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Higa GSV, Viana FJC, Francis-Oliveira J, Cruvinel E, Franchin TS, Marcourakis T, Ulrich H, De Pasquale R. Serotonergic neuromodulation of synaptic plasticity. Neuropharmacology 2024; 257:110036. [PMID: 38876308 DOI: 10.1016/j.neuropharm.2024.110036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Synaptic plasticity constitutes a fundamental process in the reorganization of neural networks that underlie memory, cognition, emotional responses, and behavioral planning. At the core of this phenomenon lie Hebbian mechanisms, wherein frequent synaptic stimulation induces long-term potentiation (LTP), while less activation leads to long-term depression (LTD). The synaptic reorganization of neuronal networks is regulated by serotonin (5-HT), a neuromodulator capable of modify synaptic plasticity to appropriately respond to mental and behavioral states, such as alertness, attention, concentration, motivation, and mood. Lately, understanding the serotonergic Neuromodulation of synaptic plasticity has become imperative for unraveling its impact on cognitive, emotional, and behavioral functions. Through a comparative analysis across three main forebrain structures-the hippocampus, amygdala, and prefrontal cortex, this review discusses the actions of 5-HT on synaptic plasticity, offering insights into its role as a neuromodulator involved in emotional and cognitive functions. By distinguishing between plastic and metaplastic effects, we provide a comprehensive overview about the mechanisms of 5-HT neuromodulation of synaptic plasticity and associated functions across different brain regions.
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Affiliation(s)
- Guilherme Shigueto Vilar Higa
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil; Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Felipe José Costa Viana
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - José Francis-Oliveira
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Emily Cruvinel
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Thainá Soares Franchin
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Tania Marcourakis
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Henning Ulrich
- Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Roberto De Pasquale
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil.
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Olson RJ, Bartlett L, Sonneborn A, Milton R, Bretton-Granatoor Z, Firdous A, Harris AZ, Abbas AI. Decoupling of cortical activity from behavioral state following administration of the classic psychedelic DOI. Neuropharmacology 2024; 257:110030. [PMID: 38851531 PMCID: PMC11260522 DOI: 10.1016/j.neuropharm.2024.110030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/02/2024] [Accepted: 06/04/2024] [Indexed: 06/10/2024]
Abstract
Administration or consumption of classic psychedelics (CPs) leads to profound changes in experience which are often described as highly novel and meaningful. They have shown substantial promise in treating depressive symptoms and may be therapeutic in other situations. Although research suggests that the therapeutic response is correlated with the intensity of the experience, the neural circuit basis for the alterations in experience caused by CPs requires further study. The medial prefrontal cortex (mPFC), where CPs have been shown to induce rapid, 5-HT2A receptor-dependent structural and neurophysiological changes, is believed to be a key site of action. To investigate the acute neural circuit changes induced by CPs, we recorded single neurons and local field potentials in the mPFC of freely behaving male mice after administration of the 5-HT2A/2C receptor-selective CP, 2,5-Dimethoxy-4-iodoamphetamine (DOI). We segregated recordings into active and rest periods in order to examine cortical activity during desynchronized (active) and synchronized (rest) states. We found that DOI induced a robust decrease in low frequency power when animals were at rest, attenuating the usual synchronization that occurs during less active behavioral states. DOI also increased broadband gamma power and suppressed activity in fast-spiking neurons in both active and rest periods. Together, these results suggest that the CP DOI induces persistent desynchronization in mPFC, including during rest when mPFC typically exhibits more synchronized activity. This shift in cortical dynamics may in part underlie the longer-lasting effects of CPs on plasticity, and may be critical to their therapeutic properties.
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Affiliation(s)
- Randall J Olson
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | - Lowell Bartlett
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | - Alex Sonneborn
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | - Russell Milton
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA
| | | | - Ayesha Firdous
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10034, USA
| | - Alexander Z Harris
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10034, USA; Department of Psychiatry, Columbia University, New York, NY, 10034, USA
| | - Atheir I Abbas
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland OR 97239, USA; Department of Psychiatry, Oregon Health and Science University, Portland OR 97239, USA; VA Portland Health Care System, Portland OR, 97239, USA.
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Caspani G, Ruffell SGD, Tsang W, Netzband N, Rohani-Shukla C, Swann JR, Jefferies WA. Mind over matter: the microbial mindscapes of psychedelics and the gut-brain axis. Pharmacol Res 2024; 207:107338. [PMID: 39111558 DOI: 10.1016/j.phrs.2024.107338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 07/31/2024] [Accepted: 07/31/2024] [Indexed: 08/12/2024]
Abstract
Psychedelics have emerged as promising therapeutics for several psychiatric disorders. Hypotheses around their mechanisms have revolved around their partial agonism at the serotonin 2 A receptor, leading to enhanced neuroplasticity and brain connectivity changes that underlie positive mindset shifts. However, these accounts fail to recognise that the gut microbiota, acting via the gut-brain axis, may also have a role in mediating the positive effects of psychedelics on behaviour. In this review, we present existing evidence that the composition of the gut microbiota may be responsive to psychedelic drugs, and in turn, that the effect of psychedelics could be modulated by microbial metabolism. We discuss various alternative mechanistic models and emphasize the importance of incorporating hypotheses that address the contributions of the microbiome in future research. Awareness of the microbial contribution to psychedelic action has the potential to significantly shape clinical practice, for example, by allowing personalised psychedelic therapies based on the heterogeneity of the gut microbiota.
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Affiliation(s)
- Giorgia Caspani
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, East Mall, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; Department of Urologic Sciences, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, Level 6, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada.
| | - Simon G D Ruffell
- Psychae Institute, Melbourne, Australia; School of Population and Global Health, University of Melbourne, 207 Bouverie St, Carlton, VIC 3053, Australia
| | - WaiFung Tsang
- Institute of Psychiatry, Psychology & Neuroscience, King'sCollege London, Department of Psychology, De Crespigny Park, London SE5 8AF, UK
| | - Nigel Netzband
- University of West of England, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY, UK
| | - Cyrus Rohani-Shukla
- Centre for Psychedelic Research, Imperial College London, Hammersmith Hospital, Du Cane Rd, London W12 0HS, UK
| | - Jonathan R Swann
- School of Human Development and Health, Faculty of Medicine, University of Southampton, 12 University Rd, Southampton SO17 1BJ, UK; Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Wilfred A Jefferies
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, East Mall, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; Department of Urologic Sciences, University of British Columbia, Gordon & Leslie Diamond Health Care Centre, Level 6, 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada.
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Sarasso P, Billeci M, Ronga I, Raffone F, Martiadis V, Di Petta G. Disembodiment and Affective Resonances in Esketamine Treatment of Depersonalized Depression Subtype: Two Case Studies. Psychopathology 2024:1-12. [PMID: 39173608 DOI: 10.1159/000539714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 06/02/2024] [Indexed: 08/24/2024]
Abstract
INTRODUCTION Dissociative experiences are considered undesirable ketamine's adverse events. However, they might be crucial for ketamine's antidepressant effects, at least in some depression subtypes. Current understandings of ketamine's therapeutic potentials converge on the so-called "relaxed prior hypothesis," suggesting that glutamatergic blockage up-weights bottom-up surprising somatosensory/affective states. As a result, ketamine improves short-term plasticity in depression by enhancing sensitivity to interoceptive signals. METHODS We selected 2 case studies for their paradigmatic description of "depersonalized depression" (Entfremdungsdepression) symptoms. Patients were included in a 6-month-long esketamine program for treatment resistant depression, during which we collected their spontaneous experience with esketamine. According to a neurophenomenological approach, we combined subjective reports from unstructured clinical interviews and the review of previous objective neuroimaging results and neurocomputational models to unveil the relation between esketamine antidepressant effects and interoceptive sensitivity. RESULTS According to our clinical observations, esketamine-induced dissociation might be particularly effective in the depersonalized depression subtype, in which interoceptive awareness and interaffectivity are particularly compromised. Ketamine and esketamine's dissociative effects and particularly disembodiment might suspend previously acquired patterns of feeling, sensing, and behaving. CONCLUSIONS Coherently with previous research, we suggest that esketamine-induced disembodiment allows for a transient window of psychological plasticity and enhanced sensitivity, where the body recovers its permeability to affective affordances.
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Affiliation(s)
- Pietro Sarasso
- Brain Plasticity and Behaviour Changes Research Group, Department of Psychology, University of Turin, Turin, Italy
| | - Martina Billeci
- SPDC, Mental Health Department, Santa Maria delle Grazie Hospital, ASL 2, Naples, Italy
| | - Irene Ronga
- Brain Plasticity and Behaviour Changes Research Group, Department of Psychology, University of Turin, Turin, Italy
| | | | | | - Gilberto Di Petta
- SPDC, Mental Health Department, Santa Maria delle Grazie Hospital, ASL 2, Naples, Italy
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Mograbi DC, Rodrigues R, Bienemann B, Huntley J. Brain Networks, Neurotransmitters and Psychedelics: Towards a Neurochemistry of Self-Awareness. Curr Neurol Neurosci Rep 2024; 24:323-340. [PMID: 38980658 PMCID: PMC11258181 DOI: 10.1007/s11910-024-01353-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2024] [Indexed: 07/10/2024]
Abstract
PURPOSE OF REVIEW Self-awareness can be defined as the capacity of becoming the object of one's own awareness and, increasingly, it has been the target of scientific inquiry. Self-awareness has important clinical implications, and a better understanding of the neurochemical basis of self-awareness may help clarifying causes and developing interventions for different psychopathological conditions. The current article explores the relationship between neurochemistry and self-awareness, with special attention to the effects of psychedelics. RECENT FINDINGS The functioning of self-related networks, such as the default-mode network and the salience network, and how these are influenced by different neurotransmitters is discussed. The impact of psychedelics on self-awareness is reviewed in relation to specific processes, such as interoception, body ownership, agency, metacognition, emotional regulation and autobiographical memory, within a framework based on predictive coding. Improved outcomes in emotional regulation and autobiographical memory have been observed in association with the use of psychedelics, suggesting higher-order self-awareness changes, which can be modulated by relaxation of priors and improved coping mechanisms linked to cognitive flexibility. Alterations in bodily self-awareness are less consistent, being potentially impacted by doses employed, differences in acute/long-term effects and the presence of clinical conditions. Future studies investigating the effects of different molecules in rebalancing connectivity between resting-state networks may lead to novel therapeutic approaches and the refinement of existing treatments.
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Affiliation(s)
- Daniel C Mograbi
- Department of Psychology, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil.
- Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.
| | - Rafael Rodrigues
- Department of Psychology, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bheatrix Bienemann
- Department of Psychology, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jonathan Huntley
- Division of Psychiatry, University College London, London, UK
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
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Owe-Larsson M, Kamińska K, Buchalska B, Mirowska-Guzel D, Cudnoch-Jędrzejewska A. Psilocybin in pharmacotherapy of obsessive-compulsive disorder. Pharmacol Rep 2024:10.1007/s43440-024-00633-1. [PMID: 39088105 DOI: 10.1007/s43440-024-00633-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 07/09/2024] [Accepted: 07/23/2024] [Indexed: 08/02/2024]
Abstract
Obsessive-compulsive disorder (OCD) is a chronic mental disease that affects approximately 2% of the population. Obsessions and compulsions are troublesome for patients and may disturb their everyday activities. The pathogenesis of this disease is still not fully elucidated, but dysfunctions of serotonin-, dopamine- and glutamate-mediated neurotransmission together with early maladaptive schemas seem of importance. Pharmacological treatment includes drugs affecting the serotoninergic, dopaminergic, and glutamatergic systems, such as selective serotonin reuptake inhibitors (SSRIs). Providing that up to 40% of patients with OCD are resistant to the currently available medications, there is a need for novel and effective therapies. Recent discoveries suggest that psilocybin, a non-physically addictive psychoactive substance, may ameliorate disease symptoms. When used in appropriate doses and under strict clinical control, psilocybin appears as a valuable treatment for OCD. This narrative article provides a thorough overview of OCD's etiology, current treatment options, and the emerging evidence supporting psilocybin's efficacy in managing OCD symptoms.
