51
|
Sanz C, Pallavicini C, Carrillo F, Zamberlan F, Sigman M, Mota N, Copelli M, Ribeiro S, Nutt D, Carhart-Harris R, Tagliazucchi E. The entropic tongue: Disorganization of natural language under LSD. Conscious Cogn 2021; 87:103070. [PMID: 33307427 DOI: 10.1016/j.concog.2020.103070] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 09/10/2020] [Accepted: 11/28/2020] [Indexed: 02/09/2023]
Abstract
Serotonergic psychedelics have been suggested to mirror certain aspects of psychosis, and, more generally, elicit a state of consciousness underpinned by increased entropy of on-going neural activity. We investigated the hypothesis that language produced under the effects of lysergic acid diethylamide (LSD) should exhibit increased entropy and reduced semantic coherence. Computational analysis of interviews conducted at two different time points after 75 μg of intravenous LSD verified this prediction. Non-semantic analysis of speech organization revealed increased verbosity and a reduced lexicon, changes that are more similar to those observed during manic psychoses than in schizophrenia, which was confirmed by direct comparison with reference samples. Importantly, features related to language organization allowed machine learning classifiers to identify speech under LSD with accuracy comparable to that obtained by examining semantic content. These results constitute a quantitative and objective characterization of disorganized natural speech as a landmark feature of the psychedelic state.
Collapse
Affiliation(s)
- Camila Sanz
- Departamento de Física, Universidad de Buenos Aires and Instituto de Física de Buenos Aires (IFIBA - CONICET), Pabellón I, Ciudad Universitaria (1428), CABA, Buenos Aires, Argentina
| | - Carla Pallavicini
- Departamento de Física, Universidad de Buenos Aires and Instituto de Física de Buenos Aires (IFIBA - CONICET), Pabellón I, Ciudad Universitaria (1428), CABA, Buenos Aires, Argentina; Fundación para la lucha contra las enfermedades neurológicas de la infancia (FLENI), Montañeses 2325, C1428 CABA, Buenos Aires, Argentina
| | - Facundo Carrillo
- Applied Artificial Intelligence Lab (ICC-CONICET), Pabellón I, Ciudad Universitaria (1428), CABA, Buenos Aires, Argentina
| | - Federico Zamberlan
- Departamento de Física, Universidad de Buenos Aires and Instituto de Física de Buenos Aires (IFIBA - CONICET), Pabellón I, Ciudad Universitaria (1428), CABA, Buenos Aires, Argentina
| | - Mariano Sigman
- Universidad Torcuato Di Tella, Juan Pablo Sáenz Valiente 1010, C1428BIJ CABA, Buenos Aires, Argentina
| | - Natalia Mota
- Brain Institute, Federal University of Rio Grande do Norte, Av. Sen. Salgado Filho, 3000 Candelária, Natal, Brazil
| | - Mauro Copelli
- Physics Department, Federal University of Pernambuco, Av. Prof. Moraes Rego 1235, Cidade Universitária, Recife, PE 50670-901, Brazil
| | - Sidarta Ribeiro
- Brain Institute, Federal University of Rio Grande do Norte, Av. Sen. Salgado Filho, 3000 Candelária, Natal, Brazil
| | - David Nutt
- Centre for Psychedelic Research, Department of Medicine, Imperial College London, Kensington, London SW7 2DD, United Kingdom
| | - Robin Carhart-Harris
- Centre for Psychedelic Research, Department of Medicine, Imperial College London, Kensington, London SW7 2DD, United Kingdom
| | - Enzo Tagliazucchi
- Departamento de Física, Universidad de Buenos Aires and Instituto de Física de Buenos Aires (IFIBA - CONICET), Pabellón I, Ciudad Universitaria (1428), CABA, Buenos Aires, Argentina.
