101
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Long-term effects of psychedelic drugs: A systematic review. Neurosci Biobehav Rev 2020; 113:179-189. [PMID: 32194129 DOI: 10.1016/j.neubiorev.2020.03.017] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 03/14/2020] [Accepted: 03/15/2020] [Indexed: 12/20/2022]
Abstract
Research into the basic effects and therapeutic applications of psychedelic drugs has grown considerably in recent years. Yet, pressing questions remain regarding the substances' lasting effects. Although individual studies have begun monitoring sustained changes, no study to-date has synthesized this information. Therefore, this systematic review aims to fill this important gap in the literature by synthesizing results from 34 contemporary experimental studies which included classic psychedelics, human subjects, and follow-up latencies of at least two weeks. The bulk of this work was published in the last five years, with psilocybin being the most frequently administered drug. Enduring changes in personality/attitudes, depression, spirituality, anxiety, wellbeing, substance misuse, meditative practices, and mindfulness were documented. Mystical experiences, connectedness, emotional breakthrough, and increased neural entropy were related to these long-term changes in psychological functioning. Finally, with proper screening, preparation, supervision, and integration, limited aversive side effects were noted by study participants. Future researchers should focus on including larger and more diverse samples, lengthier longitudinal designs, stronger control conditions, and standardized dosages.
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102
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Affiliation(s)
- Thomas Metzinger
- Philosophisches Seminar, Johannes Gutenberg-Universität Mainz, Mainz, Germany
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103
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Lewis CR, Preller KH, Braden BB, Riecken C, Vollenweider FX. Rostral Anterior Cingulate Thickness Predicts the Emotional Psilocybin Experience. Biomedicines 2020; 8:biomedicines8020034. [PMID: 32085521 PMCID: PMC7168190 DOI: 10.3390/biomedicines8020034] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 01/02/2023] Open
Abstract
Psilocybin is the psychoactive compound of mushrooms in the psilocybe species. Psilocybin directly affects a number of serotonin receptors, with highest affinity for the serotonin 2A receptor (5HT-2Ar). Generally, the effects of psilocybin, and its active metabolite psilocin, are well established and include a range of cognitive, emotional, and perceptual perturbations. Despite the generality of these effects, there is a high degree of inter-individual variability in subjective psilocybin experiences that are not well understood. Others have shown brain morphology metrics derived from magnetic resonance imaging (MRI) can predict individual drug response. Due to high expression of serotonin 2A receptors (5HT-2Ar) in the cingulate cortex, and its prior associations with psilocybin, we investigate if cortical thickness of this structure predicts the psilocybin experience in healthy adults. We hypothesized that greater cingulate thickness would predict higher subjective ratings in sub-scales of the Five-Dimensional Altered State of Consciousness (5D-ASC) with high emotionality in healthy participants (n = 55) who received oral psilocybin (either low dose: 0.160 mg/kg or high dose: 0.215 mg/kg). After controlling for sex, age, and using false discovery rate (FDR) correction, we found the rostral anterior cingulate predicted all four emotional sub-scales, whereas the caudal and posterior cingulate did not. How classic psychedelic compounds induce such large inter-individual variability in subjective states has been a long-standing question in serotonergic research. These results extend the traditional set and setting hypothesis of the psychedelic experience to include brain structure metrics.
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Affiliation(s)
- Candace R. Lewis
- Translational Genomics Research Institute, Neurogenomics Division, Phoenix, AZ 85004, USA
- Neuropsychopharamacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry, Zurich 8032, Switzerland; (K.H.P.); (F.X.V.)
- Correspondence: ; Tel.: +1-602-343-8400
| | - Katrin H. Preller
- Neuropsychopharamacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry, Zurich 8032, Switzerland; (K.H.P.); (F.X.V.)
| | - B. Blair Braden
- Arizona State University, College of Health Solutions, Tempe 85281, AZ 85004, USA; (B.B.B.); (C.R.)
| | - Cory Riecken
- Arizona State University, College of Health Solutions, Tempe 85281, AZ 85004, USA; (B.B.B.); (C.R.)
| | - Franz X. Vollenweider
- Neuropsychopharamacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital for Psychiatry, Zurich 8032, Switzerland; (K.H.P.); (F.X.V.)