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Affiliation(s)
- Maja Owe-Larsson
- Laboratory of Center for Preclinical Research, Department of Experimental and Clinical Physiology, Medical University of Warsaw, Banacha 1B, Warszawa, 02-097, Poland.
| | - Katarzyna Kamińska
- Laboratory of Center for Preclinical Research, Department of Experimental and Clinical Physiology, Medical University of Warsaw, Banacha 1B, Warszawa, 02-097, Poland.
| | - Barbara Buchalska
- Laboratory of Center for Preclinical Research, Department of Experimental and Clinical Physiology, Medical University of Warsaw, Banacha 1B, Warszawa, 02-097, Poland
| | - Dagmara Mirowska-Guzel
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Warszawa, Poland
| | - Agnieszka Cudnoch-Jędrzejewska
- Laboratory of Center for Preclinical Research, Department of Experimental and Clinical Physiology, Medical University of Warsaw, Banacha 1B, Warszawa, 02-097, Poland
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Tipado Z, Kuypers KPC, Sorger B, Ramaekers JG. Visual hallucinations originating in the retinofugal pathway under clinical and psychedelic conditions. Eur Neuropsychopharmacol 2024; 85:10-20. [PMID: 38648694 DOI: 10.1016/j.euroneuro.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 04/11/2024] [Accepted: 04/13/2024] [Indexed: 04/25/2024]
Abstract
Psychedelics like LSD (Lysergic acid diethylamide) and psilocybin are known to modulate perceptual modalities due to the activation of mostly serotonin receptors in specific cortical (e.g., visual cortex) and subcortical (e.g., thalamus) regions of the brain. In the visual domain, these psychedelic modulations often result in peculiar disturbances of viewed objects and light and sometimes even in hallucinations of non-existent environments, objects, and creatures. Although the underlying processes are poorly understood, research conducted over the past twenty years on the subjective experience of psychedelics details theories that attempt to explain these perceptual alterations due to a disruption of communication between cortical and subcortical regions. However, rare medical conditions in the visual system like Charles Bonnet syndrome that cause perceptual distortions may shed new light on the additional importance of the retinofugal pathway in psychedelic subjective experiences. Interneurons in the retina called amacrine cells could be the first site of visual psychedelic modulation and aid in disrupting the hierarchical structure of how humans perceive visual information. This paper presents an understanding of how the retinofugal pathway communicates and modulates visual information in psychedelic and clinical conditions. Therefore, we elucidate a new theory of psychedelic modulation in the retinofugal pathway.
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Affiliation(s)
- Zeus Tipado
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands; Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands.
| | - Kim P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Bettina Sorger
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
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Kuhn RL. A landscape of consciousness: Toward a taxonomy of explanations and implications. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2024; 190:28-169. [PMID: 38281544 DOI: 10.1016/j.pbiomolbio.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 09/12/2023] [Accepted: 12/25/2023] [Indexed: 01/30/2024]
Abstract
Diverse explanations or theories of consciousness are arrayed on a roughly physicalist-to-nonphysicalist landscape of essences and mechanisms. Categories: Materialism Theories (philosophical, neurobiological, electromagnetic field, computational and informational, homeostatic and affective, embodied and enactive, relational, representational, language, phylogenetic evolution); Non-Reductive Physicalism; Quantum Theories; Integrated Information Theory; Panpsychisms; Monisms; Dualisms; Idealisms; Anomalous and Altered States Theories; Challenge Theories. There are many subcategories, especially for Materialism Theories. Each explanation is self-described by its adherents, critique is minimal and only for clarification, and there is no attempt to adjudicate among theories. The implications of consciousness explanations or theories are assessed with respect to four questions: meaning/purpose/value (if any); AI consciousness; virtual immortality; and survival beyond death. A Landscape of Consciousness, I suggest, offers perspective.
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Hervig MES, Zühlsdorff K, Olesen SF, Phillips B, Božič T, Dalley JW, Cardinal RN, Alsiö J, Robbins TW. 5-HT 2A and 5-HT 2C receptor antagonism differentially modulate reinforcement learning and cognitive flexibility: behavioural and computational evidence. Psychopharmacology (Berl) 2024; 241:1631-1644. [PMID: 38594515 PMCID: PMC11269483 DOI: 10.1007/s00213-024-06586-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 03/29/2024] [Indexed: 04/11/2024]
Abstract
RATIONALE Cognitive flexibility, the ability to adapt behaviour in response to a changing environment, is disrupted in several neuropsychiatric disorders, including obsessive-compulsive disorder and major depressive disorder. Evidence suggests that flexibility, which can be operationalised using reversal learning tasks, is modulated by serotonergic transmission. However, how exactly flexible behaviour and associated reinforcement learning (RL) processes are modulated by 5-HT action on specific receptors is unknown. OBJECTIVES We investigated the effects of 5-HT2A receptor (5-HT2AR) and 5-HT2C receptor (5-HT2CR) antagonism on flexibility and underlying RL mechanisms. METHODS Thirty-six male Lister hooded rats were trained on a touchscreen visual discrimination and reversal task. We evaluated the effects of systemic treatments with the 5-HT2AR and 5-HT2CR antagonists M100907 and SB-242084, respectively, on reversal learning and performance on probe trials where correct and incorrect stimuli were presented with a third, probabilistically rewarded, stimulus. Computational models were fitted to task choice data to extract RL parameters, including a novel model designed specifically for this task. RESULTS 5-HT2AR antagonism impaired reversal learning only after an initial perseverative phase, during a period of random choice and then new learning. 5-HT2CR antagonism, on the other hand, impaired learning from positive feedback. RL models further differentiated these effects. 5-HT2AR antagonism decreased punishment learning rate (i.e. negative feedback) at high and low doses. The low dose also decreased reinforcement sensitivity (beta) and increased stimulus and side stickiness (i.e., the tendency to repeat a choice regardless of outcome). 5-HT2CR antagonism also decreased beta, but reduced side stickiness. CONCLUSIONS These data indicate that 5-HT2A and 5-HT2CRs both modulate different aspects of flexibility, with 5-HT2ARs modulating learning from negative feedback as measured using RL parameters and 5-HT2CRs for learning from positive feedback assessed through conventional measures.
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Affiliation(s)
- Mona El-Sayed Hervig
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Neuroscience, University of Copenhagen, Copenhagen, DK-2200, Denmark
| | - Katharina Zühlsdorff
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK.
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK.
- The Alan Turing Institute, British Library, London, NW1 2DVB, UK.
| | - Sarah F Olesen
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, W1T 4JG, UK
| | - Benjamin Phillips
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
| | - Tadej Božič
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, W1T 4JG, UK
| | - Jeffrey W Dalley
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, Herchel Smith Building, Cambridge, CB2 0SZ, UK
| | - Rudolf N Cardinal
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, Herchel Smith Building, Cambridge, CB2 0SZ, UK
- Liaison Psychiatry Service, Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge Biomedical Campus, Box 190, Cambridge, CB2 0QQ, UK
| | - Johan Alsiö
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Trevor W Robbins
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
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Aday JS, Horton D, Fernandes-Osterhold G, O'Donovan A, Bradley ER, Rosen RC, Woolley JD. Psychedelic-assisted psychotherapy: where is the psychotherapy research? Psychopharmacology (Berl) 2024; 241:1517-1526. [PMID: 38782821 DOI: 10.1007/s00213-024-06620-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
RATIONALE Psychedelic-assisted psychotherapy (PAP) has emerged as a potential treatment for a variety of mental health conditions, including substance use disorders and depression. Current models of PAP emphasize the importance of psychotherapeutic support before, during, and after ingestion of a psychedelic to maximize safety and clinical benefit. Despite this ubiquitous assumption, there has been surprisingly little empirical investigation of the "psychotherapy" in PAP, leaving critical questions about the necessary and sufficient components of PAP unanswered. OBJECTIVES As clinical trials for psychedelic compounds continue the transition from safety- and feasibility-testing to evaluating efficacy, the role of the accompanying psychotherapy must be better understood to enhance scientific understanding of the mechanisms underlying therapeutic change, optimize clinical outcomes, and inform cost-effectiveness. RESULTS The present paper first reviews the current status of psychotherapy in the PAP literature, starting with recent debates regarding "psychotherapy" versus "psychological support" and then overviewing published clinical trial psychotherapy models and putative models informed by theory. We then delineate lessons that PAP researchers can leverage from traditional psychotherapy research regarding standardizing treatments (e.g., publish treatment manuals, establish eligibility criteria for providers), identifying mechanisms of change (e.g., measure established mechanisms in psychotherapy), and optimizing clinical trial designs (e.g., consider dismantling studies, comparative efficacy trials, and cross-lagged panel designs). Throughout this review, the need for increased research into the psychotherapeutic components of treatment in PAP is underscored. CONCLUSIONS PAP is a distinct, integrative, and transdisciplinary intervention. Future research designs should consider transdisciplinary research methodologies to identify best practices and inform federal guidelines for PAP administration.
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Affiliation(s)
- Jacob S Aday
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA.
| | - David Horton
- Department of Family Medicine and Community Health, University of Wisconsin, Madison, Madison, WI, USA
| | | | - Aoife O'Donovan
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA
| | - Ellen R Bradley
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA
- San Francisco VA Medical Center, San Francisco, CA, USA
| | - Raymond C Rosen
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA
| | - Joshua D Woolley
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA
- San Francisco VA Medical Center, San Francisco, CA, USA
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Herzog R, Barbey FM, Islam MN, Rueda-Delgado L, Nolan H, Prado P, Krylova M, Izyurov I, Javaheripour N, Danyeli LV, Sen ZD, Walter M, O'Donnell P, Buhl DL, Murphy B, Ibanez A. High-order brain interactions in ketamine during rest and task: a double-blinded cross-over design using portable EEG on male participants. Transl Psychiatry 2024; 14:310. [PMID: 39068157 PMCID: PMC11283531 DOI: 10.1038/s41398-024-03029-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 07/12/2024] [Accepted: 07/17/2024] [Indexed: 07/30/2024] Open
Abstract
Ketamine is a dissociative anesthetic that induces a shift in global consciousness states and related brain dynamics. Portable low-density EEG systems could be used to monitor these effects. However, previous evidence is almost null and lacks adequate methods to address global dynamics with a small number of electrodes. This study delves into brain high-order interactions (HOI) to explore the effects of ketamine using portable EEG. In a double-blinded cross-over design, 30 male adults (mean age = 25.57, SD = 3.74) were administered racemic ketamine and compared against saline infusion as a control. Both task-driven (auditory oddball paradigm) and resting-state EEG were recorded. HOI were computed using advanced multivariate information theory tools, allowing us to quantify nonlinear statistical dependencies between all possible electrode combinations. Ketamine induced an increase in redundancy in brain dynamics (copies of the same information that can be retrieved from 3 or more electrodes), most significantly in the alpha frequency band. Redundancy was more evident during resting state, associated with a shift in conscious states towards more dissociative tendencies. Furthermore, in the task-driven context (auditory oddball), the impact of ketamine on redundancy was more significant for predictable (standard stimuli) compared to deviant ones. Finally, associations were observed between ketamine's HOI and experiences of derealization. Ketamine appears to increase redundancy and HOI across psychometric measures, suggesting these effects are correlated with alterations in consciousness towards dissociation. In comparisons with event-related potential (ERP) or standard functional connectivity metrics, HOI represent an innovative method to combine all signal spatial interactions obtained from low-density dry EEG in drug interventions, as it is the only approach that exploits all possible combinations between electrodes. This research emphasizes the potential of complexity measures coupled with portable EEG devices in monitoring shifts in consciousness, especially when paired with low-density configurations, paving the way for better understanding and monitoring of pharmacological-induced changes.
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Affiliation(s)
- Rubén Herzog
- Latin American Brain Health Institute, Universidad Adolfo Ibañez, Santiago de Chile, Chile.
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France.
| | | | | | | | - Hugh Nolan
- Cumulus Neuroscience Ltd, Dublin, Ireland
| | - Pavel Prado
- Escuela de Fonoaudiología, Facultad de Odontología y Ciencias de la Rehabilitación, Universidad San Sebastián, Santiago, Chile
| | - Marina Krylova
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Igor Izyurov
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Nooshin Javaheripour
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Lena Vera Danyeli
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Zümrüt Duygu Sen
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Martin Walter
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
- German Center for Mental Health (DZPG), partner site Halle-Jena-Magdeburg, Jena, Germany
| | - Patricio O'Donnell
- Neuroscience Drug Discovery Unit, Takeda Pharmaceuticals, Cambridge, MA, 02390, USA
| | - Derek L Buhl
- Neuroscience Drug Discovery Unit, Takeda Pharmaceuticals, Cambridge, MA, 02390, USA
| | | | - Agustin Ibanez
- Latin American Brain Health Institute, Universidad Adolfo Ibañez, Santiago de Chile, Chile.
- Global Brain Health Institute, UCSF and Trinity College Dublin, Dublin, Ireland.