| |
Collapse
|
52
|
Herzog R, Mediano PAM, Rosas FE, Carhart-Harris R, Perl YS, Tagliazucchi E, Cofre R. A mechanistic model of the neural entropy increase elicited by psychedelic drugs. Sci Rep 2020; 10:17725. [PMID: 33082424 PMCID: PMC7575594 DOI: 10.1038/s41598-020-74060-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 09/24/2020] [Indexed: 12/27/2022] Open
Abstract
Psychedelic drugs, including lysergic acid diethylamide and other agonists of the serotonin 2A receptor (5HT2A-R), induce drastic changes in subjective experience, and provide a unique opportunity to study the neurobiological basis of consciousness. One of the most notable neurophysiological signatures of psychedelics, increased entropy in spontaneous neural activity, is thought to be of relevance to the psychedelic experience, mediating both acute alterations in consciousness and long-term effects. However, no clear mechanistic explanation for this entropy increase has been put forward so far. We sought to do this here by building upon a recent whole-brain model of serotonergic neuromodulation, to study the entropic effects of 5HT2A-R activation. Our results reproduce the overall entropy increase observed in previous experiments in vivo, providing the first model-based explanation for this phenomenon. We also found that entropy changes were not uniform across the brain: entropy increased in some regions and decreased in others, suggesting a topographical reconfiguration mediated by 5HT2A-R activation. Interestingly, at the whole-brain level, this reconfiguration was not well explained by 5HT2A-R density, but related closely to the topological properties of the brain's anatomical connectivity. These results help us understand the mechanisms underlying the psychedelic state and, more generally, the pharmacological modulation of whole-brain activity.
Collapse
Affiliation(s)
- Rubén Herzog
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Pje Harrington 287, 2360103, Valparaiso, Chile.
| | - Pedro A M Mediano
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
| | - Fernando E Rosas
- Department of Brain Science, Centre for Psychedelic Research, Imperial College London, London, SW7 2DD, UK.,Data Science Institute, Imperial College London, London, SW7 2AZ, UK.,Centre for Complexity Science, Imperial College London, London, SW7 2AZ, UK
| | - Robin Carhart-Harris
- Department of Brain Science, Centre for Psychedelic Research, Imperial College London, London, SW7 2DD, UK
| | - Yonatan Sanz Perl
- Buenos Aires Physics Institute and Physics Department, University of Buenos Aires, Buenos Aires, Argentina.,National Scientific and Technical Research Council, Buenos Aires, Argentina.,Universidad de San Andres, Buenos Aires, Argentina
| | - Enzo Tagliazucchi
- Buenos Aires Physics Institute and Physics Department, University of Buenos Aires, Buenos Aires, Argentina.,National Scientific and Technical Research Council, Buenos Aires, Argentina
| | - Rodrigo Cofre
- CIMFAV-Ingemat, Facultad de Ingeniería, Universidad de Valparaíso, Valparaiso, Chile
| |
Collapse
|
53
|
Altman BR, Mian MN, Earleywine M. The Novelty of Ayahuasca Scale and the prediction of intentions to use. JOURNAL OF PSYCHEDELIC STUDIES 2020. [DOI: 10.1556/2054.2020.00117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
AbstractObjectiveGiven the growing popularity of ayahuasca and other hallucinogens, we sought to identify related expectancies and their role in why people might use this psychoactive brew rather than classic hallucinogens like LSD or psilocybin.MethodExperienced users (N = 139) completed an online survey about their use of hallucinogens (including ayahuasca), how their ayahuasca experiences differed from those with other hallucinogens, as well as their intentions to use hallucinogens (including ayahuasca) in the future.ResultsParticipants expected ayahuasca effects to differ meaningfully from the effects of other hallucinogens in multiple domains. Expected differences involved positive connections to nature (and other people), dramatic (or terrifying) thoughts, high variability of effects, and physical reactions. Intentions to use ayahuasca in the future increased as expectancies for positive connections increased, but decreased as physical reactions increased. One version of the full Novelty of Ayahuasca scale significantly covaried with the likelihood of using ayahuasca over other hallucinogens in the future, while another version did not. This result calls for further work examining how users perceive certain ayahuasca-induced effects.ConclusionsThese findings reveal that expectancies for ayahuasca differ from those for other hallucinogens, and impact an individual's willingness to try the substance again. Understanding these differences might help those who are interested in the therapeutic potential of hallucinogens decide among those available. Future studies might examine how these expectancies predict intentions to use ayahuasca (and other hallucinogens) longitudinally. Comparable approaches could also identify unique expectancies for other hallucinogens to see if those predict a preference for one over others.