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104
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Bolton TAW, Wotruba D, Buechler R, Theodoridou A, Michels L, Kollias S, Rössler W, Heekeren K, Van De Ville D. Triple Network Model Dynamically Revisited: Lower Salience Network State Switching in Pre-psychosis. Front Physiol 2020; 11:66. [PMID: 32116776 PMCID: PMC7027374 DOI: 10.3389/fphys.2020.00066] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/21/2020] [Indexed: 11/13/2022] Open
Abstract
Emerging evidence has attributed altered network coordination between the default mode, central executive, and salience networks (DMN/CEN/SAL) to disturbances seen in schizophrenia, but little is known for at-risk psychosis stages. Moreover, pinpointing impairments in specific network-to-network interactions, although essential to resolve possibly distinct harbingers of conversion to clinically diagnosed schizophrenia, remains particularly challenging. We addressed this by a dynamic approach to functional connectivity, where right anterior insula brain interactions were examined through co-activation pattern (CAP) analysis. We utilized resting-state fMRI in 19 subjects suffering from subthreshold delusions and hallucinations (UHR), 28 at-risk for psychosis with basic symptoms describing only self-experienced subclinical disturbances (BS), and 29 healthy controls (CTR) matched for age, gender, handedness, and intelligence. We extracted the most recurring CAPs, compared their relative occurrence and average dwell time to probe their temporal expression, and quantified occurrence balance to assess the putative loss of competing relationships. Our findings substantiate the pivotal role of the right anterior insula in governing CEN-to-DMN transitions, which appear dysfunctional prior to the onset of psychosis, especially when first attenuated psychotic symptoms occur. In UHR subjects, it is longer active in concert with the DMN and there is a loss of competition between a SAL/DMN state, and a state with insula/CEN activation paralleled by DMN deactivation. These features suggest that abnormal network switching disrupts one's capacity to distinguish between the internal world and external environment, which is accompanied by inflexibility and an excessive awareness to internal processes reflected by prolonged expression of the right anterior insula-default mode co-activation pattern.
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Affiliation(s)
- Thomas A W Bolton
- Institute of Bioengineering, École Polytechique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology and Medical Informatics, Université de Genève, Geneva, Switzerland
| | - Diana Wotruba
- Collegium Helveticum, ETH Zürich, Zurich, Switzerland.,The Zürich Program for Sustainable Development of Mental Health Services, Psychiatry University Hospital Zürich, Zurich, Switzerland
| | - Roman Buechler
- The Zürich Program for Sustainable Development of Mental Health Services, Psychiatry University Hospital Zürich, Zurich, Switzerland.,Department of Neuroradiology, University Hospital Zürich, Zurich, Switzerland
| | - Anastasia Theodoridou
- The Zürich Program for Sustainable Development of Mental Health Services, Psychiatry University Hospital Zürich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zürich, Zurich, Switzerland
| | - Lars Michels
- Department of Neuroradiology, University Hospital Zürich, Zurich, Switzerland
| | - Spyros Kollias
- Department of Neuroradiology, University Hospital Zürich, Zurich, Switzerland
| | - Wulf Rössler
- Collegium Helveticum, ETH Zürich, Zurich, Switzerland.,The Zürich Program for Sustainable Development of Mental Health Services, Psychiatry University Hospital Zürich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zürich, Zurich, Switzerland.,Institute of Psychiatry, University of São Paulo, São Paulo, Brazil
| | - Karsten Heekeren
- The Zürich Program for Sustainable Development of Mental Health Services, Psychiatry University Hospital Zürich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zürich, Zurich, Switzerland
| | - Dimitri Van De Ville
- Institute of Bioengineering, École Polytechique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology and Medical Informatics, Université de Genève, Geneva, Switzerland
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105
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Mertens LJ, Wall MB, Roseman L, Demetriou L, Nutt DJ, Carhart-Harris RL. Therapeutic mechanisms of psilocybin: Changes in amygdala and prefrontal functional connectivity during emotional processing after psilocybin for treatment-resistant depression. J Psychopharmacol 2020; 34:167-180. [PMID: 31941394 DOI: 10.1177/0269881119895520] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Psilocybin has shown promise as a treatment for depression but its therapeutic mechanisms are not properly understood. In contrast to the presumed actions of antidepressants, we recently found increased amygdala responsiveness to fearful faces one day after open-label treatment with psilocybin (25 mg) in 19 patients with treatment-resistant depression, which correlated with treatment efficacy. AIMS Aiming to further unravel the therapeutic mechanisms of psilocybin, the present study extends this basic activation analysis. We hypothesised changed amygdala functional connectivity, more precisely decreased amygdala-ventromedial prefrontal cortex functional connectivity, during face processing after treatment with psilocybin. METHODS Psychophysiological interaction analyses were conducted on functional magnetic resonance imaging data from a classic face/emotion perception task, with the bilateral amygdala and ventromedial prefrontal cortex time-series as physiological regressors. Average parameter estimates (beta weights) of significant clusters were correlated with clinical outcomes at one week. RESULTS Results showed decreased ventromedial prefrontal cortex-right amygdala functional connectivity during face processing post- (versus pre-) treatment; this decrease was associated with levels of rumination at one week. This effect was driven by connectivity changes in response to fearful and neutral (but not happy) faces. Independent whole-brain analyses also revealed a post-treatment increase in functional connectivity between the amygdala and ventromedial prefrontal cortex to occipital-parietal cortices during face processing. CONCLUSION These results are consistent with the idea that psilocybin therapy revives emotional responsiveness on a neural and psychological level, which may be a key treatment mechanism for psychedelic therapy. Future larger placebo-controlled studies are needed to examine the replicability of the current findings.
