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Frederick S. Barrett

Johns Hopkins University, Johns Hopkins Medicine

65 papers in the library · 7,663 citations · publishing 2015-2026

Papers

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Pilot study comparing the effects of high dose THC to high dose psilocybin and placebo in the set and setting of a classic psychedelic therapy session

Psychopharmacology August 27, 2026 Frederick S. Barrett, David Wolinsky, Zach Daily et al.

RATIONALE: Delta-9-tetrahydrocannabinol (Δ9-THC) has been reported to evoke psychedelic-like experiences at high doses in some individuals. However, the doses of Δ9-THC that occasion such effects and the phenomenology of these experiences are poorly understood. OBJECTIVES: This brief report presents preliminary findings from a pilot human laboratory study that directly compared the acute...

Integrating the Mystical Experience Questionnaire Into a Broader Psychometric Framework: English Validation of the Psychedelic Experience Scale and Comparison of Psilocybin and LSD Sessions Across Two Controlled Settings.

International Journal of Methods in Psychiatric Research June 1, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

For English, the validated part of Psychedelic Experience Scale (PES48) is a four-factor structure called the Mystical Experience Questionnaire (MEQ30). The other validated part of the PES48 consists of four more factors: two more mystical factors (paradoxicality and connectedness, which together with the MEQ30 form the MEQ40), and two more non-mystical factors (visual experience and...

Psilocybin-induced neurocardiogenic syncope: a case report.

Psychopharmacology May 28, 2026 Mazen A Atiq, Eli Weisman, Rodrigo B Guerra et al.

Psilocybin is among the serotonergic psychedelics closest to potential FDA approval, with growing evidence of therapeutic benefit across psychiatric conditions. As clinical trials expand, systematic characterization of adverse events (AEs) remains essential. While transient hypertensive responses are well documented, hypotensive events such as neurocardiogenic syncope (NCS) are rarely reported....

1080 Psilocybin Elicits Non-Linear Night to Night Changes in Sleep Spectral Power

SLEEPJ May 1, 2026 Matthew J. Reid, E. Weisman, Luis Luna Martinez et al.

Despite evidence of an acute effect of psilocybin on sleep physiology, its enduring effects beyond the period of acute administration and active metabolism remain unexplored. Within a clinical trial of psilocybin-assisted therapy for alcohol use disorder comorbid with major depressive disorder, we monitored sleep for ten continuous nights (3 pre-dose | 7 post-dose) in participants (N=22)...

Integrating the Mystical Experience Questionnaire Into a Broader Psychometric Framework: English Validation of the Psychedelic Experience Scale and Comparison of Psilocybin and LSD Sessions Across Two Controlled Settings

Repository for Publications and Research Data (ETH Zurich) April 30, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

Objectives: For English, the validated part of Psychedelic Experience Scale (PES48) is a four-factor structure called the Mystical Experience Questionnaire (MEQ30). The other validated part of the PES48 consists of four more factors: two more mystical factors (paradoxicality and connectedness, which together with the MEQ30 form the MEQ40), and two more non-mystical factors (visual experience...

Acute Cardiovascular Effects of Psilocybin: A Pooled Analysis of 14 Studies with Safety Recommendations

medRxiv Preprint Server April 28, 2026 Sandeep M. Nayak, Nathan D. Sepeda, Matthew Nielsen Dick et al. preprint

Background Psilocybin has increasingly been studied as a therapeutic for psychiatric and neurologic conditions, yet comprehensive cardiovascular safety data are limited. Current trials often exclude individuals with blood pressure ≥140/90 mmHg, criteria established conservatively without robust empirical support.

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...

Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness—a psychometric analysis using the PES100 in controlled psychedelic studies

Religion Brain & Behavior March 31, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

Mystical dynamics—the notion that mystical oneness may unfold involving ego disintegration, renewal, and luminous light—has been discussed anecdotally by psychedelic researchers and therapists but has not yet been empirically examined in controlled settings. This study investigated the occurrence and dose-dependency of mystical dynamics in healthy participants after administration of...