Collapse
Affiliation(s)
- Brianna R. Altman
- Department of Psychology, University at Albany, State University of New York, Albany, NY, USA
| | - M. N. Mian
- Department of Psychology, University at Albany, State University of New York, Albany, NY, USA
| | - M. Earleywine
- Department of Psychology, University at Albany, State University of New York, Albany, NY, USA
| |
Collapse
|
54
|
Psychedelics and psychological flexibility – Results of a prospective web-survey using the Acceptance and Action Questionnaire II. JOURNAL OF CONTEXTUAL BEHAVIORAL SCIENCE 2020. [DOI: 10.1016/j.jcbs.2020.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
55
|
Wolff M, Evens R, Mertens LJ, Koslowski M, Betzler F, Gründer G, Jungaberle H. Learning to Let Go: A Cognitive-Behavioral Model of How Psychedelic Therapy Promotes Acceptance. Front Psychiatry 2020; 11:5. [PMID: 32153433 PMCID: PMC7046795 DOI: 10.3389/fpsyt.2020.00005] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/03/2020] [Indexed: 12/24/2022] Open
Abstract
The efficacy of psychedelic-assisted therapies for mental disorders has been attributed to the lasting change from experiential avoidance to acceptance that these treatments appear to facilitate. This article presents a conceptual model that specifies potential psychological mechanisms underlying such change, and that shows substantial parallels between psychedelic therapy and cognitive behavioral therapy: We propose that in the carefully controlled context of psychedelic therapy as applied in contemporary clinical research, psychedelic-induced belief relaxation can increase motivation for acceptance via operant conditioning, thus engendering episodes of relatively avoidance-free exposure to greatly intensified private events. Under these unique learning conditions, relaxed avoidance-related beliefs can be exposed to corrective information and become revised accordingly, which may explain long-term increases in acceptance and corresponding reductions in psychopathology. Open research questions and implications for clinical practice are discussed.
Collapse
Affiliation(s)
- Max Wolff
- Faculty of Psychology, Technische Universität Dresden, Dresden, Germany
- Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
- MIND Foundation, Berlin, Germany
| | - Ricarda Evens
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Lea J. Mertens
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Michael Koslowski
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Felix Betzler
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Gerhard Gründer
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | | |
Collapse
|
56
|
Moreton SG, Szalla L, Menzies RE, Arena AF. Embedding existential psychology within psychedelic science: reduced death anxiety as a mediator of the therapeutic effects of psychedelics. Psychopharmacology (Berl) 2020; 237:21-32. [PMID: 31784805 DOI: 10.1007/s00213-019-05391-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 11/04/2019] [Indexed: 12/19/2022]
Abstract
Psychedelic therapies can engender enduring improvements in psychological well-being. However, relatively little is known about the psychological mechanisms through which the salutary effects of psychedelics emerge. Through integrating extant research on psychedelics with contemporary existential psychology, we present a novel hypothesis that reduced death anxiety may be a key mechanism underpinning the therapeutic effects of psychedelics. In developing this hypothesis, we also provide a complementary review of mechanisms through which psychedelics may reduce death anxiety. We conclude that an awareness of the role of death anxiety in psychopathology has the potential to guide future research into psychedelic therapies.
Collapse
Affiliation(s)
- Sam G Moreton
- School of Psychology, University of Wollongong, Wollongong, NSW, 2522, Australia.