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12
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Hutten NRPW, Quaedflieg CWEM, Mason NL, Theunissen EL, Liechti ME, Duthaler U, Kuypers KPC, Bonnelle V, Feilding A, Ramaekers JG. Inter-individual variability in neural response to low doses of LSD. Transl Psychiatry 2024; 14:288. [PMID: 39009578 PMCID: PMC11251148 DOI: 10.1038/s41398-024-03013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 06/21/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024] Open
Abstract
The repeated use of small doses of psychedelics (also referred to as "microdosing") to facilitate benefits in mental health, cognition, and mood is a trending practice. Placebo-controlled studies however have largely failed to demonstrate strong benefits, possibly because of large inter-individual response variability. The current study tested the hypothesis that effects of low doses of LSD on arousal, attention and memory depend on an individual's cognitive state at baseline. Healthy participants (N = 53) were randomly assigned to receive repeated doses of LSD (15 mcg) or placebo on 4 occasions divided over 2 weeks. Each treatment condition also consisted of a baseline and a 1-week follow-up visit. Neurophysiological measures of arousal (resting state EEG), pre-attentive processing (auditory oddball task), and perceptual learning and memory (visual long-term potentiation (LTP) paradigm) were assessed at baseline, dosing session 1 and 4, and follow-up. LSD produced stimulatory effects as reflected by a reduction in resting state EEG delta, theta, and alpha power, and enhanced pre-attentive processing during the acute dosing sessions. LSD also blunted the induction of LTP on dosing session 4. Stimulatory effects of LSD were strongest in individuals with low arousal and attention at baseline, while inhibitory effects were strongest in high memory performers at baseline. Decrements in delta EEG power and enhanced pre-attentive processing in the LSD treatment condition were still present during the 1-week follow-up. The current study demonstrates across three cognitive domains, that acute responses to low doses of LSD depend on the baseline state and provides some support for LSD induced neuroadaptations that sustain beyond treatment.
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Affiliation(s)
- Nadia R P W Hutten
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Conny W E M Quaedflieg
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Natasha L Mason
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Eef L Theunissen
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Matthias E Liechti
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Urs Duthaler
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Kim P C Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | | | | | - Johannes G Ramaekers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands.
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13
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Martin DA, Delgado AM, Calu DJ. Effects of psychedelic, DOI, on nucleus accumbens dopamine signaling to predictable rewards and cues in rats. Neuropsychopharmacology 2024:10.1038/s41386-024-01912-4. [PMID: 38971932 DOI: 10.1038/s41386-024-01912-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 06/10/2024] [Accepted: 06/24/2024] [Indexed: 07/08/2024]
Abstract
Psychedelics produce lasting therapeutic responses in neuropsychiatric diseases suggesting they may disrupt entrenched associations and catalyze learning. Here, we examine psychedelic 5-HT2A/2C agonist, DOI, effects on dopamine signaling in the nucleus accumbens (NAc) core, a region extensively linked to reward learning, motivation, and drug-seeking. We measure phasic dopamine transients following acute DOI administration in rats during well learned Pavlovian tasks in which sequential cues predict rewards. We find that DOI (0.0-1.2 mg/kg, i.p.) increases dopamine signals, photometrically measured using GRABDA optical sensor, to rewards and proximal reward cues, but not to the distal cues that predict these events. We determine that the elevated dopamine produced by DOI to reward cues occurs independently of DOI-induced changes in reward value. The increased dopamine associated with predictable reward cues and rewards supports DOI-induced increases in prediction error signaling. These findings lay a foundation for developing psychedelic strategies aimed at engaging error-driven learning mechanisms to disrupt entrenched associations or produce new associations.
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Affiliation(s)
- David A Martin
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Angel M Delgado
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Donna J Calu
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
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14
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Romeo B, Kervadec E, Fauvel B, Strika-Bruneau L, Amirouche A, Verroust V, Piolino P, Benyamina A. Significant Psychedelic Experiences Evaluated for Mystical Characteristics Associated with Cannabis Use Reduction and Psychological Flexibility Improvement: A Naturalistic Cross-Sectional Retrospective Survey. J Psychoactive Drugs 2024:1-12. [PMID: 38961652 DOI: 10.1080/02791072.2024.2375720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 05/13/2024] [Indexed: 07/05/2024]
Abstract
Treating cannabis use disorder remains a significant challenge in the field of addiction medicine. Some recent studies point to psychedelic-assisted psychotherapy as a potential treatment option for substance use disorders. The objective of this study was therefore to explore the impact of naturalistic psychedelic experiences on cannabis use and psychological flexibility. An online retrospective survey was carried out on 152 cannabis users who also reported a significant experience induced by psychedelics in the past. Following a psychedelic experience, there was a significant and sustained reduction of average CUDIT score (p < .001), frequency of cannabis use (p < .001), and acute duration of daily intoxication (p < .001). Cannabis use reduction during the first month post-experience was significantly associated with the intensity of the mystical experience (p = .01). Participants reported a concomitant increased lasting improvement of psychological flexibility following the experience (p < .001), which was correlated to the intensity of the mystical experience during the first month post-experience (p = .04). This study demonstrates that naturalistic psychedelic experiences may be followed by a decrease in cannabis use. Positive health outcomes appear potentially connected to the intensity of the mystical experience, as well as an improvement in psychological flexibility.
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Affiliation(s)
- B Romeo
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions, PSYCOMADD - Paris Saclay University Île-de-France, Villejuif, France
| | - E Kervadec
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif, France
| | - B Fauvel
- Laboratoire Mémoire, Cerveau et Cognition (UR 7536), Institut de Psychologie, Université Paris Cité, Paris, France
| | - L Strika-Bruneau
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions, PSYCOMADD - Paris Saclay University Île-de-France, Villejuif, France
| | - A Amirouche
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions, PSYCOMADD - Paris Saclay University Île-de-France, Villejuif, France
| | - V Verroust
- Unité de Recherche Psychiatrie-Comorbidités-Addictions, PSYCOMADD - Paris Saclay University Île-de-France, Villejuif, France
- Université Picardie-Jules Vernes, Amiens, France
| | - P Piolino
- Laboratoire Mémoire, Cerveau et Cognition (UR 7536), Institut de Psychologie, Université Paris Cité, Paris, France
| | - A Benyamina
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions, PSYCOMADD - Paris Saclay University Île-de-France, Villejuif, France
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15
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Stoliker D, Novelli L, Vollenweider FX, Egan GF, Preller KH, Razi A. Neural Mechanisms of Resting-State Networks and the Amygdala Underlying the Cognitive and Emotional Effects of Psilocybin. Biol Psychiatry 2024; 96:57-66. [PMID: 38185235 DOI: 10.1016/j.biopsych.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 12/19/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
BACKGROUND Serotonergic psychedelics, such as psilocybin, alter perceptual and cognitive systems that are functionally integrated with the amygdala. These changes can alter cognition and emotions that are hypothesized to contribute to their therapeutic utility. However, the neural mechanisms of cognitive and subcortical systems altered by psychedelics are not well understood. METHODS We used resting-state functional magnetic resonance images collected during a randomized, double-blind, placebo-controlled clinical trial of 24 healthy adults under 0.2 mg/kg psilocybin to estimate the directed (i.e., effective) changes between the amygdala and 3 large-scale resting-state networks involved in cognition. These networks are the default mode network, the salience network, and the central executive network. RESULTS We found a pattern of decreased top-down effective connectivity from these resting-state networks to the amygdala. Effective connectivity decreased within the default mode network and salience network but increased within the central executive network. These changes in effective connectivity were statistically associated with behavioral measures of altered cognition and emotion under the influence of psilocybin. CONCLUSIONS Our findings suggest that temporary amygdala signal attenuation is associated with mechanistic changes to resting-state network connectivity. These changes are significant for altered cognition and perception and suggest targets for research investigating the efficacy of psychedelic therapy for internalizing psychiatric disorders. More broadly, our study suggests the value of quantifying the brain's hierarchical organization using effective connectivity to identify important mechanisms for basic cognitive function and how they are integrated to give rise to subjective experiences.
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Affiliation(s)
- Devon Stoliker
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Leonardo Novelli
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Franz X Vollenweider
- Department of Psychiatry, Psychotherapy & Psychosomatics, Psychiatric University Hospital Zurich, Zurich, Switzerland
| | - Gary F Egan
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Katrin H Preller
- Department of Psychiatry, Psychotherapy & Psychosomatics, Psychiatric University Hospital Zurich, Zurich, Switzerland
| | - Adeel Razi
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia; Wellcome Centre for Human Neuroimaging, University College London, London, United Kingdom; CIFAR Azrieli Global Scholars Program, CIFAR, Toronto, Ontario, Canada.
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16
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Mortaheb S, Fort LD, Mason NL, Mallaroni P, Ramaekers JG, Demertzi A. Dynamic Functional Hyperconnectivity After Psilocybin Intake Is Primarily Associated With Oceanic Boundlessness. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:681-692. [PMID: 38588855 DOI: 10.1016/j.bpsc.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/28/2024] [Accepted: 04/01/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Psilocybin is a widely studied psychedelic substance that leads to the psychedelic state, a specific altered state of consciousness. To date, the relationship between the psychedelic state's neurobiological and experiential patterns remains undercharacterized because they are often analyzed separately. We investigated the relationship between neurobiological and experiential patterns after psilocybin by focusing on the link between dynamic cerebral connectivity and retrospective questionnaire assessment. METHODS Healthy participants were randomized to receive either psilocybin (n = 22) or placebo (n = 27) and scanned for 6 minutes in an eyes-open resting state during the peak subjective drug effect (102 minutes posttreatment) in ultrahigh field 7T magnetic resonance imaging. The 5-Dimensional Altered States of Consciousness Rating Scale was administered 360 minutes after drug intake. RESULTS Under psilocybin, there were alterations across all dimensions of the 5-Dimensional Altered States of Consciousness Rating Scale and widespread increases in averaged brain functional connectivity. Time-varying functional connectivity analysis unveiled a recurrent hyperconnected pattern characterized by low blood oxygen level-dependent signal amplitude, suggesting heightened cortical arousal. In terms of neuroexperiential links, canonical correlation analysis showed higher transition probabilities to the hyperconnected pattern with feelings of oceanic boundlessness and secondly with visionary restructuralization. CONCLUSIONS Psilocybin generates profound alterations at both the brain and the experiential levels. We suggest that the brain's tendency to enter a hyperconnected-hyperarousal pattern under psilocybin represents the potential to entertain variant mental associations. These findings illuminate the intricate interplay between brain dynamics and subjective experience under psilocybin, thereby providing insights into the neurophysiology and neuroexperiential qualities of the psychedelic state.
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Affiliation(s)
- Sepehr Mortaheb
- Physiology of Cognition, GIGA Research, CRC Human Imaging Unit, University of Liège, Liège, Belgium; Fund for Scientific Research FNRS, Brussels, Belgium
| | - Larry D Fort
- Physiology of Cognition, GIGA Research, CRC Human Imaging Unit, University of Liège, Liège, Belgium; Fund for Scientific Research FNRS, Brussels, Belgium
| | - Natasha L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Athena Demertzi
- Physiology of Cognition, GIGA Research, CRC Human Imaging Unit, University of Liège, Liège, Belgium; Fund for Scientific Research FNRS, Brussels, Belgium; Psychology & Neuroscience of Cognition, University of Liège, Liège, Belgium.
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17
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Gonçalves ÓF, Sayal J, Lisboa F, Palhares P. The experimental study of consciousness: Is psychology travelling back to the future? Int J Clin Health Psychol 2024; 24:100475. [PMID: 39021679 PMCID: PMC11253270 DOI: 10.1016/j.ijchp.2024.100475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 05/29/2024] [Indexed: 07/20/2024] Open
Abstract
It was with the promise of rendering an experimental approach to consciousness that psychology started its trajectory as an independent science more than 150 years ago. Here, we will posit that the neurosciences were instrumental in leading psychology to resume the study of consciousness by projecting an empirical agenda for the future. First, we will start by showing how scientists were able to venture into the consciousness of supposedly unconscious patients, opening the door for the identification of important neural correlates of distinct consciousness states. Then, we will describe how different technological advances and elegant experimental paradigms helped in establishing important neuronal correlates of global consciousness (i.e., being conscious at all), perceptual consciousness (i.e., being conscious of something), and self-consciousness (i.e., being conscious of itself). Finally, we will illustrate how the study of complex consciousness experiences may contribute to the clarification of the mechanisms associated with global consciousness, the relationship between perceptual and self-consciousness, and the interface among distinct self-consciousness domains. In closing, we will elaborate on the road ahead of us for re-establishing psychology as a science of consciousness.
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Affiliation(s)
| | - Joana Sayal
- Proaction Lab – CINEICC, Faculty of Psychology and Educational Sciences, University of Coimbra, Colégio de Jesus, R. Inácio Duarte 65, Coimbra 3000-481, Portugal
| | - Fábio Lisboa
- Proaction Lab – CINEICC, Faculty of Psychology and Educational Sciences, University of Coimbra, Colégio de Jesus, R. Inácio Duarte 65, Coimbra 3000-481, Portugal
| | - Pedro Palhares
- Proaction Lab – CINEICC, Faculty of Psychology and Educational Sciences, University of Coimbra, Colégio de Jesus, R. Inácio Duarte 65, Coimbra 3000-481, Portugal
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18
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Casanova AF, Ort A, Smallridge JW, Preller KH, Seifritz E, Vollenweider FX. The influence of psilocybin on subconscious and conscious emotional learning. iScience 2024; 27:110034. [PMID: 38883812 PMCID: PMC11177198 DOI: 10.1016/j.isci.2024.110034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/14/2024] [Accepted: 05/16/2024] [Indexed: 06/18/2024] Open
Abstract
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 study represents the first investigation into reinforcement learning with psilocybin. Across different dosages, psilocybin preserved learning effects and was statistically noninferior compared to placebo, while suggesting a higher exploratory behavior. Notably, the 20 mg group exhibited significantly better learning rates against the placebo group. Psilocybin induced inferior results with subconscious cues compared to placebo, and better results with conscious neutral cues in some conditions. These findings suggest that modulating serotonin signaling in the brain with psilocybin sufficiently preservers reinforcement learning.
