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Bagdasarian FA, Hansen HD, Chen J, Yoo CH, Placzek MS, Hooker JM, Wey HY. Acute Effects of Hallucinogens on Functional Connectivity: Psilocybin and Salvinorin-A. ACS Chem Neurosci 2024; 15:2654-2661. [PMID: 38916752 DOI: 10.1021/acschemneuro.4c00245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024] Open
Abstract
The extent of changes in functional connectivity (FC) within functional networks as a common feature across hallucinogenic drug classes is under-explored. This work utilized fMRI to assess the dissociative hallucinogens Psilocybin, a classical serotonergic psychedelic, and Salvinorin-A, a kappa-opioid receptor (KOR) agonist, on resting-state FC in nonhuman primates. We highlight overlapping and differing influence of these substances on FC relative to the thalamus, claustrum, prefrontal cortex (PFC), default mode network (DMN), and DMN subcomponents. Analysis was conducted on a within-subject basis. Findings support the cortico-claustro-cortical network model for probing functional effects of hallucinogens regardless of serotonergic potential, with a potential key paradigm centered around the claustrum, PFC, anterior cingulate cortices (ACC), and angular gyrus relationship. Thalamo-cortical networks are implicated but appear dependent on 5-HT2AR activation. Acute desynchronization relative to the DMN for both drugs was also shown. Our findings provide a framework to understand broader mechanisms at which hallucinogens in differing classes may impact subjects regardless of the target receptor.
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Affiliation(s)
- Frederick A Bagdasarian
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
| | - Hanne D Hansen
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen DK-2100, Denmark
| | - Jingyuan Chen
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
| | - Chi-Hyeon Yoo
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
| | - Michael S Placzek
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
| | - Jacob M Hooker
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Center for the Neuroscience of Psychedelics, Charlestown, Massachusetts 02129, United States
| | - Hsiao-Ying Wey
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129-2020, United States
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Center for the Neuroscience of Psychedelics, Charlestown, Massachusetts 02129, United States
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Mitchell JM, Anderson BT. Psychedelic therapies reconsidered: compounds, clinical indications, and cautious optimism. Neuropsychopharmacology 2024; 49:96-103. [PMID: 37479859 PMCID: PMC10700471 DOI: 10.1038/s41386-023-01656-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/05/2023] [Accepted: 07/06/2023] [Indexed: 07/23/2023]
Abstract
The clinical investigation of psychedelic medicines has blossomed over the last 5 years. Data from a Phase 3 industry trial and a multicenter Phase 2 industry trial, in addition to multiple early phase investigator-initiated and industry trials, have now been published in peer-reviewed journals. This narrative review summarizes both the recent data and the current clinical trials that are being conducted with various classes of "psyche-manifesting" substances, which may prove beneficial in the treatment of a broad range of conditions. Methodological considerations, unique challenges, and next steps for research are discussed in keeping with the uniquely "experiential" nature of these therapies.
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Affiliation(s)
- Jennifer M Mitchell
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA.
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, CA, USA.
- Department of Veterans Affairs, Research Service, San Francisco VA Medical Center, San Francisco, CA, USA.
- Berkeley Center for the Science of Psychedelics, University of California Berkeley, Berkeley, CA, USA.
| | - Brian T Anderson
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, CA, USA
- Berkeley Center for the Science of Psychedelics, University of California Berkeley, Berkeley, CA, USA
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3
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Nutt DJ, Peill JM, Weiss B, Godfrey K, Carhart-Harris RL, Erritzoe D. Psilocybin and Other Classic Psychedelics in Depression. Curr Top Behav Neurosci 2023. [PMID: 37955822 DOI: 10.1007/7854_2023_451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Psychedelic drugs such as psilocybin and ketamine are returning to clinical research and intervention across several disorders including the treatment of depression. This chapter focusses on psychedelics that specifically target the 5-HT2A receptor such as psilocybin and DMT. These produce plasma-concentration related psychological effects such as hallucinations and out of body experiences, insightful and emotional breakthroughs as well as mystical-type experiences. When coupled with psychological support, effects can produce a rapid improvement in mood among people with depression that can last for months. In this chapter, we summarise the scientific studies to date that explore the use of psychedelics in depressed individuals, highlighting key clinical, psychological and neuroimaging features of psychedelics that may account for their therapeutic effects. These include alterations in brain entropy that disrupt fixed negative ruminations, a period of post-treatment increased cognitive flexibility, and changes in self-referential psychological processes. Finally, we propose that the brain mechanisms underlying the therapeutic effect of serotonergic psychedelics might be distinct from those underlying classical serotonin reuptake-blocking antidepressants.
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Affiliation(s)
- D J Nutt
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK.
