 in-depth interviews, ceremonies in which...

Serotonergic psychedelics LSD & psilocybin increase the fractal dimension of cortical brain activity in spatial and temporal domains

Neuroimage June 30, 2020 Thomas F. Varley, Robin Carhart-Harris, Leor Roseman et al. 91 citations

Psychedelic drugs, such as psilocybin and LSD, represent unique tools for researchers investigating the neural origins of consciousness. Currently, the most compelling theories of how psychedelics exert their effects is by increasing the complexity of brain activity and moving the system towards a critical point between order and disorder, creating more dynamic and complex patterns of neural...

Neural correlates of the LSD experience revealed by multimodal neuroimaging

UNC Libraries April 22, 2020 Peter J. Hellyer, Luke T. J. Williams, Ben Sessa et al. 1 citation

Lysergic acid diethylamide (LSD), the prototypical “psychedelic,” may be unique among psychoactive substances. In the decades that followed its discovery, the magnitude of its effect on science, the arts, and society was unprecedented. LSD produces profound, sometimes life-changing experiences in microgram doses, making it a particularly powerful scientific tool. Here we sought to examine its...

Updating the dynamic framework of thought: Creativity and psychedelics.

Neuroimage March 8, 2020 Manesh Girn, Caitlin Mills, Leor Roseman et al. 139 citations

Contemporary investigations regard creativity as a dynamic form of cognition that involves movement between the dissociable stages of creative generation and creative evaluation. Our recently proposed Dynamic Framework of Thought (Christoff et al., 2016) offered a conceptualization of these stages in terms of an interplay between sources of constraint and variability on thought. This initial...

Therapeutic mechanisms of psilocybin: Changes in amygdala and prefrontal functional connectivity during emotional processing after psilocybin for treatment-resistant depression

Journal of Psychopharmacology January 16, 2020 Lea J. Mertens, Matthew B. Wall, Leor Roseman et al. 211 citations

Background: Psilocybin has shown promise as a treatment for depression but its therapeutic mechanisms are not properly understood. In contrast to the presumed actions of antidepressants, we recently found increased amygdala responsiveness to fearful faces one day after open-label treatment with psilocybin (25 mg) in 19 patients with treatment-resistant depression, which correlated with...

Neural correlates of the DMT experience assessed with multivariate EEG.

Sci Rep November 19, 2019 Christopher Timmermann, Leor Roseman, Michael Schartner et al. 325 citations

Studying transitions in and out of the altered state of consciousness caused by intravenous (IV) N,N-Dimethyltryptamine (DMT - a fast-acting tryptamine psychedelic) offers a safe and powerful means of advancing knowledge on the neurobiology of conscious states. Here we sought to investigate the effects of IV DMT on the power spectrum and signal diversity of human brain activity (6 female, 7...

Functional imaging investigation of psychedelic visual imagery

Spiral (Imperial College London) October 1, 2019 Leor Roseman 4 citations

Psychedelics can induce eyes-closed imagery in which various visions can be experienced. These visions vary from simple geometrical patterns, to more complex imagery, to full immersion within “other realms”. Past studies suggest that the visual cortex is involved in processing these visions, yet these studies were limited into investigation of activity. In this thesis, the aim was to expand on...

Emotional breakthrough and psychedelics: Validation of the Emotional Breakthrough Inventory.

J Psychopharmacol July 11, 2019 Leor Roseman, Eline Haijen, Kelvin Idialu-Ikato et al. 415 citations

Background: Psychedelic therapy is gaining recognition and the nature of the psychedelic experience itself has been found to mediate subsequent long-term psychological changes. Much emphasis has been placed on the occurrence of mystical-type experiences in determining long-term responses to psychedelics yet here we demonstrate the importance of another component, namely: emotional breakthrough....

Dynamical exploration of the repertoire of brain networks at rest is modulated by psilocybin.

Neuroimage May 25, 2019 Louis-David Lord, Paul Expert, Selen Atasoy et al. 249 citations

Growing evidence from the dynamical analysis of functional neuroimaging data suggests that brain function can be understood as the exploration of a repertoire of metastable connectivity patterns ('functional brain networks'), which potentially underlie different mental processes. The present study characterizes how the brain's dynamical exploration of resting-state networks is rapidly modulated...