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Affiliation(s)
- Andrea F Casanova
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Andres Ort
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - John W Smallridge
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Katrin H Preller
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Erich Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Franz X Vollenweider
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
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19
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Fischman L. Meaningfulness and attachment: what dreams, psychosis and psychedelic states tell us about our need for connection. Front Psychol 2024; 15:1413111. [PMID: 38966740 PMCID: PMC11223628 DOI: 10.3389/fpsyg.2024.1413111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 05/29/2024] [Indexed: 07/06/2024] Open
Abstract
The human need to find meaning in life and the human need for connection may be two sides of the same coin, a coin forged in the developmental crucible of attachment. Our need for meaningfulness can be traced to our developmental need for connection in the attachment relationship. The free energy principle dictates that in order to resist a natural tendency towards disorder self-organizing systems must generate models that predict the hidden causes of phenomenal experience. In other words, they must make sense of things. In both an evolutionary and ontogenetic sense, the narrative self develops as a model that makes sense of experience. However, the self-model skews the interpretation of experience towards that which is predictable, or already "known." One may say it causes us to "take things personally." Meaning is felt more acutely when defenses are compromised, when the narrative self is offline. This enables meaning-making that is less egocentrically motivated. Dreams, psychosis, and psychedelic states offer glimpses of how we make sense of things absent a coherent narrative self. This has implications for the way we understand such states, and lays bare the powerful reach of attachment in shaping what we experience as meaningful.
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Affiliation(s)
- Lawrence Fischman
- Department of Psychiatry, School of Medicine, Tufts University, Boston, MA, United States
- Fluence, South Portland, ME, United States
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20
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Pasculli G, Busan P, Jackson ES, Alm PA, De Gregorio D, Maguire GA, Goodwin GM, Gobbi G, Erritzoe D, Carhart-Harris RL. Psychedelics in developmental stuttering to modulate brain functioning: a new therapeutic perspective? Front Hum Neurosci 2024; 18:1402549. [PMID: 38962146 PMCID: PMC11221540 DOI: 10.3389/fnhum.2024.1402549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 05/27/2024] [Indexed: 07/05/2024] Open
Abstract
Developmental stuttering (DS) is a neurodevelopmental speech-motor disorder characterized by symptoms such as blocks, repetitions, and prolongations. Persistent DS often has a significant negative impact on quality of life, and interventions for it have limited efficacy. Herein, we briefly review existing research on the neurophysiological underpinnings of DS -specifically, brain metabolic and default mode/social-cognitive networks (DMN/SCN) anomalies- arguing that psychedelic compounds might be considered and investigated (e.g., in randomized clinical trials) for treatment of DS. The neural background of DS is likely to be heterogeneous, and some contribution from genetically determinants of metabolic deficiencies in the basal ganglia and speech-motor cortical regions are thought to play a role in appearance of DS symptoms, which possibly results in a cascade of events contributing to impairments in speech-motor execution. In persistent DS, the difficulties of speech are often linked to a series of associated aspects such as social anxiety and social avoidance. In this context, the SCN and DMN (also influencing a series of fronto-parietal, somato-motor, and attentional networks) may have a role in worsening dysfluencies. Interestingly, brain metabolism and SCN/DMN connectivity can be modified by psychedelics, which have been shown to improve clinical evidence of some psychiatric conditions (e.g., depression, post-traumatic stress disorder, etc.) associated with psychological constructs such as rumination and social anxiety, which also tend to be present in persistent DS. To date, while there have been no controlled trials on the effects of psychedelics in DS, anecdotal evidence suggests that these agents may have beneficial effects on stuttering and its associated characteristics. We suggest that psychedelics warrant investigation in DS.
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Affiliation(s)
- Giuseppe Pasculli
- Department of Computer, Control, and Management Engineering (DIAG), La Sapienza University, Rome, Italy
- Italian Society of Psychedelic Medicine (Società Italiana di Medicina Psichedelica–SIMePsi), Bari, Italy
| | | | - Eric S. Jackson
- Department of Communicative Sciences and Disorders, New York University, New York, NY, United States
| | - Per A. Alm
- Department of Communicative Sciences and Disorders, New York University, New York, NY, United States
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Danilo De Gregorio
- IRCCS, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Gerald A. Maguire
- School of Medicine, American University of Health Sciences, Signal Hill, CA, United States
- CenExel CIT Research, Riverside, CA, United States
| | - Guy M. Goodwin
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - David Erritzoe
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
| | - Robin L. Carhart-Harris
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
- Psychedelics Division, Neuroscape, University of California, San Francisco, CA, United States
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21
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Cardone P, Alnagger N, Annen J, Bicego A, Gosseries O, Martial C. Psychedelics and disorders of consciousness: the current landscape and the path forward. Neurosci Conscious 2024; 2024:niae025. [PMID: 38881630 PMCID: PMC11179162 DOI: 10.1093/nc/niae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 02/16/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024] Open
Abstract
Modern medicine has been shaken by the surge of psychedelic science that proposes a new approach to mitigate mental disorders, such as depression and post-traumatic stress disorder. Clinical trials to investigate whether psychedelic substances can treat psychiatric conditions are now underway, yet less discussion gravitates around their use in neurological disorders due to brain injury. One suggested implementation of brain-complexity enhancing psychedelics is to treat people with post-comatose disorders of consciousness (DoC). In this article, we discuss the rationale of this endeavour, examining possible outcomes of such experiments by postulating the existence of an optimal level of complexity. We consider the possible counterintuitive effects of both psychedelics and DoC on the functional connectivity of the default mode network and its possible impact on selfhood. We also elaborate on the role of computational modelling in providing complementary information to experimental studies, both contributing to our understanding of the treatment mechanisms and providing a path towards personalized medicine. Finally, we update the discourse surrounding the ethical considerations, encompassing clinical and scientific values.
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Affiliation(s)
- Paolo Cardone
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Naji Alnagger
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Jitka Annen
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Department of Data Analysis, University of Ghent, Henri Dunantlaan 1, Ghent 9000, Belgium
| | - Aminata Bicego
- Sensation and Perception Research Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Sensation and Perception Research Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Charlotte Martial
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
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22
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Stoliker D, Preller KH, Novelli L, Anticevic A, Egan GF, Vollenweider FX, Razi A. Neural mechanisms of psychedelic visual imagery. Mol Psychiatry 2024:10.1038/s41380-024-02632-3. [PMID: 38862674 DOI: 10.1038/s41380-024-02632-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/27/2024] [Accepted: 05/31/2024] [Indexed: 06/13/2024]
Abstract
Visual alterations under classic psychedelics can include rich phenomenological accounts of eyes-closed imagery. Preclinical evidence suggests agonism of the 5-HT2A receptor may reduce synaptic gain to produce psychedelic-induced imagery. However, this has not been investigated in humans. To infer the directed connectivity changes to visual connectivity underlying psychedelic visual imagery in healthy adults, a double-blind, randomised, placebo-controlled, cross-over study was performed, and dynamic causal modelling was applied to the resting state eyes-closed functional MRI scans of 24 subjects after administration of 0.2 mg/kg of the serotonergic psychedelic drug, psilocybin (magic mushrooms), or placebo. The effective connectivity model included the early visual area, fusiform gyrus, intraparietal sulcus, and inferior frontal gyrus. We observed a pattern of increased self-inhibition of both early visual and higher visual-association regions under psilocybin that was consistent with preclinical findings. We also observed a pattern of reduced inhibition from visual-association regions to earlier visual areas that indicated top-down connectivity is enhanced during visual imagery. The results were analysed with behavioural measures taken immediately after the scans, suggesting psilocybin-induced decreased sensitivity to neural inputs is associated with the perception of eyes-closed visual imagery. The findings inform our basic and clinical understanding of visual perception. They reveal neural mechanisms that, by affecting balance, may increase the impact of top-down feedback connectivity on perception, which could contribute to the visual imagery seen with eyes-closed during psychedelic experiences.
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Affiliation(s)
- Devon Stoliker
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia.
| | - Katrin H Preller
- Department of Psychiatry, Psychotherapy & Psychosomatics, University Hospital for Psychiatry, Zurich, Switzerland
| | - Leonardo Novelli
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Alan Anticevic
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Gary F Egan
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
- Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
| | - Franz X Vollenweider
- Department of Psychiatry, Psychotherapy & Psychosomatics, University Hospital for Psychiatry, Zurich, Switzerland
| | - Adeel Razi
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
- Monash Biomedical Imaging, Monash University, Clayton, VIC, Australia
- Wellcome Centre for Human Neuroimaging, UCL, London, UK
- CIFAR Azrieli Global Scholars Program, CIFAR, Toronto, ON, Canada
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23
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Szafoni S, Gręblowski P, Grabowska K, Więckiewicz G. Unlocking the healing power of psilocybin: an overview of the role of psilocybin therapy in major depressive disorder, obsessive-compulsive disorder and substance use disorder. Front Psychiatry 2024; 15:1406888. [PMID: 38919636 PMCID: PMC11196758 DOI: 10.3389/fpsyt.2024.1406888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/21/2024] [Indexed: 06/27/2024] Open
Abstract
Resistance to traditional treatment methods is still a major obstacle in modern psychiatry. As a result, several studies are currently being conducted to find effective alternatives to traditional therapies. One of these alternatives is psilocybin, a psychedelic substance that has been tested in clinical trials as an adjunct to psychotherapy. These studies focus on patients with major depressive disorder (MDD), obsessive-compulsive disorder (OCD) and substance use disorder (SUD), particularly alcohol and nicotine dependence. This article looks at the current understanding of psilocybin, including data from clinical trials conducted, psilocybin's mechanism of action, its safety and the level of risk associated with it.
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Affiliation(s)
- Sandra Szafoni
- Students’ Scientific Circle in Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Piotr Gręblowski
- Students’ Scientific Circle in Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Klaudia Grabowska
- Students’ Scientific Circle in Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Gniewko Więckiewicz
- Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
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24
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Jylkkä J, Krabbe A, Jern P. Endorsement of metaphysical idealism mediates a link between past use of psychedelics and wellbeing. Sci Rep 2024; 14:13276. [PMID: 38858435 PMCID: PMC11164882 DOI: 10.1038/s41598-024-63687-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 05/31/2024] [Indexed: 06/12/2024] Open
Abstract
It has been proposed that psychedelics promote wellbeing through spiritual-type transformations, involving changes in metaphysical beliefs. Past empirical research shows a link between the use of psychedelics and the endorsement of non-physicalist metaphysical beliefs. However, non-physicalist beliefs encompass a wide range of metaphysical ideas, and their links to wellbeing and psychedelics use remain unclear. We utilized a cross-sectional Internet survey to probe the metaphysical beliefs of participants (N = 701) with past experience of classical psychedelics, using a novel 42-item questionnaire (Core Metaphysical Beliefs, CMB), encompassing a wide range of metaphysical beliefs. Factor analysis of CMB revealed two factors, Idealism and Materialism. In network analyses, Idealism was linked to psychological insight in a past psychedelic experience (E = 0.24) and average use of psychedelics (E = 0.16), and predicted wellbeing (Es = 0.13 and 0.22). Mediation analyses showed an indirect link from past psychedelics use through Idealism to wellbeing (ps ≤ .005). Non-Physicalist Beliefs or Materialism were not significant mediators. The results indicate that Idealism specifically, not non-physicalist beliefs generally, mediate a link between the use of psychedelics and wellbeing. Future research is required to establish whether the link is causal, and to understand what the Idealism factor means.