| | - J M Peill
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - B Weiss
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - K Godfrey
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - R L Carhart-Harris
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
- Psychedelics Division, Neuroscape, University of California San Francisco, San Francisco, CA, USA
| | - D Erritzoe
- Centres for Neuropsychopharmacology & Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
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4
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Yarur HE, Casello SM, Tsai VS, Enriquez-Traba J, Kore R, Wang H, Arenivar M, Tejeda HA. Dynorphin / kappa-opioid receptor regulation of excitation-inhibition balance toggles afferent control of prefrontal cortical circuits in a pathway-specific manner. Mol Psychiatry 2023; 28:4801-4813. [PMID: 37644172 PMCID: PMC10914606 DOI: 10.1038/s41380-023-02226-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/31/2023]
Abstract
The medial prefrontal cortex (mPFC) controls behavior via connections with limbic excitatory afferents that engage various inhibitory motifs to shape mPFC circuit function. The dynorphin (Dyn) / kappa-opioid receptor (KOR) system is highly enriched in the mPFC, and its dysregulation is implicated in neuropsychiatric disorders. However, it is unclear how the Dyn / KOR system modulates excitatory and inhibitory circuits that are integral for mPFC information processing and behavioral control. Here, we provide a circuit-based framework wherein mPFC Dyn / KOR signaling regulates excitation-inhibition balance by toggling which afferents drive mPFC neurons. Dyn / KOR regulation of afferent inputs is pathway-specific. Dyn acting on presynaptic KORs inhibits glutamate release from afferent inputs to the mPFC, including the basolateral amygdala (BLA), paraventricular nucleus of the thalamus, and contralateral cortex. The majority of excitatory synapses to mPFC neurons, including those from the ventral hippocampus (VH), do not express presynaptic KOR, rendering them insensitive to Dyn / KOR modulation. Dyn / KOR signaling also suppresses afferent-driven recruitment of specific inhibitory sub-networks, providing a basis for Dyn to disinhibit mPFC circuits. Specifically, Dyn / KOR signaling preferentially suppresses SST interneuron- relative to PV interneuron-mediated inhibition. Selective KOR action on afferents or within mPFC microcircuits gates how distinct limbic inputs drive spiking in mPFC neurons. Presynaptic Dyn / KOR signaling decreases KOR-positive input-driven (e.g. BLA) spiking of mPFC neurons. In contrast, KOR-negative input recruitment of mPFC neurons is enhanced by Dyn / KOR signaling via suppression of mPFC inhibitory microcircuits. Thus, by acting on distinct circuit elements, Dyn / KOR signaling shifts KOR-positive and negative afferent control of mPFC circuits, providing mechanistic insights into the role of neuropeptides in shaping mPFC function. Together, these findings highlight the utility of targeting the mPFC Dyn / KOR system as a means to treat neuropsychiatric disorders characterized by dysregulation in mPFC integration of long-range afferents with local inhibitory microcircuits.
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Affiliation(s)
- Hector E Yarur
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Sanne M Casello
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Valerie S Tsai
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Juan Enriquez-Traba
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
- NIH Graduate Partnership Program, Washington, DC, USA
| | - Rufina Kore
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Huikun Wang
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Miguel Arenivar
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
- NIH Graduate Partnership Program, Washington, DC, USA
| | - Hugo A Tejeda
- Unit on Neuromodulation and Synaptic Integration, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.
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Luppi AI, Hansen JY, Adapa R, Carhart-Harris RL, Roseman L, Timmermann C, Golkowski D, Ranft A, Ilg R, Jordan D, Bonhomme V, Vanhaudenhuyse A, Demertzi A, Jaquet O, Bahri MA, Alnagger NL, Cardone P, Peattie AR, Manktelow AE, de Araujo DB, Sensi SL, Owen AM, Naci L, Menon DK, Misic B, Stamatakis EA. In vivo mapping of pharmacologically induced functional reorganization onto the human brain's neurotransmitter landscape. SCIENCE ADVANCES 2023; 9:eadf8332. [PMID: 37315149 PMCID: PMC10266734 DOI: 10.1126/sciadv.adf8332] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/10/2023] [Indexed: 06/16/2023]
Abstract
To understand how pharmacological interventions can exert their powerful effects on brain function, we need to understand how they engage the brain's rich neurotransmitter landscape. Here, we bridge microscale molecular chemoarchitecture and pharmacologically induced macroscale functional reorganization, by relating the regional distribution of 19 neurotransmitter receptors and transporters obtained from positron emission tomography, and the regional changes in functional magnetic resonance imaging connectivity induced by 10 different mind-altering drugs: propofol, sevoflurane, ketamine, lysergic acid diethylamide (LSD), psilocybin, N,N-Dimethyltryptamine (DMT), ayahuasca, 3,4-methylenedioxymethamphetamine (MDMA), modafinil, and methylphenidate. Our results reveal a many-to-many mapping between psychoactive drugs' effects on brain function and multiple neurotransmitter systems. The effects of both anesthetics and psychedelics on brain function are organized along hierarchical gradients of brain structure and function. Last, we show that regional co-susceptibility to pharmacological interventions recapitulates co-susceptibility to disorder-induced structural alterations. Collectively, these results highlight rich statistical patterns relating molecular chemoarchitecture and drug-induced reorganization of the brain's functional architecture.
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Affiliation(s)
- Andrea I. Luppi
- Division of Anaesthesia, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Leverhulme Centre for the Future of Intelligence, University of Cambridge, Cambridge, UK
- The Alan Turing Institute, London, UK
- McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Justine Y. Hansen
- McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Ram Adapa
- Division of Anaesthesia, University of Cambridge, Cambridge, UK
| | - Robin L. Carhart-Harris
- Psychedelics Division - Neuroscape, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Leor Roseman
- Center for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, UK
| | - Christopher Timmermann
- Center for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, UK
| | - Daniel Golkowski
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, München, Germany
| | - Andreas Ranft
- School of Medicine, Department of Anesthesiology and Intensive Care, Technical University of Munich, Munich, Germany
| | - Rüdiger Ilg
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, München, Germany
- Department of Neurology, Asklepios Clinic, Bad Tölz, Germany
| | - Denis Jordan
- Department of Anaesthesiology and Intensive Care Medicine, Klinikum rechts der Isar, Technical University Munich, München, Germany
- University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - Vincent Bonhomme
- Department of Anesthesia and Intensive Care Medicine, Liege University Hospital, Liege, Belgium