| | - Luke Szalla
- School of Psychology, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Rachel E Menzies
- School of Psychology, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Andrew F Arena
- School of Psychology, University of Sydney, Camperdown, NSW, 2006, Australia
| |
Collapse
|
57
|
Abstract
Sigmund Freud, the founder of psychoanalysis, is predominantly known for his conception of the id, ego and super-ego, representing a part of his meta-psychology of the psychic apparatus. Nowadays, with the advancements in technology and science, his meta-psychological structural model of the psyche might be either confirmed or denied by comparing the account of the psychic apparatus of the classical psychoanalysis to the newest findings in neuropsychology and cognitive neuroscience. Indeed, the founded interdisciplinary project of neuro-psychoanalysis strives to answer such questions. In this article, the current thinking on the discussions around Freudian ego and its possible brain correlates is presented. In 2010, Robin Carhart-Harris and Karl Friston introduced a neuro-psychoanalytic account of the psychic apparatus, where the ego correlated with a large-scale brain network called the default-mode network. In the end of this paper, an original theoretical hypothesis is offered, supplemented with review of the literature, namely that the central-executive network and the salience network are viewed as the true representatives of Freudian ego. The offered hypothesis criticizes Carhart-Harris and Friston’s postulating of the default-mode network as being the brain representative of Freudian ego.
Collapse
|
58
|
Fischman LG. Seeing without self: Discovering new meaning with psychedelic-assisted psychotherapy. ACTA ACUST UNITED AC 2019. [DOI: 10.1080/15294145.2019.1689528] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Lawrence G. Fischman
- Department of Psychiatry, Tufts University School of Medicine-Maine Medical Center, Portland, ME, USA
| |
Collapse
|
59
|
de la Fuente Revenga M, Shin JM, Vohra HZ, Hideshima KS, Schneck M, Poklis JL, González-Maeso J. Fully automated head-twitch detection system for the study of 5-HT 2A receptor pharmacology in vivo. Sci Rep 2019; 9:14247. [PMID: 31582824 PMCID: PMC6776537 DOI: 10.1038/s41598-019-49913-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/30/2019] [Indexed: 01/29/2023] Open
Abstract
Head-twitch behavior (HTR) is the behavioral signature of psychedelic drugs upon stimulation of the serotonin 5-HT2A receptor (5-HT2AR) in rodents. Following the previous report of a semi-automated detection of HTR based on the dynamics of mouse's head movement, here we present a system for the identification of individual HTR events in a fully automated fashion. The validity of this fully automated HTR detection system was tested with the psychedelic drug DOI in 5-HT2AR-KO mice, and via evaluation of potential sources of false-positive and false-negative HTR events. The increased throughput in data processing achieved via automation afforded the possibility of conducting otherwise time consuming HTR time-course studies. To further assess the versatility of our system, we also explored the pharmacological interactions between 5-HT2AR and the metabotropic glutamate receptor 2 (mGluR2). Our data demonstrate the potentiation effect of the mGluR2/3 antagonist LY341495 on DOI-induced HTR, as well as the HTR-blocking effect of the mGluR2/3 agonist and antipsychotic drug in development LY404039. This fully automated system can contribute to speed up our understanding of 5-HT2AR's pharmacology and its characteristic behavioral outputs in rodents.
Collapse
Affiliation(s)
- Mario de la Fuente Revenga
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Jong M Shin
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Hiba Z Vohra
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Kelsey S Hideshima
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Matthew Schneck
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.,Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, 23220, USA
| | - Justin L Poklis
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
| |
Collapse
|
60
|
Aday JS, Bloesch EK, Davoli CC. Can Psychedelic Drugs Attenuate Age-Related Changes in Cognition and Affect? JOURNAL OF COGNITIVE ENHANCEMENT 2019. [DOI: 10.1007/s41465-019-00151-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
61
|
Volgin AD, Yakovlev OA, Demin KA, Alekseeva PA, Kyzar EJ, Collins C, Nichols DE, Kalueff AV. Understanding Central Nervous System Effects of Deliriant Hallucinogenic Drugs through Experimental Animal Models. ACS Chem Neurosci 2019; 10:143-154. [PMID: 30252437 DOI: 10.1021/acschemneuro.8b00433] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Hallucinogenic drugs potently alter human behavior and have a millennia-long history of use for medicinal and religious purposes. Interest is rapidly growing in their potential as CNS modulators and therapeutic agents for brain conditions. Antimuscarinic cholinergic drugs, such as atropine and scopolamine, induce characteristic hyperactivity and dream-like hallucinations and form a separate group of hallucinogens known as "deliriants". Although atropine and scopolamine are relatively well-studied drugs in cholinergic physiology, deliriants represent the least-studied class of hallucinogens in terms of their behavioral and neurological phenotypes. As such, novel approaches and new model organisms are needed to investigate the CNS effects of these compounds. Here, we comprehensively evaluate the preclinical effects of deliriant hallucinogens in various animal models, their mechanisms of action, and potential interplay with other signaling pathways. We also parallel experimental and clinical findings on deliriant agents and outline future directions of translational research in this field.