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Affiliation(s)
- Jussi Jylkkä
- Department of Psychology, Åbo Akademi University, Turku, Finland.
| | - Andreas Krabbe
- Department of Psychology, Åbo Akademi University, Turku, Finland
| | - Patrick Jern
- Department of Psychology, Åbo Akademi University, Turku, Finland
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25
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Peled-Avron L, Aday JS, Kalafateli AL, Hamilton HK, Woolley JD. Editorial: Down the rabbit hole - the psychological and neural mechanisms of psychedelic compounds and their use in treating mental health and medical conditions. Front Psychiatry 2024; 15:1431389. [PMID: 38915850 PMCID: PMC11194731 DOI: 10.3389/fpsyt.2024.1431389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Accepted: 05/20/2024] [Indexed: 06/26/2024] Open
Affiliation(s)
- Leehe Peled-Avron
- Department of Psychology and Gonda Interdisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA, United States
- Department of Psychiatry, San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States
| | - Jacob S. Aday
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States
| | | | - Holly K. Hamilton
- Department of Psychiatry & Behavioral Sciences, University of Minnesota, Minneapolis, MN, United States
- Mental Health Service, Minneapolis VA Health Care System, Minneapolis, MN, United States
| | - Joshua D. Woolley
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA, United States
- Department of Psychiatry, San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States
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26
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Ramos L, Vicente SG. The effects of psilocybin on cognition and emotional processing in healthy adults and adults with depression: a systematic literature review. J Clin Exp Neuropsychol 2024:1-29. [PMID: 38842300 DOI: 10.1080/13803395.2024.2363343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 05/30/2024] [Indexed: 06/07/2024]
Abstract
INTRODUCTION Psilocybin, a naturally occurring serotonergic agonist in some mushroom species, has shown promise as a novel, fast-acting pharmacotherapy seeking to overcome the limitations of conventional first-line antidepressants. Studying psilocybin effects on cognition and emotional processing may help to clarify the mechanisms underlying the therapeutic potential of psilocybin and may also support studies with people suffering from depression. Thus, this review aims to provide a comprehensive overview of the current literature regarding the effects of psilocybin on these two key areas in both healthy and depressed populations. METHOD A systematic search was performed on 29 January 2024, in the PubMed, EBSCOhost, Web of Science and SCOPUS databases. After duplicates removal, study selection was conducted considering pre-specified criteria. Data extraction was then performed. The quality assessment of the studies was carried out using the Cochrane Collaboration tools for randomized (RoB 2.0) and non-randomized (ROBINS-I) controlled trials. RESULTS Twenty articles were included, with 18 targeting healthy adults and two adults with depression. Results point to impairments within attentional and inhibitory processes, and improvements in the domains of creativity and social cognition in healthy individuals. In the population with depression, only cognitive flexibility and emotional recognition were affected, both being enhanced. The comparison of outcomes from both populations proved limited. CONCLUSIONS Psilocybin acutely alters several cognitive domains, with a localized rather than global focus, in a dose- and time-dependent manner. However, the significant methodological constraints call for further research, in the context of depression and with standardized protocols, with longitudinal studies also imperative.
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Affiliation(s)
- Laura Ramos
- Faculty of Psychology and Educational Sciences, University of Porto, Porto, Portugal
| | - Selene G Vicente
- Faculty of Psychology and Educational Sciences, University of Porto, Porto, Portugal
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27
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Bornemann J, Close JB, Ahmad K, Barba T, Godfrey K, Macdonald L, Erritzoe D, Nutt D, Carhart-Harris R. Study protocol for "Psilocybin in patients with fibromyalgia: brain biomarkers of action". Front Psychiatry 2024; 15:1320780. [PMID: 38983371 PMCID: PMC11232672 DOI: 10.3389/fpsyt.2024.1320780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 03/04/2024] [Indexed: 07/11/2024] Open
Abstract
Background Chronic pain is a leading cause of disability worldwide. Fibromyalgia is a particularly debilitating form of widespread chronic pain. Fibromyalgia remains poorly understood, and treatment options are limited or moderately effective at best. Here, we present a protocol for a mechanistic study investigating the effects of psychedelic-assisted-therapy in a fibromyalgia population. The principal focus of this trial is the central mechanism(s) of psilocybin-therapy i.e., in the brain and on associated mental schemata, primarily captured by electroencephalography (EEG) recordings of the acute psychedelic state, plus pre and post Magnetic Resonance Imaging (MRI). Methods Twenty participants with fibromyalgia will complete 8 study visits over 8 weeks. This will include two dosing sessions where participants will receive psilocybin at least once, with doses varying up to 25mg. Our primary outcomes are 1) Lempel-Ziv complexity (LZc) recorded acutely using EEG, and the 2) the (Brief Experiential Avoidance Questionnaire (BEAQ) measured at baseline and primary endpoint. Secondary outcomes will aim to capture broad aspects of the pain experience and related features through neuroimaging, self-report measures, behavioural paradigms, and qualitative interviews. Pain Symptomatology will be measured using the Brief Pain Inventory Interference Subscale (BPI-IS), physical and mental health-related function will be measured using the 36-Item Short Form Health Survey (SF-36). Further neurobiological investigations will include functional MRI (fMRI) and diffusion tensor imaging (changes from baseline to primary endpoint), and acute changes in pre- vs post-acute spontaneous brain activity - plus event-related potential functional plasticity markers, captured via EEG. Discussion The results of this study will provide valuable insight into the brain mechanisms involved in the action of psilocybin-therapy for fibromyalgia with potential implications for the therapeutic action of psychedelic-therapy more broadly. It will also deliver essential data to inform the design of a potential subsequent RCT.
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Affiliation(s)
- Julia Bornemann
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - James B. Close
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - Kirran Ahmad
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - Tommaso Barba
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - Kate Godfrey
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - Lauren Macdonald
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - David Erritzoe
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - David Nutt
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
| | - Robin Carhart-Harris
- Centre for Psychedelic Research, Department of Brain Science, Imperial College London, London, United Kingdom
- Psychedelics Division, Neurology, Psychiatry and Behavioural Sciences Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
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28
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Lord B, Sanguinetti JL, Ruiz L, Miskovic V, Segre J, Young S, Fini ME, Allen JJB. Transcranial focused ultrasound to the posterior cingulate cortex modulates default mode network and subjective experience: an fMRI pilot study. Front Hum Neurosci 2024; 18:1392199. [PMID: 38895168 PMCID: PMC11184145 DOI: 10.3389/fnhum.2024.1392199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024] Open
Abstract
Background Transcranial focused ultrasound (TFUS) is an emerging neuromodulation tool for temporarily altering brain activity and probing network functioning. The effects of TFUS on the default mode network (DMN) are unknown. Objective The study examined the effects of transcranial focused ultrasound (TFUS) on the functional connectivity of the default mode network (DMN), specifically by targeting the posterior cingulate cortex (PCC). Additionally, we investigated the subjective effects of TFUS on mood, mindfulness, and self-related processing. Methods The study employed a randomized, single-blind design involving 30 healthy subjects. Participants were randomly assigned to either the active TFUS group or the sham TFUS group. Resting-state functional magnetic resonance imaging (rs-fMRI) scans were conducted before and after the TFUS application. To measure subjective effects, the Toronto Mindfulness Scale, the Visual Analog Mood Scale, and the Amsterdam Resting State Questionnaire were administered at baseline and 30 min after sonication. The Self Scale and an unstructured interview were also administered 30 min after sonication. Results The active TFUS group exhibited significant reductions in functional connectivity along the midline of the DMN, while the sham TFUS group showed no changes. The active TFUS group demonstrated increased state mindfulness, reduced Global Vigor, and temporary alterations in the sense of ego, sense of time, and recollection of memories. The sham TFUS group showed an increase in state mindfulness, too, with no other subjective effects. Conclusions TFUS targeted at the PCC can alter DMN connectivity and cause changes in subjective experience. These findings support the potential of TFUS to serve both as a research tool and as a potential therapeutic intervention.
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Affiliation(s)
- Brian Lord
- SEMA Lab, Psychology Department, Center for Consciousness Studies, University of Arizona, Tucson, AZ, United States
| | - Joseph L. Sanguinetti
- SEMA Lab, Psychology Department, Center for Consciousness Studies, University of Arizona, Tucson, AZ, United States
- Sanmai Technologies, PBC, Sunnyvale, CA, United States
| | - Lisannette Ruiz
- SEMA Lab, Psychology Department, Center for Consciousness Studies, University of Arizona, Tucson, AZ, United States
- Sanmai Technologies, PBC, Sunnyvale, CA, United States
| | | | - Joel Segre
- X, the Moonshot Factory, Mountain View, CA, United States
| | - Shinzen Young
- SEMA Lab, Psychology Department, Center for Consciousness Studies, University of Arizona, Tucson, AZ, United States
| | - Maria E. Fini
- SEMA Lab, Psychology Department, Center for Consciousness Studies, University of Arizona, Tucson, AZ, United States
| | - John J. B. Allen
- SEMA Lab, Psychology Department, Center for Consciousness Studies, University of Arizona, Tucson, AZ, United States
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29
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Szigeti B, Weiss B, Rosas FE, Erritzoe D, Nutt D, Carhart-Harris R. Assessing expectancy and suggestibility in a trial of escitalopram v. psilocybin for depression. Psychol Med 2024; 54:1717-1724. [PMID: 38247730 DOI: 10.1017/s0033291723003653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
BACKGROUND To investigate the association between pre-trial expectancy, suggestibility, and response to treatment in a trial of escitalopram and investigational drug, COMP360, psilocybin, in the treatment of major depressive disorder (ClinicalTrials.gov registration: NCT03429075). METHODS We used data (n = 55) from our recent double-blind, parallel-group, randomized head-to-head comparison trial of escitalopram and investigational drug, COMP360, psilocybin. Mixed linear models were used to investigate the association between pre-treatment efficacy-related expectations, as well as baseline trait suggestibility and absorption, and therapeutic response to both escitalopram and COMP360 psilocybin. RESULTS Patients had significantly higher expectancy for psilocybin relative to escitalopram; however, expectancy for escitalopram was associated with improved therapeutic outcomes to escitalopram, expectancy for psilocybin was not predictive of response to psilocybin. Separately, we found that pre-treatment trait suggestibility was associated with therapeutic response in the psilocybin arm, but not in the escitalopram arm. CONCLUSIONS Overall, our results suggest that psychedelic therapy may be less vulnerable to expectancy biases than previously suspected. The relationship between baseline trait suggestibility and response to psilocybin therapy implies that highly suggestible individuals may be primed for response to this treatment.
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Affiliation(s)
- Balázs Szigeti
- Centre for Psychedelic Research, Imperial College London, UK
- Department of Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, USA
| | - Brandon Weiss
- Centre for Psychedelic Research, Imperial College London, UK
| | - Fernando E Rosas
- Centre for Psychedelic Research, Imperial College London, UK
- Centre for Complexity Science, Imperial College London, UK
- Department of Informatics, University of Sussex, Brighton, UK
- Centre for Eudaimonia and Human Flourishing, University of Oxford, Oxford, UK
| | - David Erritzoe
- Centre for Psychedelic Research, Imperial College London, UK
| | - David Nutt
- Centre for Psychedelic Research, Imperial College London, UK
| | - Robin Carhart-Harris
- Depts. of Neurology, Psychiatry and Behavioral Sciences, University of California San Francisco, San Francisco, USA
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30
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Murray CH, Frohlich J, Haggarty CJ, Tare I, Lee R, de Wit H. Neural complexity is increased after low doses of LSD, but not moderate to high doses of oral THC or methamphetamine. Neuropsychopharmacology 2024; 49:1120-1128. [PMID: 38287172 PMCID: PMC11109226 DOI: 10.1038/s41386-024-01809-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/07/2024] [Accepted: 01/17/2024] [Indexed: 01/31/2024]
Abstract
Neural complexity correlates with one's level of consciousness. During coma, anesthesia, and sleep, complexity is reduced. During altered states, including after lysergic acid diethylamide (LSD), complexity is increased. In the present analysis, we examined whether low doses of LSD (13 and 26 µg) were sufficient to increase neural complexity in the absence of altered states of consciousness. In addition, neural complexity was assessed after doses of two other drugs that significantly altered consciousness and mood: delta-9-tetrahydrocannabinol (THC; 7.5 and 15 mg) and methamphetamine (MA; 10 and 20 mg). In three separate studies (N = 73; 21, LSD; 23, THC; 29, MA), healthy volunteers received placebo or drug in a within-subjects design over three laboratory visits. During anticipated peak drug effects, resting state electroencephalography (EEG) recorded Limpel-Ziv complexity and spectral power. LSD, but not THC or MA, dose-dependently increased neural complexity. LSD also reduced delta and theta power. THC reduced, and MA increased, alpha power, primarily in frontal regions. Neural complexity was not associated with any subjective drug effect; however, LSD-induced reductions in delta and theta were associated with elation, and THC-induced reductions in alpha were associated with altered states. These data inform relationships between neural complexity, spectral power, and subjective states, demonstrating that increased neural complexity is not necessary or sufficient for altered states of consciousness. Future studies should address whether greater complexity after low doses of LSD is related to cognitive, behavioral, or therapeutic outcomes, and further examine the role of alpha desynchronization in mediating altered states of consciousness.