- Anesthesia and Perioperative Neuroscience Laboratory, GIGA-Consciousness Thematic Unit, GIGA-Research, Liege University, Liege, Belgium
| | - Audrey Vanhaudenhuyse
- Department of Anesthesia and Intensive Care Medicine, Liege University Hospital, Liege, Belgium
| | - Athena Demertzi
- GIGA-Cyclotron Research Centre-In Vivo Imaging, University of Liege, Liege, Belgium
| | - Oceane Jaquet
- Department of Anesthesia and Intensive Care Medicine, Liege University Hospital, Liege, Belgium
| | - Mohamed Ali Bahri
- GIGA-Cyclotron Research Centre-In Vivo Imaging, University of Liege, Liege, Belgium
| | - Naji L. N. Alnagger
- Department of Anesthesia and Intensive Care Medicine, Liege University Hospital, Liege, Belgium
| | - Paolo Cardone
- Department of Anesthesia and Intensive Care Medicine, Liege University Hospital, Liege, Belgium
| | - Alexander R. D. Peattie
- Division of Anaesthesia, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | | | | | - Stefano L. Sensi
- Department of Neuroscience and Imaging and Clinical Science, Center for Advanced Studies and Technology, Institute for Advanced Biomedical Technologies, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
- Institute for Memory Impairments and Neurological Disorders, University of California-Irvine, Irvine, CA, USA
| | - Adrian M. Owen
- Department of Psychology and Department of Physiology and Pharmacology, Western Institute for Neuroscience (WIN), Western University, London, ON, Canada
| | - Lorina Naci
- Trinity College Institute of Neuroscience, School of Psychology, Trinity College Dublin, Dublin, Ireland
| | - David K. Menon
- Division of Anaesthesia, University of Cambridge, Cambridge, UK
- Wolfon Brain Imaging Centre, University of Cambridge, Cambridge, UK
| | - Bratislav Misic
- McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Emmanuel A. Stamatakis
- Division of Anaesthesia, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Michael P, Luke D, Robinson O. An encounter with the self: A thematic and content analysis of the DMT experience from a naturalistic field study. Front Psychol 2023; 14:1083356. [PMID: 37051610 PMCID: PMC10083325 DOI: 10.3389/fpsyg.2023.1083356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/22/2023] [Indexed: 03/28/2023] Open
Abstract
IntroductionN,N-Dimethyltryptamine (DMT) is an endogenous serotonergic psychedelic capable of producing radical shifts in an experience that have significant implications for consciousness and its neural correlates, especially given the “disconnected consciousness” suggested by the “breakthrough” DMT state. Its increasing usage and clinical trial indicate the growing importance of a thorough elucidation of the experience's qualitative content, over and above the phenomenological structure. This is particularly in light of the intensely pervasive effects of DMT occasions in all dimensions of the self, which are often ontologically challenging yet potentially transformative.MethodsThis is the second report on the first naturalistic field study of DMT use exploring its qualitative analysis. Screened, healthy, anonymized, and experienced DMT users were observed during their non-clinical use of the drug at home (40–75-mg inhaled). In-depth semi-structured interviews, inspired by the micro-phenomenological technique, were employed immediately after their experience. This study reports on the thematic and content analysis of one major domain of the breakthrough experiences elicited, the “self”; where analyses of the “other” were previously reported. A total of 36 post-DMT experience interviews with mostly Caucasian (83%) men (eight women) of a mean of 37 years were predominantly inductively coded.ResultsInvariably, profound and highly intense experiences occurred. The first overarching category comprised the onset of effects, encompassing super-ordinate themes including sensory, emotion and body, and space-time shifts; the second category comprised bodily effects, encompassing themes including pleasurable, neutral/both, and uncomfortable; the third category comprised the sensorial effects, encompassing open-eye, visual, and cross-modal and other; the fourth comprised the psychological effects, encompassing memory and language, awareness and sense of self, and time distortions; and the fifth comprised the emotional effects, encompassing positive, neither/both, and challenging experiences. Many further subthemes also illuminate the rich content of the DMT experience.DiscussionThe present study provides a systematic and nuanced analysis of the content of the breakthrough DMT state pertaining to one's personal and self-referential experiences of the body, senses, psychology, and emotions. The resonances both with previous DMT studies and other types of extraordinary experiences, such as the alien abduction, shamanic and near-death experiences, are also elaborated upon. Putative neural mechanisms and their promise as a psychotherapeutic agent, especially owing to deep emotional impact, are discussed.
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Affiliation(s)
- Pascal Michael
- Centre for Mental Health, School of Human Sciences, Old Royal Naval College, University of Greenwich, London, United Kingdom
| | - David Luke
- Centre for Mental Health, School of Human Sciences, Old Royal Naval College, University of Greenwich, London, United Kingdom
- Department of Brain Sciences, Faculty of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
| | - Oliver Robinson
- Centre for Mental Health, School of Human Sciences, Old Royal Naval College, University of Greenwich, London, United Kingdom
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7
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Gattuso JJ, Perkins D, Ruffell S, Lawrence AJ, Hoyer D, Jacobson LH, Timmermann C, Castle D, Rossell SL, Downey LA, Pagni BA, Galvão-Coelho NL, Nutt D, Sarris J. Default Mode Network Modulation by Psychedelics: A Systematic Review. Int J Neuropsychopharmacol 2023; 26:155-188. [PMID: 36272145 PMCID: PMC10032309 DOI: 10.1093/ijnp/pyac074] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterized by increased temporal coherence at rest have been termed the Default Mode Network (DMN). The DMN has been the focus of numerous studies assessing its role in self-referencing, mind wandering, and autobiographical memories. Altered connectivity in the DMN has been associated with a range of neuropsychiatric conditions such as depression, anxiety, post-traumatic stress disorder, attention deficit hyperactive disorder, schizophrenia, and obsessive-compulsive disorder. To date, several studies have investigated how psychedelics modulate this network, but no comprehensive review, to our knowledge, has critically evaluated how major classical psychedelic agents-lysergic acid diethylamide, psilocybin, and ayahuasca-modulate the DMN. Here we present a systematic review of the knowledge base. Across psychedelics there is consistent acute disruption in resting state connectivity within the DMN and increased functional connectivity between canonical resting-state networks. Various models have been proposed to explain the cognitive mechanisms of psychedelics, and in one model DMN modulation is a central axiom. Although the DMN is consistently implicated in psychedelic studies, it is unclear how central the DMN is to the therapeutic potential of classical psychedelic agents. This article aims to provide the field with a comprehensive overview that can propel future research in such a way as to elucidate the neurocognitive mechanisms of psychedelics.