Trip sitting or just sitting? Session facilitators substantially influence psychedelic experiences in clinical trials but not in healthy ones

Psychiatry Research February 13, 2026 Sean P. Goldy, Nathan D. Sepeda, Samantha Hilbert et al. 1 citation

Psychedelics' characteristic acute subjective effects predict therapeutic benefits, such as decreases in depression and anxiety. Thus, optimizing treatment involves better understanding which factors shape subjective effects. Session facilitators, who support participants before, during, and after psychedelic administration sessions, form an important part of the setting of these experiences....

Challenges with clinical trial participants in studies with classical psychedelics: A position statement from the National Network of Depression Centers' task group on psychedelics and related compounds.

Journal of psychopharmacology (Oxford, England) February 5, 2026 Benjamin R. Lewis, Matthew J Reid, Andrew M Novick et al.

Classical psychedelics-a broad class of compounds that include psilocybin, lysergic acid diethylamide, dimethyltryptamine, and mescaline-have shown significant promise for the treatment of mental health conditions in recent clinical trials. Organizations such as the National Network of Depression Centers (NNDCs) can play a pivotal role in uniting researchers and clinicians working in this field...

Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness-a psychometric analysis using the PES100 in controlled psychedelic studies

Repository for Publications and Research Data (ETH Zurich) 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

Mystical dynamics-the notion that mystical oneness may unfold involving ego disintegration, renewal, and luminous light-has been discussed anecdotally by psychedelic researchers and therapists but has not yet been empirically examined in controlled settings. This study investigated the occurrence and dose-dependency of mystical dynamics in healthy participants after administration of...

Roland R. Griffiths, psychopharmacology pioneer: Abuse liability, alcohol, nicotine, caffeine, benzodiazepines, and psychedelics.

Journal of psychopharmacology (Oxford, England) 2026 Jack E Henningfield, Frederick S. Barrett, Suzette M Evans et al.

This review provides an overview of Roland R. Griffiths' history of research, and his mentoring and collaborating approach to science that contributed to his impact in behavioral and neuropsychopharmacology and psychedelic medicines development. The approach was to summarize studies in his major domains of research, including preclinical and clinical abuse liability assessment science, alcohol,...

Considerations and cautions for the integration of psilocybin into routine clinical care: a consensus statement from the US National Network of Depression Centers' Task Group on Psychedelics and Related Compounds

EClinicalMedicine September 24, 2025 Megan Hosein, Matthew J Reid, Sarah A. Walser et al. 5 citations

The potential for psilocybin, and other psychedelic drugs, to fulfil a much needed and potentially transformative class of psychiatric treatments has garnered significant attention. Consequently, there has been a great deal of interest and investment in accelerating its development and potential implementation in routine clinical practice. However, the expanding scope of scientific discovery,...

Five-year outcomes of psilocybin-assisted therapy for Major Depressive Disorder

Journal of Psychedelic Studies September 4, 2025 Alan K. Davis, Meghan DellaCrosse, Nathan D. Sepeda et al. 4 citations

Abstract Background Major Depressive Disorder (MDD) is a leading cause of disability and economic loss, with high recurrence and treatment resistance. Psilocybin-assisted therapy (PAT) shows promise in reducing depressive symptoms, but long-term effects are unknown. We aimed to determine the long-term safety and efficacy of PAT for MDD over a five-year follow-up period. Methods Individuals who...

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...

Psychedelic risks and benefits: A cross-sectional survey study.

Journal of psychopharmacology (Oxford, England) May 1, 2025 Sean P. Goldy, Benjamin A Du, Julia S Rohde et al. 15 citations

As classic psychedelics' therapeutic potential is studied and their popularity continues to rise, it is important to establish their relative risks and benefits. Previous surveys have tended to use convenience sampling on social media, select participants who have had either extremely positive or negative effects, and have not compared the risk/benefit profile of psychedelics to other...

Visual Hallucinations in Serotonergic Psychedelics and Lewy Body Diseases

Schizophrenia Bulletin April 17, 2025 Nathan H. Heller, Frederick S. Barrett, Tobias Buchborn et al. 3 citations

Abstract Background and Hypothesis Visual hallucinations (VH) are a core symptom of both Lewy body diseases (LBDs; eg, Parkinson’s disease and dementia with Lewy bodies) and serotonergic psychedelics (SPs; eg, psilocybin and mescaline). While these conditions differ in etiology, overlapping phenomenology, and neural mechanisms suggest shared pathways. This review explores similarities and...