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Affiliation(s)
- Conor H Murray
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
- Department of Psychiatry and Biobehavioral Sciences, University of Los Angeles, California, 760 Westwood Plaza, Los Angeles, CA, 90024, USA.
| | - Joel Frohlich
- Institute for Neuromodulation and Neurotechnology, University of Tübingen, Otfried-Müller-Straße 45, 72076, Tübingen, Germany
- Institute for Advanced Consciousness Studies, Santa Monica, California; 2811 Wilshire Blvd # 510, Santa Monica, CA, 90403, USA
| | - Connor J Haggarty
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Ilaria Tare
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
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Lasch A, Schweikert T, Dora E, Kolb T, Schurig HL, Walther A. [Psilocybin-Assisted Treatment of Depression, Anxiety and Substance use Disorders: Neurobiological Basis and Clinical Application]. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2024; 92:230-245. [PMID: 37207669 DOI: 10.1055/a-2046-5202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Successful therapy of mental disorders is very important in view of the high level of suffering of those affected. Since established pharmaceutical and psychotherapeutic approaches do not lead to the desired improvement in all cases, complementary or alternative treatment methods are intensively researched. Psilocybin-assisted psychotherapy seems particularly promising, and has been approved in the USA for larger clinical trials. Psilocybin belongs to the group of psychedelics and influences psychological experiences. In assisted therapy, psilocybin is administered in controlled doses under medical supervision to patients with different mental disorders. In the studies conducted so far, longer-term positive effects could be shown after just one or a few doses. In order to provide a better understanding of the potential therapeutic mechanisms, this article will first describe neurobiological and psychological effects of psilocybin. To better assess the potential of psilocybin-assisted psychotherapy for various disorders, clinical studies conducted so far with patients administered psilocybin are reviewed.
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Affiliation(s)
- Anna Lasch
- Biopsychologie, Technische Universität Dresden, Dresden, Germany
| | - Timo Schweikert
- Psychotherapie und Systemneurowissenschaften, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Eva Dora
- Biopsychologie, Technische Universität Dresden, Dresden, Germany
| | - Theresa Kolb
- Universitätsklinikum Carl Gustav Carus Dresden, Division Psychological and Social Medicine and Developmental Neuroscience, Dresden, Germany
| | - Hanne Lilian Schurig
- Universitätsklinikum Carl Gustav Carus Dresden, Division Psychological and Social Medicine and Developmental Neuroscience, Dresden, Germany
| | - Andreas Walther
- Klinische Psychologie und Psychotherapie, Universität Zürich Psychologisches Institut, Zurich, Switzerland
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Yang WF, Sparby T, Wright M, Kim E, Sacchet MD. Volitional mental absorption in meditation: Toward a scientific understanding of advanced concentrative absorption meditation and the case of jhana. Heliyon 2024; 10:e31223. [PMID: 38803854 PMCID: PMC11129010 DOI: 10.1016/j.heliyon.2024.e31223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/04/2024] [Accepted: 05/13/2024] [Indexed: 05/29/2024] Open
Abstract
Meditation has been integral to human culture for millennia, deeply rooted in various spiritual and contemplative traditions. While the field of contemplative science has made significant steps toward understanding the effects of meditation on health and well-being, there has been little study of advanced meditative states, including those achieved through intense concentration and absorption. We refer to these types of states as advanced concentrative absorption meditation (ACAM), characterized by absorption with the meditation object leading to states of heightened attention, clarity, energy, effortlessness, and bliss. This review focuses on a type of ACAM known as jhana (ACAM-J) due to its well-documented history, systematic practice approach, recurring phenomenological themes, and growing popularity among contemplative scientists and more generally in media and society. ACAM-J encompasses eight layers of deep concentration, awareness, and internal experiences. Here, we describe the phenomenology of ACAM-J and present evidence from phenomenological and neuroscientific studies that highlight their potential applications in contemplative practices, psychological sciences, and therapeutics. We additionally propose theoretical ACAM-J frameworks grounded in current cognitive neuroscientific understanding of meditation and ancient contemplative traditions. We aim to stimulate further research on ACAM more broadly, encompassing advanced meditation including meditative development and meditative endpoints. Studying advanced meditation including ACAM, and specific practices such as ACAM-J, can potentially revolutionize our understanding of consciousness and applications for mental health.
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Affiliation(s)
- Winson F.Z. Yang
- Meditation Research Program, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Terje Sparby
- Steiner University College, 0260, Oslo, Norway
- Department of Psychology and Psychotherapy, Witten/Herdecke University, 58448, Witten, Germany
- Integrated Curriculum for Anthroposophic Psychology, Witten/Herdecke University, 58448, Witten, Germany
| | - Malcolm Wright
- School of Communication, Journalism and Marketing, Massey University, Albany, New Zealand
| | - Eunmi Kim
- Center for Contemplative Science, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Matthew D. Sacchet
- Meditation Research Program, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Vohryzek J, Luppi AI, Atasoy S, Deco G, Carhart-Harris RL, Timmermann C, Kringelbach ML. Time-resolved coupling between connectome harmonics and subjective experience under the psychedelic DMT. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596410. [PMID: 38853985 PMCID: PMC11160714 DOI: 10.1101/2024.05.30.596410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Exploring the intricate relationship between brain's structure and function, and how this affects subjective experience is a fundamental pursuit in neuroscience. Psychedelic substances offer a unique insight into the influences of specific neurotransmitter systems on perception, cognition and consciousness. Specifically, their impact on brain function propagates across the structural connectome - a network of white matter pathways linking different regions. To comprehensively grasp the effects of psychedelic compounds on brain function, we used a theoretically rigorous framework known as connectome harmonic decomposition. This framework provides a robust method to characterize how brain function intricately depends on the organized network structure of the human connectome. We show that the connectome harmonic repertoire under DMT is reshaped in line with other reported psychedelic compounds - psilocybin, LSD and ketamine. Furthermore, we show that the repertoire entropy of connectome harmonics increases under DMT, as with those other psychedelics. Importantly, we demonstrate for the first time that measures of energy spectrum difference and repertoire entropy of connectome harmonics indexes the intensity of subjective experience of the participants in a time-resolved manner reflecting close coupling between connectome harmonics and subjective experience.
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Affiliation(s)
- Jakub Vohryzek
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, United Kingdom
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Andrea I. Luppi
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, United Kingdom
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
- St John’s College, University of Cambridge, Cambridge, United Kingdom
- Division of Information Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Selen Atasoy
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, United Kingdom
- Center for Music in the Brain, Aarhus University, Aarhus, Denmark
| | - Gustavo Deco
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
- Institució Catalana de la Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona, 08010, Spain
| | - Robin L. Carhart-Harris
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, United Kingdom
- Departments of Neurology and Psychiatry, University of California San Francisco, San Francisco, USA
| | - Christopher Timmermann
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Morten L. Kringelbach
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, United Kingdom
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
- Center for Music in the Brain, Aarhus University, Aarhus, Denmark
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Jackson ES, Goldway N, Gerlach-Houck H, Gold ND. Stutterers' experiences on classic psychedelics: A preliminary self-report study. JOURNAL OF FLUENCY DISORDERS 2024; 81:106062. [PMID: 38833909 DOI: 10.1016/j.jfludis.2024.106062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 06/06/2024]
Abstract
Stuttering poses challenges to social, occupational, and educational aspects of life. Traditional behavioral therapies can be helpful but effects are often limited. Pharmaceutical treatments have been explored but there are no FDA-approved treatments for stuttering. Interest has grown in the potential use of classic psychedelics, including psilocybin and LSD, which have shown effectiveness in treating disorders with similar symptoms (e.g., anxiety, depression, PTSD). The potential effects of psychedelics on stuttering have not been explored. We conducted a preliminary investigation of self-identified stutterers who report their experiences taking classic psychedelics on the online messaging forum, Reddit. We qualitatively analyzed 114 publicly available posts, extracting meaningful units and assigning descriptor codes inductively. We then deductively organized responses into an established framework of psychedelics which includes behavioral, emotional, cognitive, belief-based, and social effects. These effects were subsequently grouped under organizing themes (positive, negative, neutral). Descriptive statistics revealed that the majority of users (74.0%) reported positive overall short-term effects particularly related to behavioral and emotional change (e.g., reduced stuttering and anxiety), but negative (9.6%), mixed (positive and negative; 4.8%), and neutral overall experiences (11.6%) were also reported. The results support the possibility that psychedelics may impact stuttering, but caution must be applied in their interpretation given the entirely uncontrolled research setting and potential adverse health effects of psychedelics as reported elsewhere. While these results do not encourage the use of psychedelics by stutterers, they suggest that future work could examine the impact of psychedelics on stuttering under supervised and in clinically controlled settings.
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Affiliation(s)
- Eric S Jackson
- Department of Communicative Sciences and Disorders, New York University, USA.
| | - Noam Goldway
- Department of Psychology, New York University, USA
| | - Hope Gerlach-Houck
- Department of Speech, Language, and Hearing Sciences, Western Michigan University, USA
| | - Noah D Gold
- Department of Psychiatry, New York University Langone Health, USA
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Rogers SA, Heller EA, Corder G. Psilocybin-enhanced fear extinction linked to bidirectional modulation of cortical ensembles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.04.578811. [PMID: 38352491 PMCID: PMC10862786 DOI: 10.1101/2024.02.04.578811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The serotonin 2 receptor (5HT2R) agonist psilocybin displays rapid and persistent therapeutic efficacy across neuropsychiatric disorders characterized by cognitive inflexibility. However, the impact of psilocybin on patterns of neural activity underlying sustained changes in behavioral flexibility has not been characterized. To test the hypothesis that psilocybin enhances behavioral flexibility by altering activity in cortical neural ensembles, we performed longitudinal single-cell calcium imaging in the retrosplenial cortex across a five-day trace fear learning and extinction assay. A single dose of psilocybin induced ensemble turnover between fear learning and extinction days while oppositely modulating activity in fear- and extinction- active neurons. The acute suppression of fear-active neurons and delayed recruitment of extinction-active neurons were predictive of psilocybin-enhanced fear extinction. A computational model revealed that acute inhibition of fear-active neurons by psilocybin is sufficient to explain its neural and behavioral effects days later. These results align with our hypothesis and introduce a new mechanism involving the suppression of fear-active populations in the retrosplenial cortex.
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Affiliation(s)
- Sophie A. Rogers
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elizabeth A. Heller
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gregory Corder
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Mastrovito D, Liu YH, Kusmierz L, Shea-Brown E, Koch C, Mihalas S. Transition to chaos separates learning regimes and relates to measure of consciousness in recurrent neural networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594236. [PMID: 38798582 PMCID: PMC11118502 DOI: 10.1101/2024.05.15.594236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Recurrent neural networks exhibit chaotic dynamics when the variance in their connection strengths exceed a critical value. Recent work indicates connection variance also modulates learning strategies; networks learn "rich" representations when initialized with low coupling and "lazier" solutions with larger variance. Using Watts-Strogatz networks of varying sparsity, structure, and hidden weight variance, we find that the critical coupling strength dividing chaotic from ordered dynamics also differentiates rich and lazy learning strategies. Training moves both stable and chaotic networks closer to the edge of chaos, with networks learning richer representations before the transition to chaos. In contrast, biologically realistic connectivity structures foster stability over a wide range of variances. The transition to chaos is also reflected in a measure that clinically discriminates levels of consciousness, the perturbational complexity index (PCIst). Networks with high values of PCIst exhibit stable dynamics and rich learning, suggesting a consciousness prior may promote rich learning. The results suggest a clear relationship between critical dynamics, learning regimes and complexity-based measures of consciousness.
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van Lutterveld R, Chowdhury A, Ingram DM, Sacchet MD. Neurophenomenological Investigation of Mindfulness Meditation "Cessation" Experiences Using EEG Network Analysis in an Intensively Sampled Adept Meditator. Brain Topogr 2024:10.1007/s10548-024-01052-4. [PMID: 38703334 DOI: 10.1007/s10548-024-01052-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 04/12/2024] [Indexed: 05/06/2024]
Abstract
Mindfulness meditation is a contemplative practice that is informed by Buddhism. It has been proven effective for improving mental and physical health in clinical and non-clinical contexts. To date, mainstream dialogue and scientific research on mindfulness has focused primarily on short-term mindfulness training and applications of mindfulness for reducing stress. Understanding advanced mindfulness practice has important implications for mental health and general wellbeing. According to Theravada Buddhist meditation, a "cessation" event is a dramatic experience of profound clarity and equanimity that involves a complete discontinuation in experience, and is evidence of mastery of mindfulness meditation. Thirty-seven cessation events were captured in a single intensively sampled advanced meditator (over 6,000 h of retreat mindfulness meditation training) while recording electroencephalography (EEG) in 29 sessions between November 12, 2019 and March 11, 2020. Functional connectivity and network integration were assessed from 40 s prior to cessations to 40 s after cessations. From 21 s prior to cessations there was a linear decrease in large-scale functional interactions at the whole-brain level in the alpha band. In the 40 s following cessations these interactions linearly returned to prior levels. No modulation of network integration was observed. The decrease in whole-brain functional connectivity was underlain by frontal to left temporal and to more posterior decreases in connectivity, while the increase was underlain by wide-spread increases in connectivity. These results provide neuroscientific evidence of large-scale modulation of brain activity related to cessation events that provides a foundation for future studies of advanced meditation.