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Affiliation(s)
- James J Gattuso
- MDHS, University of Melbourne, Parkville, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Daniel Perkins
- Psychae Institute, Melbourne, Victoria, Australia
- MDHS, University of Melbourne, Parkville, Victoria, Australia
- School of Social and Political Science, University of Melbourne, Australia
- Centre for Mental Health, Swinburne University, Hawthorn, Victoria, Australia
| | - Simon Ruffell
- The Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Andrew J Lawrence
- Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Daniel Hoyer
- MDHS, University of Melbourne, Parkville, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
- The Scripps Research Institute, Department of Molecular Medicine, La Jolla, California, USA
| | - Laura H Jacobson
- MDHS, University of Melbourne, Parkville, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | | | - David Castle
- Department of Psychiatry, University of Toronto, Canada
| | - Susan L Rossell
- Centre for Mental Health, Swinburne University, Hawthorn, Victoria, Australia
| | - Luke A Downey
- Centre for Human Psychopharmacology, Swinburne University, Hawthorn, Victoria, Australia
| | - Broc A Pagni
- College of Health Solutions, Arizona State University, Tempe, Arizona, USA
| | - Nicole L Galvão-Coelho
- Department of Physiology and Behavior, Universidade Federal do Rio Grande do Norte, Brazil
- NICM Health Research Institute, Western Sydney University, Westmead, New South Wales, Australia
| | - David Nutt
- Centre for Psychedelic Research, Division of Psychiatry, Imperial College London, UK
| | - Jerome Sarris
- Psychae Institute, Melbourne, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
- NICM Health Research Institute, Western Sydney University, Westmead, New South Wales, Australia
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8
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A complex systems perspective on psychedelic brain action. Trends Cogn Sci 2023; 27:433-445. [PMID: 36740518 DOI: 10.1016/j.tics.2023.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 01/10/2023] [Accepted: 01/17/2023] [Indexed: 02/05/2023]
Abstract
Recent findings suggesting the potential transdiagnostic efficacy of psychedelic-assisted therapy have fostered the need to deepen our understanding of psychedelic brain action. Functional neuroimaging investigations have found that psychedelics reduce the functional segregation of large-scale brain networks. However, beyond this general trend, findings have been largely inconsistent. We argue here that a perspective based on complexity science that foregrounds the distributed, interactional, and dynamic nature of brain function may render these inconsistencies intelligible. We propose that psychedelics induce a mode of brain function that is more dynamically flexible, diverse, integrated, and tuned for information sharing, consistent with greater criticality. This 'meta' perspective has the potential to unify past findings and guide intuitions toward compelling mechanistic models.
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9
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Nutt D, Spriggs M, Erritzoe D. Psychedelics therapeutics: What we know, what we think, and what we need to research. Neuropharmacology 2023; 223:109257. [PMID: 36179919 DOI: 10.1016/j.neuropharm.2022.109257] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/07/2022] [Accepted: 09/11/2022] [Indexed: 12/14/2022]
Abstract
Psychedelic therapy is perhaps the most exciting new development in psychiatry. Not only does it offer a radical new approach to treatment where mainstream approaches have proven ineffective, but the growing evidence for transdiagnostic efficacy is eliciting a re-think of current diagnostic and symptom-specific approaches to psychiatry. This excitement has led to a massive investment in this field with many tens of new pharmaceutical companies being set up to research the effects of known psychedelics and develop new patentable molecules. Whilst this enthusiasm is to be welcomed, it is important that new research is properly grounded in established facts and reflects current knowledge. In this commentary we lay out the knowledge framework that should be taken into account by all innovative researchers in this field.
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Affiliation(s)
- David Nutt
- Centres for Neuropsychopharmacology and Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - Meg Spriggs
- Centres for Neuropsychopharmacology and Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK
| | - David Erritzoe
- Centres for Neuropsychopharmacology and Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK.
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10
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Rosenblat JD, Husain MI, Lee Y, McIntyre RS, Mansur RB, Castle D, Offman H, Parikh SV, Frey BN, Schaffer A, Greenway KT, Garel N, Beaulieu S, Kennedy SH, Lam RW, Milev R, Ravindran AV, Tourjman V, Ameringen MV, Yatham LN, Taylor V. The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: Serotonergic Psychedelic Treatments for Major Depressive Disorder. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2023; 68:5-21. [PMID: 35975555 PMCID: PMC9720483 DOI: 10.1177/07067437221111371] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Serotonergic psychedelics are re-emerging as potential novel treatments for several psychiatric disorders including major depressive disorder. The Canadian Network for Mood and Anxiety Treatments (CANMAT) convened a task force to review the evidence and provide a consensus recommendation for the clinical use of psychedelic treatments for major depressive disorder. METHODS A systematic review was conducted to identify contemporary clinical trials of serotonergic psychedelics for the treatment of major depressive disorder and cancer-related depression. Studies published between January 1990 and July 2021 were identified using combinations of search terms, inspection of bibliographies and review of other psychedelic reviews and consensus statements. The levels of evidence for efficacy were graded according to the Canadian Network for Mood and Anxiety Treatments criteria. RESULTS Only psilocybin and ayahuasca have contemporary clinical trials evaluating antidepressant effects. Two pilot studies showed preliminary positive effects of single-dose ayahuasca for treatment-resistant depression (Level 3 evidence). Small randomized controlled trials of psilocybin combined with psychotherapy showed superiority to waitlist controls and comparable efficacy and safety to an active comparator (escitalopram with supportive psychotherapy) in major depressive disorder, with additional randomized controlled trials showing efficacy specifically in cancer-related depression (Level 3 evidence). There was only one open-label trial of psilocybin in treatment-resistant unipolar depression (Level 4 evidence). Small sample sizes and functional unblinding were major limitations in all studies. Adverse events associated with psychedelics, including psychological (e.g., psychotomimetic effects) and physical (e.g., nausea, emesis and headaches) effects, were generally transient. CONCLUSIONS There is currently only low-level evidence to support the efficacy and safety of psychedelics for major depressive disorder. In Canada, as of 2022, psilocybin remains an experimental option that is only available through clinical trials or the special access program. As such, Canadian Network for Mood and Anxiety Treatments considers psilocybin an experimental treatment and recommends its use primarily within clinical trials, or, less commonly, through the special access program in rare, special circumstances.