Collapse
Affiliation(s)
- Andrey D. Volgin
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
- Almazov National Medical Research Centre, St. Petersburg 197341, Russia
- Military Medical Academy, St. Petersburg 194044, Russia
| | - Oleg A. Yakovlev
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
- Almazov National Medical Research Centre, St. Petersburg 197341, Russia
- Military Medical Academy, St. Petersburg 194044, Russia
| | | | | | - Evan J. Kyzar
- College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, United States
- The International Zebrafish Neuroscience Research Consortium (ZNRC), New Orleans, Louisiana 70458, United States
| | - Christopher Collins
- The International Zebrafish Neuroscience Research Consortium (ZNRC), New Orleans, Louisiana 70458, United States
| | - David E. Nichols
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Allan V. Kalueff
- School of Pharmacy, Southwest University, Chongqing 400716, China
- Scientific Research Institute of Physiology and Basic Medicine, Novosibirsk 630117, Russiai
- Ural Federal University, Ekaterinburg 620075, Russia
- ZENEREI Research Center, Slidell, Louisiana 70458, United States
- Laboratory of Biological Psychiatry, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
| |
Collapse
|
62
|
Atasoy S, Vohryzek J, Deco G, Carhart-Harris RL, Kringelbach ML. Common neural signatures of psychedelics: Frequency-specific energy changes and repertoire expansion revealed using connectome-harmonic decomposition. PROGRESS IN BRAIN RESEARCH 2018; 242:97-120. [PMID: 30471684 DOI: 10.1016/bs.pbr.2018.08.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The search for the universal laws of human brain function is still on-going but progress is being made. Here we describe the novel concepts of connectome harmonics and connectome-harmonic decomposition, which can be used to characterize the brain activity associated with any mental state. We use this new frequency-specific language to describe the brain activity elicited by psilocybin and LSD and find remarkably similar effects in terms of increases in total energy and power, as well as frequency-specific energy changes and repertoire expansion. In addition, we find enhanced signatures of criticality suggesting that the brain dynamics tune toward criticality in both psychedelic elicited states. Overall, our findings provide new evidence for the remarkable ability of psychedelics to change the spatiotemporal dynamics of the human brain.
Collapse
Affiliation(s)
- Selen Atasoy
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Center for Music in the Brain, Aarhus University, Aarhus, Denmark
| | - Jakub Vohryzek
- Department of Psychiatry, 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), Barcelona, 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
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Center for Music in the Brain, Aarhus University, Aarhus, Denmark.
| |
Collapse
|
63
|
Abstract
Archeological studies in the United States, Mexico, and Peru suggest that mescaline, as a cactus constituent, has been used for more than 6000 years. Although it is a widespread cactus alkaloid, it is present in high concentrations in few species, notably the North American peyote ( Lophophora williamsii) and the South American wachuma ( Trichocereus pachanoi, T. peruvianus, and T. bridgesii). Spanish 16th century chroniclers considered these cacti "diabolic", leading to their prohibition, but their use persisted to our days and has been spreading for the last 150 years. In the late 1800s, peyote attracted scientific attention; mescaline was isolated, and its role in the psychedelic effects of peyote tops or "mescal buttons" was demonstrated. Its structure was established by synthesis in 1929, and alternative routes were developed, providing larger amounts for pharmacological and biosynthetic research. Although its effects are attributed mainly to its action as a 5-HT2A serotonin receptor agonist, mescaline binds in a similar concentration range to 5-HT1A and α2A receptors. It is largely excreted unchanged in human urine, and its metabolic products are apparently unrelated to its psychedelic properties. Its low potency is probably responsible for its relative neglect by recreational substance users, as the successful search for structure-activity relationships in the hallucinogen field focused largely on finding more potent analogues. Renewed interest in the possible therapeutic applications of psychedelic drugs may hopefully lead to novel insights regarding the commonalities and differences between the actions of individual classic hallucinogens.