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Affiliation(s)
- Remko van Lutterveld
- Brain Research and Innovation Centre and Department of Psychiatry, Ministry of Defence and University Medical Center, Utrecht, The Netherlands.
| | - Avijit Chowdhury
- Center for Depression, Anxiety, and Stress Research, McLean Hospital, Harvard Medical School, Belmont, MA, USA
| | | | - Matthew D Sacchet
- Center for Depression, Anxiety, and Stress Research, McLean Hospital, Harvard Medical School, Belmont, MA, USA
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Peill J, Marguilho M, Erritzoe D, Barba T, Greenway KT, Rosas F, Timmermann C, Carhart-Harris R. Psychedelics and the 'inner healer': Myth or mechanism? J Psychopharmacol 2024; 38:417-424. [PMID: 38605658 PMCID: PMC11102647 DOI: 10.1177/02698811241239206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
BACKGROUND Reference to an intrinsic healing mechanism or an 'inner healer' is commonplace amongst psychedelic drug-using cultures. The 'inner healer' refers to the belief that psychedelic compounds, plants or concoctions have an intrinsically regenerative action on the mind and brain, analogous to intrinsic healing mechanisms within the physical body, for example, after sickness or injury. AIMS Here, we sought to test and critique this idea by devising a single subjective rating item pertaining to perceived 'inner healing' effects. METHODS The item was issued to 59 patients after a single high (25 mg, n = 30) or 'placebo' (1 mg, n = 29) dose of psilocybin in a double-blind randomised controlled trial of psilocybin for depression. RESULTS Inner healer scores were higher after the high versus placebo dose of psilocybin (t = 3.88, p < 0.001). Within the high-dose sub-sample only, inner healer scores predicted improved depressive symptomatology at 2 weeks post-dosing. CONCLUSIONS The principle of activating inner healing mechanisms via psychedelics is scientifically nascent; however, this study takes a positivist and pragmatic step forward, asking whether it warrants further examination.
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Affiliation(s)
- Joseph Peill
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Miriam Marguilho
- Division of Psychiatry, Lisbon Psychiatric Hospital Centre, Lisbon, Portugal
| | - David Erritzoe
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Tommaso Barba
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Kyle T Greenway
- Division of Psychiatry, Lisbon Psychiatric Hospital Centre, Lisbon, Portugal
- Faculty of Medicine, Department of Psychiatry, McGill University, Ludmer Research and Training Building, Montréal, QC, Canada
- Lady Davis Institute, Jewish General Hospital, Montréal, QC, Canada
| | - Fernando Rosas
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Centre for Complexity Science, Imperial College London, London, UK
- Department of Informatics, University of Sussex, Brighton, UK
- Centre for Eudaimonia and Human Flourishing, University of Oxford, Oxford, UK
| | - Christopher Timmermann
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Robin Carhart-Harris
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Departments of Neurology and Psychiatry, Carhart-Harris Lab, University of California San Francisco, San Francisco, CA, USA
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Hicks M, Giguere O. Vitalism and Naturopathy in Psychedelic Medicine. Integr Med (Encinitas) 2024; 23:54-58. [PMID: 38911446 PMCID: PMC11193403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Psychedelic therapy is witnessing a rapid rise in popularity both in clinical research and in the greater culture. Since it involves the use of drugs, psychology, and spirituality, professionals from a variety of backgrounds such as physicians, psychotherapists, chaplains, etc. are increasingly becoming interested or directly involved. In this article, the authors describe why naturopathic doctors, with additional training, are well suited to provide psychedelic therapy. Naturopathy is rooted in the non-materialistic metaphysics of vitalism, which is consistent with the concept of inner healing intelligence, which is widely accepted in the psychedelic therapy community. In addition to the compatible foundational philosophies, naturopaths also possess a wide range of clinical skills including herbalism, pharmacology, and counseling, among others, that can be directly applied to psychedelic therapy and integration.
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Lewis EC, Jaeger A, Girn M, Omene E, Brendle M, Argento E. Exploring psychedelic-assisted therapy in the treatment of functional seizures: A review of underlying mechanisms and associated brain networks. J Psychopharmacol 2024; 38:407-416. [PMID: 38654554 PMCID: PMC11102649 DOI: 10.1177/02698811241248395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Functional seizures (FS), the most common subtype of functional neurological disorder (FND), cause serious neurological disability and significantly impact quality of life. Characterized by episodic disturbances of functioning that resemble epileptic seizures, FS coincide with multiple comorbidities and are treated poorly by existing approaches. Novel treatment approaches are sorely needed. Notably, mounting evidence supports the safety and efficacy of psychedelic-assisted therapy (PAT) for several psychiatric conditions, motivating investigations into whether this efficacy also extends to neurological disorders. Here, we synthesize past empirical findings and frameworks to construct a biopsychosocial mechanistic argument for the potential of PAT as a treatment for FS. In doing so, we highlight FS as a well-defined cohort to further understand the large-scale neural mechanisms underpinning PAT. Our synthesis is guided by a complexity science perspective which we contend can afford unique mechanistic insight into both FS and PAT, as well as help bridge these two domains. We also leverage this perspective to propose a novel analytic roadmap to identify markers of FS diagnostic specificity and treatment success. This endeavor continues the effort to bridge clinical neurology with psychedelic medicine and helps pave the way for a new field of psychedelic neurology.
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Affiliation(s)
- Evan Cole Lewis
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, ON, Canada
| | | | - Manesh Girn
- Neuroscape, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | | | - Madeline Brendle
- Numinus Wellness Inc., Vancouver, BC, Canada
- Health Outcomes Division, College of Pharmacy, University of Texas at Austin, Austin, TX, USA
| | - Elena Argento
- Numinus Wellness Inc., Vancouver, BC, Canada
- Department of Psychology, University of British Columbia, Kelowna, BC, Canada
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41
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Vohryzek J, Cabral J, Timmermann C, Atasoy S, Roseman L, Nutt DJ, Carhart-Harris RL, Deco G, Kringelbach ML. The flattening of spacetime hierarchy of the N,N-dimethyltryptamine brain state is characterized by harmonic decomposition of spacetime (HADES) framework. Natl Sci Rev 2024; 11:nwae124. [PMID: 38778818 PMCID: PMC11110867 DOI: 10.1093/nsr/nwae124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 02/15/2024] [Accepted: 03/11/2024] [Indexed: 05/25/2024] Open
Abstract
The human brain is a complex system, whose activity exhibits flexible and continuous reorganization across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over time with their changes in various brain states remains unclear. Here, we investigate healthy participants taking the serotonergic psychedelic N,N-dimethyltryptamine (DMT) with the Harmonic Decomposition of Spacetime (HADES) framework that can characterize how different harmonic modes defined in space are expressed over time. HADES demonstrates significant decreases in contributions across most low-frequency harmonic modes in the DMT-induced brain state. When normalizing the contributions by condition (DMT and non-DMT), we detect a decrease specifically in the second functional harmonic, which represents the uni- to transmodal functional hierarchy of the brain, supporting the leading hypothesis that functional hierarchy is changed in psychedelics. Moreover, HADES' dynamic spacetime measures of fractional occupancy, life time and latent space provide a precise description of the significant changes of the spacetime hierarchical organization of brain activity in the psychedelic state.
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Affiliation(s)
- Jakub Vohryzek
- Centre for Eudaimonia and Human Flourishing, Linacre College, Department of Psychiatry, University of Oxford, Oxford OX3 9BX, UK
- Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
- Center for Music in the Brain, Aarhus University, Aarhus 8000, Denmark
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona 08005, Spain
| | - Joana Cabral
- Centre for Eudaimonia and Human Flourishing, Linacre College, Department of Psychiatry, University of Oxford, Oxford OX3 9BX, UK
- Life and Health Sciences Research Institute, School of Medicine, University of Minho, Braga 4710-057, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães 4710-057, Portugal
| | - Christopher Timmermann
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, UK
| | - Selen Atasoy
- Centre for Eudaimonia and Human Flourishing, Linacre College, Department of Psychiatry, University of Oxford, Oxford OX3 9BX, UK
- Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
| | - Leor Roseman
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, UK
| | - David J Nutt
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, UK
| | - Robin L Carhart-Harris
- Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, UK
- Departments of Neurology and Psychiatry, University of California San Francisco, San Francisco 94143, USA
| | - Gustavo Deco
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona 08005, Spain
- Institució Catalana de la Recerca i Estudis Avançats (ICREA), Barcelona 08010, Spain
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- School of Psychological Sciences, Monash University, Melbourne, Australia
| | - Morten L Kringelbach
- Centre for Eudaimonia and Human Flourishing, Linacre College, Department of Psychiatry, University of Oxford, Oxford OX3 9BX, UK
- Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK
- Center for Music in the Brain, Aarhus University, Aarhus 8000, Denmark
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Hilal FF, Jeanblanc J, Deschamps C, Naassila M, Pierrefiche O, Ben Hamida S. Epigenetic drugs and psychedelics as emerging therapies for alcohol use disorder: insights from preclinical studies. J Neural Transm (Vienna) 2024; 131:525-561. [PMID: 38554193 DOI: 10.1007/s00702-024-02757-3] [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] [Received: 11/24/2023] [Accepted: 02/22/2024] [Indexed: 04/01/2024]
Abstract
Alcohol use disorder (AUD) is a public health issue that affects millions of people worldwide leading to physical, mental and socio-economic consequences. While current treatments for AUD have provided relief to individuals, their effectiveness on the long term is often limited, leaving a number of affected individuals without sustainable solutions. In this review, we aim to explore two emerging approaches for AUD: psychedelics and epigenetic drugs (i.e., epidrugs). By examining preclinical studies, different animal species and procedures, we delve into the potential benefits of each of these treatments in terms of addictive behaviors (alcohol drinking and seeking, motivation to drink alcohol and prevention of relapse). Because psychedelics and epidrugs may share common and complementary mechanisms of action, there is an exciting opportunity for exploring synergies between these approaches and their parallel effectiveness in treating AUD and the diverse associated psychiatric conditions.
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Affiliation(s)
- Fahd François Hilal
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Jerome Jeanblanc
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Chloé Deschamps
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Mickael Naassila
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France.
| | - Olivier Pierrefiche
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Sami Ben Hamida
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France.
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Avram M, Müller F, Preller KH, Razi A, Rogg H, Korda A, Holze F, Vizeli P, Ley L, Liechti ME, Borgwardt S. Effective Connectivity of Thalamocortical Interactions Following d-Amphetamine, LSD, and MDMA Administration. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:522-532. [PMID: 37532129 DOI: 10.1016/j.bpsc.2023.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 08/04/2023]
Abstract
BACKGROUND While the exploration of serotonergic psychedelics as psychiatric medicines deepens, so does the pressure to better understand how these compounds act on the brain. METHODS We used a double-blind, placebo-controlled, crossover design and administered lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), and d-amphetamine in 25 healthy participants. By using spectral dynamic causal modeling, we mapped substance-induced changes in effective connectivity between the thalamus and different cortex types (unimodal vs. transmodal) derived from a previous study with resting-state functional magnetic resonance imaging data. Due to the distinct pharmacological modes of action of the 3 substances, we were able to investigate specific effects mainly driven by different neurotransmitter systems on thalamocortical and corticothalamic interactions. RESULTS Compared with placebo, all 3 substances increased the effective connectivity from the thalamus to specific unimodal cortices, whereas the influence of these cortices on the thalamus was reduced. These results indicate increased bottom-up and decreased top-down information flow between the thalamus and some unimodal cortices. However, for the amphetamines, we found the opposite effects when examining the effective connectivity with transmodal cortices, including parts of the salience network. Intriguingly, LSD increased the effective connectivity from the thalamus to both unimodal and transmodal cortices, indicating a breach in the hierarchical organization of ongoing brain activity. CONCLUSIONS The results advance our knowledge about the action of psychedelics on the brain and refine current models aiming to explain the underlying neurobiological processes.
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Affiliation(s)
- Mihai Avram
- Translational Psychiatry, Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany; Center of Brain, Behavior, and Metabolism, University of Lübeck, Lübeck, Germany.
| | - Felix Müller
- Department of Psychiatry, University of Basel, Basel, Switzerland
| | - Katrin H Preller
- Pharmaco-Neuroimaging and Cognitive-Emotional Processing, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Zürich, Switzerland
| | - Adeel Razi
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia
| | - Helena Rogg
- Translational Psychiatry, Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany
| | - Alexandra Korda
- Translational Psychiatry, Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany; Center of Brain, Behavior, and Metabolism, University of Lübeck, Lübeck, Germany
| | - Friederike Holze
- Division of Clinical Pharmacology and Toxicology, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Patrick Vizeli
- Division of Clinical Pharmacology and Toxicology, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Laura Ley
- Division of Clinical Pharmacology and Toxicology, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Matthias E Liechti
- Division of Clinical Pharmacology and Toxicology, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Stefan Borgwardt
- Translational Psychiatry, Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany; Center of Brain, Behavior, and Metabolism, University of Lübeck, Lübeck, Germany
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Erritzoe D, Barba T, Spriggs MJ, Rosas FE, Nutt DJ, Carhart-Harris R. Effects of discontinuation of serotonergic antidepressants prior to psilocybin therapy versus escitalopram for major depression. J Psychopharmacol 2024; 38:458-470. [PMID: 38520045 PMCID: PMC11102650 DOI: 10.1177/02698811241237870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/25/2024]
Abstract
BACKGROUND There is growing evidence for the therapeutic effects of the psychedelic drug psilocybin for major depression. However, due to the lack of safety data on combining psilocybin with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) and concerns that there may be a negative interaction on efficacy, participants enrolling in psychedelic trials are usually required to discontinue SNRI/SNRIs prior to enrolling. AIMS Using data from a recent clinical trial examining the comparative efficacy the psychedelic drug psilocybin (P) combined with approximately 20 h of psychological support to a 6-week (daily) course of the SSRI escitalopram plus matched psychological support for major depressive disorder, we explored the effects of discontinuing SSRI/SNRIs prior to study enrolment on study outcomes. METHODS Exploratory post hoc analyses using linear mixed effects model were performed to investigate the discontinuation effect on various validated depression symptom severity scales and well-being. The impact of SSRI/SNRIs discontinuation on the acute psychedelic experience was also explored. RESULTS/OUTCOMES In the psilocybin group, there was a reduced treatment effect on all outcome measures for SSRI/SNRIs discontinuers compared with unmedicated patients at trial entry. However, no effects of discontinuation on measures of the acute psychedelic experience were found. CONCLUSION Discontinuation of SSRI/SNRIs before psilocybin might diminish response to treatment; however, as we did not test SSRI/SNRI continuation in our trial, we cannot infer such causation. Moreover, the exploratory nature of the analyses makes them hypothesis generating, and not confirmatory. A controlled trial of SSRI/SNRI discontinuation versus continuation prior to psilocybin is urgently required.