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Affiliation(s)
- Joshua D. Rosenblat
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - M. Ishrat Husain
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental
Health Research Institute Toronto, Ontario, Canada
| | - Yena Lee
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - Roger S. McIntyre
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - Rodrigo B. Mansur
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - David Castle
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental
Health Research Institute Toronto, Ontario, Canada
| | - Hilary Offman
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Sagar V. Parikh
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Depression Program, Michigan Medicine, University of Michigan, Ann
Arbor, USA
| | - Benicio N. Frey
- Mood Disorders Program, St. Joseph's Healthcare Hamilton, McMaster
University, Psychiatry & Behavioural Neurosciences, Hamilton, Ontario,
Canada
| | - Ayal Schaffer
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Department of Psychiatry, Sunnybrook Health Sciences Centre,
Toronto, Ontario, Canada
| | | | - Nicolas Garel
- McGill University, Psychiatry, Montreal, Quebec, Canada
| | | | - Sidney H. Kennedy
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
| | - Raymond W. Lam
- Department of Psychiatry, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Roumen Milev
- Department of Psychiatry, Providence Care, Queen's University,
Kingston, ON, Canada
| | - Arun V. Ravindran
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Centre for Addiction and Mental Health, Campbell Family Mental
Health Research Institute Toronto, Ontario, Canada
| | - Valerie Tourjman
- Institut universitaire en santé mentale de Montréal, Psychiatry,
Montreal, Quebec, Canada
| | - Michael Van Ameringen
- McMaster University Medical Centre, Anxiety Disorders Clinic,
Hamilton, Ontario, Canada
| | - Lakshmi N. Yatham
- Department of Psychiatry, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Valerie Taylor
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
- Mood Disorders Psychopharmacology Unit,
University Health Network, Toronto, Ontario, Canada
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11
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Dourron HM, Strauss C, Hendricks PS. Self-Entropic Broadening Theory: Toward a New Understanding of Self and Behavior Change Informed by Psychedelics and Psychosis. Pharmacol Rev 2022; 74:982-1027. [DOI: 10.1124/pharmrev.121.000514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 11/22/2022] Open
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12
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Doss MK, Madden MB, Gaddis A, Nebel MB, Griffiths RR, Mathur BN, Barrett FS. Models of psychedelic drug action: modulation of cortical-subcortical circuits. Brain 2022; 145:441-456. [PMID: 34897383 PMCID: PMC9014750 DOI: 10.1093/brain/awab406] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/10/2021] [Accepted: 10/05/2021] [Indexed: 12/15/2022] Open
Abstract
Classic psychedelic drugs such as psilocybin and lysergic acid diethylamide (LSD) have recaptured the imagination of both science and popular culture, and may have efficacy in treating a wide range of psychiatric disorders. Human and animal studies of psychedelic drug action in the brain have demonstrated the involvement of the serotonin 2A (5-HT2A) receptor and the cerebral cortex in acute psychedelic drug action, but different models have evolved to try to explain the impact of 5-HT2A activation on neural systems. Two prominent models of psychedelic drug action (the cortico-striatal thalamo-cortical, or CSTC, model and relaxed beliefs under psychedelics, or REBUS, model) have emphasized the role of different subcortical structures as crucial in mediating psychedelic drug effects. We describe these models and discuss gaps in knowledge, inconsistencies in the literature and extensions of both models. We then introduce a third circuit-level model involving the claustrum, a thin strip of grey matter between the insula and the external capsule that densely expresses 5-HT2A receptors (the cortico-claustro-cortical, or CCC, model). In this model, we propose that the claustrum entrains canonical cortical network states, and that psychedelic drugs disrupt 5-HT2A-mediated network coupling between the claustrum and the cortex, leading to attenuation of canonical cortical networks during psychedelic drug effects. Together, these three models may explain many phenomena of the psychedelic experience, and using this framework, future research may help to delineate the functional specificity of each circuit to the action of both serotonergic and non-serotonergic hallucinogens.
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Affiliation(s)
- Manoj K Doss
- Center for Psychedelic and Consciousness Research, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Maxwell B Madden
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Andrew Gaddis
- Center for Psychedelic and Consciousness Research, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Mary Beth Nebel
- Center for Neurodevelopmental and Imaging Research, Kennedy Krieger Institute, Baltimore, MD, 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Roland R Griffiths
- Center for Psychedelic and Consciousness Research, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Brian N Mathur
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Frederick S Barrett
- Center for Psychedelic and Consciousness Research, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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13
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McCulloch DEW, Madsen MK, Stenbæk DS, Kristiansen S, Ozenne B, Jensen PS, Knudsen GM, Fisher PM. Lasting effects of a single psilocybin dose on resting-state functional connectivity in healthy individuals. J Psychopharmacol 2022; 36:74-84. [PMID: 34189985 PMCID: PMC8801642 DOI: 10.1177/02698811211026454] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND Psilocybin is a psychedelic drug that has shown lasting positive effects on clinical symptoms and self-reported well-being following a single dose. There has been little research into the long-term effects of psilocybin on brain connectivity in humans. AIM Evaluate changes in resting-state functional connectivity (RSFC) at 1 week and 3 months after one psilocybin dose in 10 healthy psychedelic-naïve volunteers and explore associations between change in RSFC and related measures. METHODS Participants received 0.2-0.3 mg/kg psilocybin in a controlled setting. Participants completed resting-state functional magnetic resonance imaging (fMRI) scans at baseline, 1-week and 3-month post-administration and [11C]Cimbi-36 PET scans at baseline and 1 week. We examined changes in within-network, between-network and region-to-region RSFC. We explored associations between changes in RSFC and psilocybin-induced phenomenology as well as changes in psychological measures and neocortex serotonin 2A receptor binding. RESULTS Psilocybin was well tolerated and produced positive changes in well-being. At 1 week only, executive control network (ECN) RSFC was significantly decreased (Cohen's d = -1.73, pFWE = 0.010). We observed no other significant changes in RSFC at 1 week or 3 months, nor changes in region-to-region RSFC. Exploratory analyses indicated that decreased ECN RSFC at 1 week predicted increased mindfulness at 3 months (r = -0.65). CONCLUSIONS These findings in a small cohort indicate that psilocybin affects ECN function within the psychedelic 'afterglow' period. Our findings implicate ECN modulation as mediating psilocybin-induced, long-lasting increases in mindfulness. Although our findings implicate a neural pathway mediating lasting psilocybin effects, it is notable that changes in neuroimaging measures at 3 months, when personality changes are observed, remain to be identified.
