John W Smallridge - The Consciousness Library

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [ 18 F]FDG-PET study

Universität Zürich, ZORA June 1, 2026 Klemens Egger, Robert Bozsak, Helena Aicher et al.

Classical psychedelics such as N,N -dimethyltryptamine (DMT) modulate consciousness via serotonergic receptor agonism, and are increasingly investigated for their psychotherapeutic potential. When combined with the monoamine oxidase A (MAO-A) inhibitor harmine—mimicking the pharmacological profile of ayahuasca—oral DMT induces a psychedelic experience lasting 4–5 h. While some neuroimaging...

DOI: 10.5167/uzh-434709 Harmine Placebo Neuroimaging Metabolite +9

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [18F]FDG-PET study.

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism June 1, 2026 Klemens Egger, Robert Bozsak, Helena Aicher et al.

Classical psychedelics such as N,N-dimethyltryptamine (DMT) modulate consciousness via serotonergic receptor agonism, and are increasingly investigated for their psychotherapeutic potential. When combined with the monoamine oxidase A (MAO-A) inhibitor harmine-mimicking the pharmacological profile of ayahuasca-oral DMT induces a psychedelic experience lasting 4-5 h. While some neuroimaging...

DOI: 10.1177/0271678x261454172 Full text DMT Fdg-PET Glucose metabolism Harmine +2

Psilocybin-induced alterations in EEG power, connectivity and network dynamics in healthy subjects: Correlations with subjective experience and implications for therapeutic applications

Progress in Neuro-psychopharmacology and Biological Psychiatry 2026 Cheng-Teng Ip, Sebastian Olbrich, Mateo de Bardeci et al. 1 citation

BACKGROUND: Recent advancements in psychedelic research have highlighted psilocybin's potential therapeutic benefits for various mental disorders. Understanding its effects on brain function and identifying predictors of individual responses are essential for developing effective treatments. METHODS: This double-blind, randomized, crossover, and placebo-controlled study enrolled 25 healthy...

DOI: 10.1016/j.pnpbp.2026.111626 Electroencephalography Dynamics music Neurophysiology Artificial neural network +2

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [¹⁸F]FDG-PET study

Repository for Publications and Research Data (ETH Zurich) 2026 Klemens Egger, Robert Bozsak, Helena Aicher et al.

Classical psychedelics such as N,N-dimethyltryptamine (DMT) modulate consciousness via serotonergic receptor agonism, and are increasingly investigated for their psychotherapeutic potential. When combined with the monoamine oxidase A (MAO-A) inhibitor harmine—mimicking the pharmacological profile of ayahuasca—oral DMT induces a psychedelic experience lasting 4–5 h. While some neuroimaging...

DOI: 10.3929/ethz-c-000801722 Harmine Placebo Neuroimaging Metabolite +9

Population pharmacokinetic-pharmacodynamic modeling of co-administered N,N-dimethyltryptamine and harmine in healthy subjects.

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie July 9, 2025 Angela Äbelö, John W Smallridge, Robin von Rotz et al. 3 citations

N,N-dimethyltryptamine (DMT) is a psychedelic compound commonly co-administered with the monoamine oxidase inhibitor harmine in ayahuasca-inspired formulations. However, the impact of harmine on DMT pharmacokinetics (PK) and pharmacodynamics (PD) remains insufficiently characterized. In this single-blind, randomized, two-arm, factorial, dose-finding study, 16 healthy participants (9 males, 7...

DOI: 10.1016/j.biopha.2025.118329 Full text Pharmacodynamics Pharmacokinetics Psychedelics Harmine-DMT Interaction Alter +10

Examining the pharmacokinetic and pharmacodynamic interaction of N,N-dimethyltryptamine and harmine in healthy volunteers: Α factorial dose-escalation study.

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie March 1, 2025 Klemens Egger, Javier Jareño Redondo, Jovin Müller et al. 14 citations

Ayahuasca, a traditional psychoactive Amazonian brew, usually contains N,N-dimethyltryptamine (DMT) and β-carboline (harmine, harmaline, tetrahydroharmine) monoamine oxidase inhibitors. However, the pharmacological interactions between these compounds remain incompletely understood. In this study, we developed an ayahuasca-inspired formulation containing DMT and harmine, aiming to...

DOI: 10.1016/j.biopha.2025.117908 Full text DMT Ayahuasca pharmahuasca Harmine Pharmacokinetics +5

Meditating on psychedelics. A randomized placebo-controlled study of DMT and harmine in a mindfulness retreat

Journal of Psychopharmacology September 27, 2024 Daniel Meling, Klemens Egger, Jovin Mueller et al. 15 citations

Background: In recent years, both meditation and psychedelics have attracted rapidly increasing scientific interest. While the current state of evidence suggests the promising potential of psychedelics, such as psilocybin, to enhance meditative training, it remains equivocal whether these effects are specifically bound to psilocybin or if other classical psychedelics might show synergistic...

DOI: 10.1177/02698811241282637 Ayahuasca Meditation Mindfulness Psilocybin +4

The influence of psilocybin on subconscious and conscious emotional learning

iScience May 19, 2024 Andres Ort, John W Smallridge, Erich Seifritz et al. 1 citation

Serotonergic psychedelics hold promise as a treatment modality for various psychiatric disorders and are currently applied in psychedelic-assisted psychotherapy. We investigated the learning effects of the serotonin receptor agonist psilocybin in a probabilistic cue-reward task with emotional cues in the form of neutral or fearful faces, presented either consciously or subconsciously. This...

DOI: 10.1016/j.isci.2024.110034 Psilocybin Subconscious Cognitive science

TMS-EEG and resting-state EEG applied to altered states of consciousness: oscillations, complexity, and phenomenology.

iScience May 19, 2023 Andres Ort, John W Smallridge, Simone Sarasso et al. 47 citations

Exploring the neurobiology of the profound changes in consciousness induced by classical psychedelic drugs may require novel neuroimaging methods. Serotonergic psychedelic drugs such as psilocybin produce states of increased sensory-emotional awareness and arousal, accompanied by increased spontaneous electroencephalographic (EEG) signal diversity. By directly stimulating cortical tissue, the...

DOI: 10.1016/j.isci.2023.106589 Full text Psilocybin Medical imaging Pharmacology Neuroscience clinical neuroscience +6

Classic Psychedelic Drugs: Update on Biological Mechanisms

Pharmacopsychiatry January 25, 2022 John W Smallridge, Franz X. Vollenweider 107 citations

Abstract Renewed interest in the effects of psychedelics in the treatment of psychiatric disorders warrants a better understanding of the neurobiological mechanisms underlying the effects of these substances. During the past two decades, state-of-the-art studies of animals and humans have yielded new important insights into the molecular, cellular, and systems-level actions of psychedelic...

DOI: 10.1055/a-1721-2914 Full text Psychedelics Brain chemistry Consciousness Mental health

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