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Affiliation(s)
- David Erritzoe
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Tommaso Barba
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Meg J Spriggs
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Fernando E Rosas
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Department of Informatics, University of Sussex, Brighton, UK
| | - David J Nutt
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Robin Carhart-Harris
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Departments of Neurology and Psychiatry, University of California San Francisco, San Francisco, CA, USA
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45
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Maia JM, de Oliveira BSA, Branco LGS, Soriano RN. Therapeutic potential of psychedelics: History, advancements, and unexplored frontiers. Prog Neuropsychopharmacol Biol Psychiatry 2024; 131:110951. [PMID: 38307161 DOI: 10.1016/j.pnpbp.2024.110951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/20/2023] [Accepted: 01/18/2024] [Indexed: 02/04/2024]
Abstract
Psychedelics (serotonergic hallucinogens) are psychoactive substances that can alter perception and mood, and affect cognitive functions. These substances activate 5-HT2A receptors and may exert therapeutic effects. Some of the disorders for which psychedelic-assisted therapy have been studied include depression, addiction, anxiety and post-traumatic stress disorder. Despite the increasing number of studies reporting clinical effectiveness, with fewer negative symptoms and, additionally, minimal side effects, questions remain to be explored in the field of psychedelic medicine. Although progress has been achieved, there is still little understanding of the relationship among human brain and the modulation induced by these drugs. The present article aimed to describe, review and highlight the most promising findings in the literature regarding the (putative) therapeutic effects of psychedelics.
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Affiliation(s)
- Juliana Marino Maia
- Department of Medicine, Federal University of Juiz de Fora, Governador Valadares, MG 35032-620, Brazil
| | | | - Luiz G S Branco
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040-904, Brazil; Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040-900, Brazil.
| | - Renato Nery Soriano
- Division of Physiology and Biophysics, Department of Basic Life Sciences, Federal University of Juiz de Fora, Governador Valadares, MG 35020-360, Brazil
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Armstrong M, Castellanos J, Christie D. Chronic pain as an emergent property of a complex system and the potential roles of psychedelic therapies. FRONTIERS IN PAIN RESEARCH 2024; 5:1346053. [PMID: 38706873 PMCID: PMC11066302 DOI: 10.3389/fpain.2024.1346053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 04/02/2024] [Indexed: 05/07/2024] Open
Abstract
Despite research advances and urgent calls by national and global health organizations, clinical outcomes for millions of people suffering with chronic pain remain poor. We suggest bringing the lens of complexity science to this problem, conceptualizing chronic pain as an emergent property of a complex biopsychosocial system. We frame pain-related physiology, neuroscience, developmental psychology, learning, and epigenetics as components and mini-systems that interact together and with changing socioenvironmental conditions, as an overarching complex system that gives rise to the emergent phenomenon of chronic pain. We postulate that the behavior of complex systems may help to explain persistence of chronic pain despite current treatments. From this perspective, chronic pain may benefit from therapies that can be both disruptive and adaptive at higher orders within the complex system. We explore psychedelic-assisted therapies and how these may overlap with and complement mindfulness-based approaches to this end. Both mindfulness and psychedelic therapies have been shown to have transdiagnostic value, due in part to disruptive effects on rigid cognitive, emotional, and behavioral patterns as well their ability to promote neuroplasticity. Psychedelic therapies may hold unique promise for the management of chronic pain.
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Affiliation(s)
- Maya Armstrong
- Department of Family & Community Medicine, University of New Mexico, Albuquerque, NM, United States
| | - Joel Castellanos
- Division of Pain Medicine, Department of Anesthesiology, University of California, San Diego, CA, United States
| | - Devon Christie
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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47
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Sloshower J, Zeifman RJ, Guss J, Krause R, Safi-Aghdam H, Pathania S, Pittman B, D'Souza DC. Psychological flexibility as a mechanism of change in psilocybin-assisted therapy for major depression: results from an exploratory placebo-controlled trial. Sci Rep 2024; 14:8833. [PMID: 38632313 PMCID: PMC11024097 DOI: 10.1038/s41598-024-58318-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 03/27/2024] [Indexed: 04/19/2024] Open
Abstract
Several phase II studies have demonstrated that psilocybin-assisted therapy shows therapeutic potential across a spectrum of neuropsychiatric conditions, including major depressive disorder (MDD). However, the mechanisms underlying its often persisting beneficial effects remain unclear. Observational research suggests that improvements in psychological flexibility may mediate therapeutic effects. However, no psychedelic trials to date have substantiated this finding in a clinical sample. In an exploratory placebo-controlled, within-subject, fixed-order study, individuals with moderate to severe MDD were administered placebo (n = 19) followed by psilocybin (0.3 mg/kg) (n = 15) 4 weeks later. Dosing sessions were embedded within a manualized psychotherapy that incorporated principles of Acceptance and Commitment Therapy. Depression severity, psychological flexibility, mindfulness, and values-congruent living were measured over a 16-weeks study period. Psychological flexibility, several facets of mindfulness, and values-congruent living significantly improved following psilocybin and were maintained through week 16. Additionally, improvements in psychological flexibility and experiential acceptance were strongly associated with reductions in depression severity following psilocybin. These findings support the theoretical premise of integrating psilocybin treatment with psychotherapeutic platforms that target psychological flexibility and add to emerging evidence that increasing psychological flexibility may be an important putative mechanism of change in psilocybin-assisted therapy for MDD and potentially, other mental health conditions.
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Affiliation(s)
- Jordan Sloshower
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA.
- West Rock Wellness PLLC, New Haven, CT, USA.
| | - Richard J Zeifman
- NYU Langone Center for Psychedelic Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Jeffrey Guss
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY, USA
| | - Robert Krause
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Yale School of Nursing, New Haven, CT, USA
- Centered PLLC, New Haven, CT, USA
| | - Hamideh Safi-Aghdam
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Surbhi Pathania
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
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48
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Tap SC. The potential of 5-methoxy-N,N-dimethyltryptamine in the treatment of alcohol use disorder: A first look at therapeutic mechanisms of action. Addict Biol 2024; 29:e13386. [PMID: 38600715 PMCID: PMC11007263 DOI: 10.1111/adb.13386] [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] [Received: 09/27/2023] [Revised: 12/24/2023] [Accepted: 02/13/2024] [Indexed: 04/12/2024]
Abstract
Alcohol use disorder (AUD) remains one of the most prevalent psychiatric disorders worldwide with high economic costs. Current treatment options show modest efficacy and relapse rates are high. Furthermore, there are increases in the treatment gap and few new medications have been approved in the past 20 years. Recently, psychedelic-assisted therapy with psilocybin and lysergic acid diethylamide has garnered significant attention in the treatment of AUD. Yet, they require significant amounts of therapist input due to prolonged subjective effects (~4-12 h) leading to high costs and impeding implementation. Accordingly, there is an increasing interest in the rapid and short-acting psychedelic 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). This paper offers a first look at potential therapeutic mechanisms for AUD by reviewing the current literature on 5-MeO-DMT. Primarily, 5-MeO-DMT is able to induce mystical experiences and ego-dissolution together with increases in psychological flexibility and mindfulness. This could decrease AUD symptoms through the alleviation of psychiatric mood-related comorbidities consistent with the negative reinforcement and self-medication paradigms. In addition, preliminary evidence indicates that 5-MeO-DMT modulates neural oscillations that might subserve ego-dissolution (increases in gamma), psychological flexibility and mindfulness (increases in theta), and the reorganization of executive control networks (increases in coherence across frequencies) that could improve emotion regulation and inhibition. Finally, animal studies show that 5-MeO-DMT is characterized by neuroplasticity, anti-inflammation, 5-HT2A receptor agonism, and downregulation of metabotropic glutamate receptor 5 with clinical implications for AUD and psychiatric mood-related comorbidities. The paper concludes with several recommendations for future research to establish the purported therapeutic mechanisms of action.
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Affiliation(s)
- Stephan C. Tap
- Department of PsychiatryGroningen University Medical CenterGroningenThe Netherlands
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49
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Tolle HM, Farah JC, Mallaroni P, Mason NL, Ramaekers JG, Amico E. The unique neural signature of your trip: Functional connectome fingerprints of subjective psilocybin experience. Netw Neurosci 2024; 8:203-225. [PMID: 38562294 PMCID: PMC10898784 DOI: 10.1162/netn_a_00349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/23/2023] [Indexed: 04/04/2024] Open
Abstract
The emerging neuroscientific frontier of brain fingerprinting has recently established that human functional connectomes (FCs) exhibit fingerprint-like idiosyncratic features, which map onto heterogeneously distributed behavioral traits. Here, we harness brain-fingerprinting tools to extract FC features that predict subjective drug experience induced by the psychedelic psilocybin. Specifically, in neuroimaging data of healthy volunteers under the acute influence of psilocybin or a placebo, we show that, post psilocybin administration, FCs become more idiosyncratic owing to greater intersubject dissimilarity. Moreover, whereas in placebo subjects idiosyncratic features are primarily found in the frontoparietal network, in psilocybin subjects they concentrate in the default mode network (DMN). Crucially, isolating the latter revealed an FC pattern that predicts subjective psilocybin experience and is characterized by reduced within-DMN and DMN-limbic connectivity, as well as increased connectivity between the DMN and attentional systems. Overall, these results contribute to bridging the gap between psilocybin-mediated effects on brain and behavior, while demonstrating the value of a brain-fingerprinting approach to pharmacological neuroimaging.
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Affiliation(s)
- Hanna M. Tolle
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Juan Carlos Farah
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Natasha L. Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Johannes G. Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Enrico Amico
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
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50
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Juliani A, Safron A, Kanai R. Deep CANALs: a deep learning approach to refining the canalization theory of psychopathology. Neurosci Conscious 2024; 2024:niae005. [PMID: 38533457 PMCID: PMC10965250 DOI: 10.1093/nc/niae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 03/28/2024] Open
Abstract
Psychedelic therapy has seen a resurgence of interest in the last decade, with promising clinical outcomes for the treatment of a variety of psychopathologies. In response to this success, several theoretical models have been proposed to account for the positive therapeutic effects of psychedelics. One of the more prominent models is "RElaxed Beliefs Under pSychedelics," which proposes that psychedelics act therapeutically by relaxing the strength of maladaptive high-level beliefs encoded in the brain. The more recent "CANAL" model of psychopathology builds on the explanatory framework of RElaxed Beliefs Under pSychedelics by proposing that canalization (the development of overly rigid belief landscapes) may be a primary factor in psychopathology. Here, we make use of learning theory in deep neural networks to develop a series of refinements to the original CANAL model. Our primary theoretical contribution is to disambiguate two separate optimization landscapes underlying belief representation in the brain and describe the unique pathologies which can arise from the canalization of each. Along each dimension, we identify pathologies of either too much or too little canalization, implying that the construct of canalization does not have a simple linear correlation with the presentation of psychopathology. In this expanded paradigm, we demonstrate the ability to make novel predictions regarding what aspects of psychopathology may be amenable to psychedelic therapy, as well as what forms of psychedelic therapy may ultimately be most beneficial for a given individual.
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Affiliation(s)
- Arthur Juliani
- Microsoft Research , Microsoft, 300 Lafayette St, New York, NY 10012, USA
| | - Adam Safron
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, 600 N Wolfe St, Baltimore, MD 21205, USA
| | - Ryota Kanai
- Neurotechnology R & D Unit, Araya Inc, 6F Sanpo Sakuma Building, 1-11 Kandasakumacho, Chiyoda-ku, Tokyo 101-0025, Japan
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