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Affiliation(s)
| | - Martin Korsbak Madsen
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark,Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Dea Siggaard Stenbæk
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark,Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Sara Kristiansen
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark
| | - Brice Ozenne
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark,Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Peter Steen Jensen
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark
| | - Gitte Moos Knudsen
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark,Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Patrick MacDonald Fisher
- Neurobiology Research Unit and NeuroPharm, Rigshospitalet, Copenhagen, Denmark,Patrick MacDonald Fisher, Neurobiology Research Unit, Rigshospitalet Building 8057, 8 Inge Lehmanns Vej, Copenhagen 2100, Denmark.
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14
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Kelly JR, Gillan CM, Prenderville J, Kelly C, Harkin A, Clarke G, O'Keane V. Psychedelic Therapy's Transdiagnostic Effects: A Research Domain Criteria (RDoC) Perspective. Front Psychiatry 2021; 12:800072. [PMID: 34975593 PMCID: PMC8718877 DOI: 10.3389/fpsyt.2021.800072] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/19/2021] [Indexed: 12/12/2022] Open
Abstract
Accumulating clinical evidence shows that psychedelic therapy, by synergistically combining psychopharmacology and psychological support, offers a promising transdiagnostic treatment strategy for a range of disorders with restricted and/or maladaptive habitual patterns of emotion, cognition and behavior, notably, depression (MDD), treatment resistant depression (TRD) and addiction disorders, but perhaps also anxiety disorders, obsessive-compulsive disorder (OCD), Post-Traumatic Stress Disorder (PTSD) and eating disorders. Despite the emergent transdiagnostic evidence, the specific clinical dimensions that psychedelics are efficacious for, and associated underlying neurobiological pathways, remain to be well-characterized. To this end, this review focuses on pre-clinical and clinical evidence of the acute and sustained therapeutic potential of psychedelic therapy in the context of a transdiagnostic dimensional systems framework. Focusing on the Research Domain Criteria (RDoC) as a template, we will describe the multimodal mechanisms underlying the transdiagnostic therapeutic effects of psychedelic therapy, traversing molecular, cellular and network levels. These levels will be mapped to the RDoC constructs of negative and positive valence systems, arousal regulation, social processing, cognitive and sensorimotor systems. In summarizing this literature and framing it transdiagnostically, we hope we can assist the field in moving toward a mechanistic understanding of how psychedelics work for patients and eventually toward a precise-personalized psychedelic therapy paradigm.
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Affiliation(s)
- John R. Kelly
- Department of Psychiatry, Trinity College, Dublin, Ireland
- Department of Psychiatry, Tallaght University Hospital, Dublin, Ireland
| | - Claire M. Gillan
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
- School of Psychology, Trinity College, Dublin, Ireland
- Global Brain Health Institute, Trinity College, Dublin, Ireland
| | - Jack Prenderville
- Transpharmation Ireland Ltd, Institute of Neuroscience, Trinity College, Dublin, Ireland
- Discipline of Physiology, School of Medicine, Trinity College, Dublin, Ireland
| | - Clare Kelly
- Department of Psychiatry, Trinity College, Dublin, Ireland
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
- School of Psychology, Trinity College, Dublin, Ireland
| | - Andrew Harkin
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
- School of Pharmacy and Pharmaceutical Sciences, Trinity College, Dublin, Ireland
| | - Gerard Clarke
- Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Veronica O'Keane
- Department of Psychiatry, Trinity College, Dublin, Ireland
- Department of Psychiatry, Tallaght University Hospital, Dublin, Ireland
- Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland
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15
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Michael P, Luke D, Robinson O. An Encounter With the Other: A Thematic and Content Analysis of DMT Experiences From a Naturalistic Field Study. Front Psychol 2021; 12:720717. [PMID: 34975614 PMCID: PMC8716686 DOI: 10.3389/fpsyg.2021.720717] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/15/2021] [Indexed: 12/21/2022] Open
Abstract
Introduction: N,N-dimethyltryptamine (DMT) is an endogenous serotonergic psychedelic capable of producing radical shifts in conscious experience. Increasing trends in its use, as well as new trials administering DMT to patients, indicate the growing importance of a thorough elucidation of the qualitative content, over and above structure, which the drug occasions. This is particularly in light of the hyper-real, otherworldly, and often ontologically challenging yet potentially transformative, nature of the experience, not least encounters with apparently non-self social agents. Laboratory studies have been limited by clinical setting and lacking qualitative analyses of experiential content, while online surveys' limitations lie in retrospective design, uncontrolled use, and both of which not guaranteeing 'breakthrough' experiences, i.e., producing very strong psychoactive effects. Methods: We report on the first naturalistic field study of DMT use including its qualitative analysis. Screened, healthy, anonymised and experienced DMT users were observed during their non-clinical use of the drug at home (40-75 mg inhaled). In-depth semi-structured interviews (inspired by the micro-phenomenological technique) were employed immediately after their experience. This paper reports on the thematic analysis of one major domain of the breakthrough experiences elicited, the 'other'. Thirty-six post-DMT experience interviews with mostly Caucasian (83%) males (eight female) of average 37 years were predominantly inductively coded. Results: Invariably, profound and highly intense experiences occurred. The first overarching category comprised the encounter with other 'beings' (94% of reports), encompassing super-ordinate themes including the entities' role, appearance, demeanour, communication and interaction; while the second overarching category comprised experiences of emerging into other 'worlds' (100% of reports), encompassing super-ordinate themes of the scene, the contents and quality of the immersive spaces. Many further mid-level themes and subthemes also illuminate the rich content of the DMT experience. Discussion: The present study provides a systematic and in-depth analysis of the nuanced content of the otherworldly encounter within the breakthrough DMT experience, as well as elaborating on the resonances both with previous DMT studies focusing on entity encounters and other types of extraordinary experiences entailing such encounters. These include the alien abduction, folkloric, shamanic and near-death experience. Putative neural mechanisms of these features of the DMT experience and its promise as a psychotherapeutic agent are discussed in light of such findings.