Collapse
Affiliation(s)
- Bruce K. Cassels
- Chemobiodynamics Laboratory, Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7900003, Chile
| | - Patricio Sáez-Briones
- Laboratory of Neuropharmacology and Behavior, School of Medicine, Faculty of Medical Sciences, Universidad de Santiago de Chile, Santiago 9170022, Chile
| |
Collapse
|
64
|
Millière R, Carhart-Harris RL, Roseman L, Trautwein FM, Berkovich-Ohana A. Psychedelics, Meditation, and Self-Consciousness. Front Psychol 2018; 9:1475. [PMID: 30245648 PMCID: PMC6137697 DOI: 10.3389/fpsyg.2018.01475] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/26/2018] [Indexed: 12/22/2022] Open
Abstract
In recent years, the scientific study of meditation and psychedelic drugs has seen remarkable developments. The increased focus on meditation in cognitive neuroscience has led to a cross-cultural classification of standard meditation styles validated by functional and structural neuroanatomical data. Meanwhile, the renaissance of psychedelic research has shed light on the neurophysiology of altered states of consciousness induced by classical psychedelics, such as psilocybin and LSD, whose effects are mainly mediated by agonism of serotonin receptors. Few attempts have been made at bridging these two domains of inquiry, despite intriguing evidence of overlap between the phenomenology and neurophysiology of meditation practice and psychedelic states. In particular, many contemplative traditions explicitly aim at dissolving the sense of self by eliciting altered states of consciousness through meditation, while classical psychedelics are known to produce significant disruptions of self-consciousness, a phenomenon known as drug-induced ego dissolution. In this article, we discuss available evidence regarding convergences and differences between phenomenological and neurophysiological data on meditation practice and psychedelic drug-induced states, with a particular emphasis on alterations of self-experience. While both meditation and psychedelics may disrupt self-consciousness and underlying neural processes, we emphasize that neither meditation nor psychedelic states can be conceived as simple, uniform categories. Moreover, we suggest that there are important phenomenological differences even between conscious states described as experiences of self-loss. As a result, we propose that self-consciousness may be best construed as a multidimensional construct, and that "self-loss," far from being an unequivocal phenomenon, can take several forms. Indeed, various aspects of self-consciousness, including narrative aspects linked to autobiographical memory, self-related thoughts and mental time travel, and embodied aspects rooted in multisensory processes, may be differently affected by psychedelics and meditation practices. Finally, we consider long-term outcomes of experiences of self-loss induced by meditation and psychedelics on individual traits and prosocial behavior. We call for caution regarding the problematic conflation of temporary states of self-loss with "selflessness" as a behavioral or social trait, although there is preliminary evidence that correlations between short-term experiences of self-loss and long-term trait alterations may exist.
Collapse
Affiliation(s)
- Raphaël Millière
- Faculty of Philosophy, University of Oxford, Oxford, United Kingdom
| | - Robin L. Carhart-Harris
- Psychedelic Research Group, Psychopharmacology Unit, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Leor Roseman
- Psychedelic Research Group, Psychopharmacology Unit, Department of Medicine, Centre for Psychiatry, Imperial College London, London, United Kingdom
| | - Fynn-Mathis Trautwein
- Department of Social Neuroscience, Max-Planck-Institut für Kognitions- und Neurowissenschaften, Leipzig, Germany
| | - Aviva Berkovich-Ohana
- Faculty of Education, Edmond Safra Brain Research Center, University of Haifa, Haifa, Israel
| |
Collapse
|
65
|
Garcia-Romeu A, Richards WA. Current perspectives on psychedelic therapy: use of serotonergic hallucinogens in clinical interventions. Int Rev Psychiatry 2018; 30:291-316. [PMID: 30422079 DOI: 10.1080/09540261.2018.1486289] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Humans have used serotonergic hallucinogens (i.e. psychedelics) for spiritual, ceremonial, and recreational purposes for thousands of years, but their administration as part of a structured therapeutic intervention is still a relatively novel practice within Western medical and psychological frameworks. In the mid-20th century, considerable advances were made in developing therapeutic approaches integrating administration of low (psycholytic) and high (psychedelic) doses of serotonergic hallucinogens for treatment of a variety of conditions, often incorporating psychoanalytic concepts prevalent at that time. This work contributed seminal insights regarding how these substances may be employed with efficacy and safety in targeted therapeutic interventions, including the importance of optimizing set (frame of mind) and setting (therapeutic environment). More recently, clinical and pharmacological research has revisited the effects and therapeutic potential of psychedelics utilizing a variety of approaches. The current article provides an overview of past and present models of psychedelic therapy, and discusses important considerations for future interventions incorporating the use of psychedelics in research and clinical practice.