Serotonergic Psychedelics LSD & Psilocybin Increase the Fractal Dimension of Cortical Brain Activity in Spatial and Temporal Domains

bioRxiv (Cold Spring Harbor Laboratory) January 11, 2019 Tf. Varley, Robin Carhart-Harris, Leor Roseman et al. 8 citations preprint

Abstract Psychedelic drugs, such as psilocybin and LSD, represent unique tools for researchers in-vestigating the neural origins of consciousness. Currently, the most compelling theories of how psychedelics exert their effects is by increasing the complexity of brain activity and moving the system towards a critical point between order and disorder, creating more dynamic and complex patterns of...

Predicting Responses to Psychedelics: A Prospective Study

Frontiers in Pharmacology November 2, 2018 Adam Hampshire, Christopher Timmermann, Christopher Timmermann et al. 422 citations

Responses to psychedelics are notoriously difficult to predict, yet significant work is currently underway to assess their therapeutic potential and the level of interest in psychedelics among the general public appears to be increasing. We aimed to collect prospective data in order to improve our ability to predict acute- and longer-term responses to psychedelics. Individuals who planned to...

Predicting Responses to Psychedelics: A Prospective Study

Frontiers in Pharmacology November 2, 2018 Adam Hampshire, Christopher Timmermann, Christopher Timmermann et al. 422 citations

Responses to psychedelics are notoriously difficult to predict, yet significant work is currently underway to assess their therapeutic potential and the level of interest in psychedelics among the general public appears to be increasing. We aimed to collect prospective data in order to improve our ability to predict acute- and longer-term responses to psychedelics. Individuals who planned to...

Psychedelics, Meditation, and Self-Consciousness

Frontiers in Psychology September 4, 2018 Raphaël Millière, Robin Carhart-Harris, Leor Roseman et al. 402 citations

In recent years, the scientific study of meditation and psychedelic drugs has seen remarkable developments. The increased focus on meditation in cognitive neuroscience has led to a cross-cultural classification of standard meditation styles validated by functional and structural neuroanatomical data. Meanwhile, the renaissance of psychedelic research has shed light on the neurophysiology of...

DMT Models the Near-Death Experience

Frontiers in Psychology August 15, 2018 Christopher Timmermann, Leor Roseman, L. Williams et al. 228 citations

Near-death experiences (NDEs) are complex subjective experiences, which have been previously associated with the psychedelic experience and more specifically with the experience induced by the potent serotonergic, N,N-Dimethyltryptamine (DMT). Potential similarities between both subjective states have been noted previously, including the subjective feeling of transcending one's body and...

Altered trajectories in the dynamical repertoire of functional network states under psilocybin

bioRxiv (Cold Spring Harbor Laboratory) July 25, 2018 Louis-David Lord, Paul Expert, Selen Atasoy et al. 10 citations preprint

Abstract Brain activity can be understood as the exploration of a dynamical landscape of activity configurations over both space and time. This dynamical landscape may be defined in terms of spontaneous transitions within a repertoire of discrete metastable states of functional connectivity (FC), which underlie different mental processes. However, it remains unclear how the brain’s dynamical...

Effects of psilocybin therapy on personality structure

Acta Psychiatrica Scandinavica June 19, 2018 David Erritzøe, Leor Roseman, Matthew M. Nour et al. 268 citations

Objective To explore whether psilocybin with psychological support modulates personality parameters in patients suffering from treatment‐resistant depression (TRD). Method Twenty patients with moderate or severe, unipolar, TRD received oral psilocybin (10 and 25 mg, one week apart) in a supportive setting. Personality was assessed at baseline and at 3‐month follow‐up using the Revised NEO...

Correction to: The hidden therapist: evidence for a central role of music in psychedelic therapy.

Psychopharmacology May 1, 2018 Mendel Kaelen, Bruna Giribaldi, Jordan Raine et al. 9 citations correction

The article The hidden therapist: evidence for a central role of music in psychedelic therapy, written by Mendel Kaelen, Bruna Giribaldi, Jordan Raine, Lisa Evans, Christopher Timmerman, Natalie Rodriguez, Leor Roseman, Amanda Feilding, David Nutt, Robin Carhart-Harris, was originally published electronically on the publisher's internet portal.

Psychedelics and the essential importance of context.

J Psychopharmacol February 15, 2018 Robin Carhart-Harris, Leor Roseman, Eline Haijen et al. 646 citations

Psychedelic drugs are making waves as modern trials support their therapeutic potential and various media continue to pique public interest. In this opinion piece, we draw attention to a long-recognised component of the psychedelic treatment model, namely ‘set’ and ‘setting’ – subsumed here under the umbrella term ‘context’. We highlight: (a) the pharmacological mechanisms of classic...