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Affiliation(s)
- Pascal Michael
- School of Human Sciences, Old Royal Naval College, University of Greenwich, London, United Kingdom
| | - David Luke
- School of Human Sciences, Old Royal Naval College, University of Greenwich, London, United Kingdom
- Department of Brain Sciences, Faculty of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
| | - Oliver Robinson
- School of Human Sciences, Old Royal Naval College, University of Greenwich, London, United Kingdom
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16
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Psilocybin therapy increases cognitive and neural flexibility in patients with major depressive disorder. Transl Psychiatry 2021; 11:574. [PMID: 34750350 PMCID: PMC8575795 DOI: 10.1038/s41398-021-01706-y] [Citation(s) in RCA: 111] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/14/2021] [Accepted: 10/26/2021] [Indexed: 12/19/2022] Open
Abstract
Psilocybin has shown promise for the treatment of mood disorders, which are often accompanied by cognitive dysfunction including cognitive rigidity. Recent studies have proposed neuropsychoplastogenic effects as mechanisms underlying the enduring therapeutic effects of psilocybin. In an open-label study of 24 patients with major depressive disorder, we tested the enduring effects of psilocybin therapy on cognitive flexibility (perseverative errors on a set-shifting task), neural flexibility (dynamics of functional connectivity or dFC via functional magnetic resonance imaging), and neurometabolite concentrations (via magnetic resonance spectroscopy) in brain regions supporting cognitive flexibility and implicated in acute psilocybin effects (e.g., the anterior cingulate cortex, or ACC). Psilocybin therapy increased cognitive flexibility for at least 4 weeks post-treatment, though these improvements were not correlated with the previously reported antidepressant effects. One week after psilocybin therapy, glutamate and N-acetylaspartate concentrations were decreased in the ACC, and dFC was increased between the ACC and the posterior cingulate cortex (PCC). Surprisingly, greater increases in dFC between the ACC and PCC were associated with less improvement in cognitive flexibility after psilocybin therapy. Connectome-based predictive modeling demonstrated that baseline dFC emanating from the ACC predicted improvements in cognitive flexibility. In these models, greater baseline dFC was associated with better baseline cognitive flexibility but less improvement in cognitive flexibility. These findings suggest a nuanced relationship between cognitive and neural flexibility. Whereas some enduring increases in neural dynamics may allow for shifting out of a maladaptively rigid state, larger persisting increases in neural dynamics may be of less benefit to psilocybin therapy.
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17
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Ona G, Sampedro F, Romero S, Valle M, Camacho V, Migliorelli C, Mañanas MÁ, Antonijoan RM, Puntes M, Coimbra J, Ballester MR, Garrido M, Riba J. The Kappa Opioid Receptor and the Sleep of Reason: Cortico-Subcortical Imbalance Following Salvinorin-A. Int J Neuropsychopharmacol 2021; 25:54-63. [PMID: 34537829 PMCID: PMC8756086 DOI: 10.1093/ijnp/pyab063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 08/25/2021] [Accepted: 09/15/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The mechanisms through which kappa opioid receptor (KOR) agonists induce psychotomimetic effects are largely unknown, although the modulation of this receptor has attracted attention for its clinical use. In this work, we characterize the neuropharmacological effects of salvinorin-A, a highly selective KOR agonist. METHODS Changes in multimodal electroencephalography, single-photon emission computed tomography, and subjective effects following the acute administration of salvinorin-A are reported. The study included 2 sub-studies that employed a double-blind, crossover, randomized, placebo-controlled design. RESULTS The electroencephalography measures showed a marked increase in delta and gamma waves and a decrease in alpha waves while subjects were under the effect of salvinorin-A. Regarding single-photon emission computed tomography measures, significant decreases in regional cerebral blood flow were detected in multiple regions of the frontal, temporal, parietal, and occipital cortices. Significant regional cerebral blood flow increases were observed in some regions of the medial temporal lobe, including the amygdala, the hippocampal gyrus, and the cerebellum. The pattern of subjective effects induced by salvinorin-A was similar to those observed in relation to other psychotomimetic drugs but with an evidently dissociative nature. No dysphoric effects were reported. CONCLUSION The salvinorin-A-mediated KOR agonism induced dramatic psychotomimetic effects along with a generalized decrease in cerebral blood flow and electric activity within the cerebral cortex.
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Affiliation(s)
- Genís Ona
- Human Neuropsychopharmacology Group, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain
| | - Frederic Sampedro
- Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain,Centro de Investigación en Red-Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain,Correspondence: Frederic Sampedro, PhD, Hospital de Sant Pau Research Institute, Sant Quintí Street number 77, 08041 Barcelona, Spain ()
| | - Sergio Romero
- Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - Marta Valle
- Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Valle Camacho
- Nuclear Medicine Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Carolina Migliorelli
- Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - Miguel Ángel Mañanas
- Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - Rosa Maria Antonijoan
- Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona, Barcelona, Spain,Centre d’Investigació de Medicaments, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain,Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain
| | - Montserrat Puntes
- Centre d’Investigació de Medicaments, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain
| | - Jimena Coimbra
- Centre d’Investigació de Medicaments, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain
| | - Maria Rosa Ballester
- Centre d’Investigació de Medicaments, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain,Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain,Blanquerna School of Health Science, Universitat Ramon Llull, Barcelona, Spain
| | - Maite Garrido
- Centre d’Investigació de Medicaments, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Barcelona, Spain
| | - Jordi Riba
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht,the Netherlands
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18
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Madsen MK, Stenbæk DS, Arvidsson A, Armand S, Marstrand-Joergensen MR, Johansen SS, Linnet K, Ozenne B, Knudsen GM, Fisher PM. Psilocybin-induced changes in brain network integrity and segregation correlate with plasma psilocin level and psychedelic experience. Eur Neuropsychopharmacol 2021; 50:121-132. [PMID: 34246868 DOI: 10.1016/j.euroneuro.2021.06.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 11/28/2022]
Abstract
The emerging novel therapeutic psilocybin produces psychedelic effects via engagement of cerebral serotonergic targets by psilocin (active metabolite). The serotonin 2A receptor critically mediates these effects by altering distributed neural processes that manifest as increased entropy, reduced functional connectivity (FC) within discrete brain networks (i.e., reduced integrity) and increased FC between networks (i.e., reduced segregation). Reduced integrity of the default mode network (DMN) is proposed to play a particularly prominent role in psychedelic phenomenology, including perceived ego-dissolution. Here, we investigate the effects of a psychoactive peroral dose of psilocybin (0.2-0.3 mg/kg) on plasma psilocin level (PPL), subjective drug intensity (SDI) and their association in fifteen healthy individuals. We further evaluate associations between these measures and resting-state FC, measured with functional magnetic resonance imaging, acquired over the course of five hours after psilocybin administration. We show that PPL and SDI correlate negatively with measures of network integrity (including DMN) and segregation, both spatially constrained and unconstrained. We also find that the executive control network and dorsal attention network desegregate, increasing connectivity with other networks and throughout the brain as a function of PPL and SDI. These findings provide direct evidence that psilocin critically shapes the time course and magnitude of changes in the cerebral functional architecture and subjective experience following psilocybin administration. Our findings provide novel insight into the neurobiological mechanisms underlying profound perceptual experiences evoked by this emerging transnosological therapeutic and implicate the expression of network integrity and segregation in the psychedelic experience and consciousness.