Psychedelics Align Brain Activity with Context

bioRxiv (Cold Spring Harbor Laboratory) March 11, 2025 Devon Stoliker, Leonardo Novelli, Moein Khajehnejad et al. 8 citations preprint

Abstract Psychedelics can profoundly alter consciousness by reorganising brain connectivity; however, their effects are contextsensitive. To understand how this reorganisation depends on the context, we collected and comprehensively analysed the largest psychedelic neuroimaging dataset to date. Sixty-two adults were scanned with functional MRI and EEG during rest and naturalistic stimuli...

A Field-Wide Review and Analysis of Study Materials Used in Psilocybin Trials: Assessment of Two Decades of Research

Psychedelic Medicine January 20, 2025 Marianna Graziosi, Gabrielle Agin-Liebes, Mary P Cosimano et al. 9 citations

Introduction: Serotonergic psychedelics, serotonin 2A receptor agonists such as psilocybin that can result in substantially altered states of consciousness, are used in recreational and research settings. The safety of psychedelic experiences in research settings is supported by controlled physical environments, presence of clinical and medical staff to address emergent issues, screening for...

Development of the Japanese version of the Challenging Experience Questionnaire

Neuropsychopharmacology Reports November 8, 2024 Hideaki Tani, Kengo Yonezawa, Keisuke Kusudo et al. 1 citation

Abstract Introduction The therapeutic potential of psychedelics for various mental disorders has gained significant interest. Previous studies have highlighted that psychedelics induce psychoactive effects, including challenging aspects of experiences. These experiences are assessed using the Challenging Experience Questionnaire (CEQ), yet its Japanese version has been unavailable. This study...

Effects of Savoring Meditation on Positive Emotions and Pain-Related Brain Function: A Mechanistic Randomized Controlled Trial in People With Rheumatoid Arthritis.

The journal of pain July 1, 2024 Patrick H. Finan, Carly Hunt, Michael L. Keaser et al. 18 citations

Positive emotions are a promising target for intervention in chronic pain, but mixed findings across trials to date suggest that existing interventions may not be optimized to efficiently engage the target. The aim of the current pilot mechanistic randomized controlled trial was to test the effects of a positive emotion-enhancing intervention called Savoring Meditation on pain-related neural...

The therapeutic alliance between study participants and intervention facilitators is associated with acute effects and clinical outcomes in a psilocybin-assisted therapy trial for major depressive disorder

PLoS One March 14, 2024 Adam W. Levin, Rafaelle Lancelotta, Nathan D. Sepeda et al. 65 citations

We examined if the therapeutic alliance between study participants and intervention facilitators in a psilocybin-assisted therapy (PAT) trial changed over time and whether there were relationships between alliance, acute psilocybin experiences, and depression outcomes. In a randomized, waiting list-controlled clinical trial for major depressive disorder in adults ( N = 24), participants were...

Unique effects of sedatives, dissociatives, psychedelics, stimulants, and cannabinoids on episodic memory: A review and reanalysis of acute drug effects on recollection, familiarity, and metamemory.

Psychological review March 1, 2024 Manoj K. Doss, Jason Samaha, Frederick S. Barrett et al. 24 citations

Despite distinct classes of psychoactive drugs producing putatively unique states of consciousness, there is surprising overlap in terms of their effects on episodic memory and cognition more generally. Episodic memory is supported by multiple subprocesses that have been mostly overlooked in psychopharmacology and could differentiate drug classes. Here, we reanalyzed episodic memory confidence...

Impact of Psilocybin on Peripheral Cytokine Production

Psychedelic Medicine February 28, 2024 Dana D. DiRenzo, Jamie Perin, Erika Darrah et al. 4 citations

This preliminary study suggests that a transient increase in cytokine production ≤1-week postpsilocybin may be found, although not consistently across patient populations. More broadly, peripheral cytokine production is possibly altered by psilocybin administration. ClinicalTrials.gov Identifier: NCT01988311.