Collapse
Affiliation(s)
- Albert Garcia-Romeu
- a Department of Psychiatry & Behavioral Sciences , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - William A Richards
- a Department of Psychiatry & Behavioral Sciences , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| |
Collapse
|
66
|
Michaels TI, Purdon J, Collins A, Williams MT. Inclusion of people of color in psychedelic-assisted psychotherapy: a review of the literature. BMC Psychiatry 2018; 18:245. [PMID: 30064392 PMCID: PMC6069717 DOI: 10.1186/s12888-018-1824-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 07/23/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Despite renewed interest in studying the safety and efficacy of psychedelic-assisted psychotherapy for the treatment of psychological disorders, the enrollment of racially diverse participants and the unique presentation of psychopathology in this population has not been a focus of this potentially ground-breaking area of research. In 1993, the United States National Institutes of Health issued a mandate that funded research must include participants of color and proposals must include methods for achieving diverse samples. METHODS A methodological search of psychedelic studies from 1993 to 2017 was conducted to evaluate ethnoracial differences in inclusion and effective methods of recruiting peopple of color. RESULTS Of the 18 studies that met full criteria (n = 282 participants), 82.3% of the participants were non-Hispanic White, 2.5% were African-American, 2.1% were of Latino origin, 1.8% were of Asian origin, 4.6% were of indigenous origin, 4.6% were of mixed race, 1.8% identified their race as "other," and the ethnicity of 8.2% of participants was unknown. There were no significant differences in recruitment methodologies between those studies that had higher (> 20%) rates of inclusion. CONCLUSIONS As minorities are greatly underrepresented in psychedelic medicine studies, reported treatment outcomes may not generalize to all ethnic and cultural groups. Inclusion of minorities in futures studies and improved recruitment strategies are necessary to better understand the efficacy of psychedelic-assisted psychotherapy in people of color and provide all with equal opportunities for involvement in this potentially promising treatment paradigm.
Collapse
Affiliation(s)
- Timothy I. Michaels
- 0000 0001 0860 4915grid.63054.34Department of Psychological Sciences, University of Connecticut, Bousfield Psychology Building, 406 Babbidge Road, Unit 1020, Storrs, CT 06269 USA
| | - Jennifer Purdon
- 0000 0001 0860 4915grid.63054.34Department of Psychological Sciences, University of Connecticut, Bousfield Psychology Building, 406 Babbidge Road, Unit 1020, Storrs, CT 06269 USA ,0000000419370394grid.208078.5Department of Psychiatry, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030 USA
| | - Alexis Collins
- 0000 0001 0860 4915grid.63054.34Department of Psychological Sciences, University of Connecticut, Bousfield Psychology Building, 406 Babbidge Road, Unit 1020, Storrs, CT 06269 USA
| | - Monnica T. Williams
- 0000 0001 0860 4915grid.63054.34Department of Psychological Sciences, University of Connecticut, Bousfield Psychology Building, 406 Babbidge Road, Unit 1020, Storrs, CT 06269 USA ,0000000419370394grid.208078.5Department of Psychiatry, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030 USA
| |
Collapse
|