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Affiliation(s)
- Martin K Madsen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Dea S Stenbæk
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Albin Arvidsson
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Sophia Armand
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Maja R Marstrand-Joergensen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Sys S Johansen
- Section of Forensic Chemistry, Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Kristian Linnet
- Section of Forensic Chemistry, Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Brice Ozenne
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark; Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Patrick M Fisher
- Neurobiology Research Unit and NeuroPharm, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark.
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19
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Yaden DB, Johnson MW, Griffiths RR, Doss MK, Garcia-Romeu A, Nayak S, Gukasyan N, Mathur BN, Barrett FS. Psychedelics and Consciousness: Distinctions, Demarcations, and Opportunities. Int J Neuropsychopharmacol 2021; 24:615-623. [PMID: 33987652 PMCID: PMC8378075 DOI: 10.1093/ijnp/pyab026] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/06/2021] [Accepted: 05/10/2021] [Indexed: 12/13/2022] Open
Abstract
Psychedelic substances produce unusual and compelling changes in conscious experience that have prompted some to propose that psychedelics may provide unique insights explaining the nature of consciousness. At present, psychedelics, like other current scientific tools and methods, seem unlikely to provide information relevant to the so-called "hard problem of consciousness," which involves explaining how first-person experience can emerge. However, psychedelics bear on multiple "easy problems of consciousness," which involve relations between subjectivity, brain function, and behavior. In this review, we discuss common meanings of the term "consciousness" when used with regard to psychedelics and consider some models of the effects of psychedelics on the brain that have also been associated with explanatory claims about consciousness. We conclude by calling for epistemic humility regarding the potential for psychedelic research to aid in explaining the hard problem of consciousness while pointing to ways in which psychedelics may advance the study of many specific aspects of consciousness.
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Affiliation(s)
- David B Yaden
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
| | - Matthew W Johnson
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
| | - Roland R Griffiths
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
- Department of Neuroscience
| | - Manoj K Doss
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
| | - Albert Garcia-Romeu
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
| | - Sandeep Nayak
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
| | - Natalie Gukasyan
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
| | - Brian N Mathur
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Frederick S Barrett
- Department of Psychiatry and Behavioral Sciences
- Center for Psychedelic and Consciousness Research
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20
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Mertens LJ, Preller KH. Classical Psychedelics as Therapeutics in Psychiatry - Current Clinical Evidence and Potential Therapeutic Mechanisms in Substance Use and Mood Disorders. PHARMACOPSYCHIATRY 2021; 54:176-190. [PMID: 33472250 DOI: 10.1055/a-1341-1907] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Classical psychedelics, primarily psilocybin and lysergic acid diethylamide (LSD), have been used and extensively studied in Western medicine as part of substance-assisted psychotherapy in the 1950s and 1960s. Modern clinical research is currently gaining momentum and provides new evidence for the safety and efficacy of classical psychedelics (primarily psilocybin, but also LSD and ayahuasca) in the treatment of different psychiatric conditions, including substance use and mood disorders.In this review article, we outline common pathological mechanisms of substance use disorders (SUD) and unipolar depression. Next, the current literature on the effects of psychedelics is summarized in order to generate hypotheses regarding their potential therapeutic mechanisms of action in treating these psychiatric conditions. Finally, we review and discuss clinical trials published since 2011 investigating the effects of psychedelics in SUD and depression.While results from those modern clinical trials are promising, most of them do not meet the methodological requirements to allow firm conclusions on the clinical efficacy of psychedelics. Larger, blinded, randomized controlled trials (RCT) with clearly defined patient groups and well-defined primary endpoints are needed. Additionally, the therapeutic mechanisms of classical psychedelics are currently unknown. This review presents hypotheses derived from preclinical and human studies that need to be tested in future trials to better understand the clinical potential of psychedelic substances in modern psychiatry.
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Affiliation(s)
- Lea J Mertens
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Katrin H Preller
- Pharmaco-Neuroimaging and Cognitive-Emotional Processing, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry Zurich, Zurich, Switzerland.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA
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21
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Johnson MW. Consciousness, Religion, and Gurus: Pitfalls of Psychedelic Medicine. ACS Pharmacol Transl Sci 2020; 4:578-581. [PMID: 33860187 DOI: 10.1021/acsptsci.0c00198] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Indexed: 12/26/2022]
Abstract
This viewpoint identifies pitfalls in the study of psychedelic compounds, including those that pose challenges for the potential use of psychedelics as medicines. They are as follows: (1) Sloppiness regarding use of the term "consciousness". (2) Inappropriate introduction of religious/spiritual beliefs of investigators or clinicians. (3) Clinical boundaries and other ethical challenges associated with psychedelic treatments.
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Affiliation(s)
- Matthew W Johnson
- Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland 21224, United States
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