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Affiliation(s)
- Lea J Mertens
- Centre for Psychedelic Research, Imperial College London, London, UK
| | - Matthew B Wall
- Centre for Psychedelic Research, Imperial College London, London, UK
- Clinical Psychopharmacology Unit, University College London, London, UK
| | - Leor Roseman
- Centre for Psychedelic Research, Imperial College London, London, UK
- The Computational, Cognitive and Clinical Neuroimaging Laboratory (C3NL), Imperial College London, London, UK
| | - Lysia Demetriou
- Invicro, Hammersmith Hospital, London, UK
- Investigative Medicine, Imperial College London, London, UK
| | - David J Nutt
- Centre for Psychedelic Research, Imperial College London, London, UK
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106
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Transformative experience and social connectedness mediate the mood-enhancing effects of psychedelic use in naturalistic settings. Proc Natl Acad Sci U S A 2020; 117:2338-2346. [PMID: 31964815 DOI: 10.1073/pnas.1918477117] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Past research suggests that use of psychedelic substances such as LSD or psilocybin may have positive effects on mood and feelings of social connectedness. These psychological effects are thought to be highly sensitive to context, but robust and direct evidence for them in a naturalistic setting is scarce. In a series of field studies involving over 1,200 participants across six multiday mass gatherings in the United States and the United Kingdom, we investigated the effects of psychedelic substance use on transformative experience, social connectedness, and positive mood. This approach allowed us to test preregistered hypotheses with high ecological validity and statistical precision. Controlling for a host of demographic variables and the use of other psychoactive substances, we found that psychedelic substance use was significantly associated with positive mood-an effect sequentially mediated by self-reported transformative experience and increased social connectedness. These effects were particularly pronounced for those who had taken psychedelic substances within the last 24 h (compared to the last week). Overall, this research provides robust evidence for positive affective and social consequences of psychedelic substance use in naturalistic settings.
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107
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Hayes SC, Law S, Malady M, Zhu Z, Bai X. The centrality of sense of self in psychological flexibility processes: What the neurobiological and psychological correlates of psychedelics suggest. JOURNAL OF CONTEXTUAL BEHAVIORAL SCIENCE 2020. [DOI: 10.1016/j.jcbs.2019.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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108
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Ho JT, Preller KH, Lenggenhager B. Neuropharmacological modulation of the aberrant bodily self through psychedelics. Neurosci Biobehav Rev 2020; 108:526-541. [DOI: 10.1016/j.neubiorev.2019.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/18/2019] [Accepted: 12/04/2019] [Indexed: 12/13/2022]
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109
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Russo M, Carrarini C, Dono F, Rispoli MG, Di Pietro M, Di Stefano V, Ferri L, Bonanni L, Sensi SL, Onofrj M. The Pharmacology of Visual Hallucinations in Synucleinopathies. Front Pharmacol 2019; 10:1379. [PMID: 31920635 PMCID: PMC6913661 DOI: 10.3389/fphar.2019.01379] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 10/30/2019] [Indexed: 12/13/2022] Open
Abstract
Visual hallucinations (VH) are commonly found in the course of synucleinopathies like Parkinson's disease and dementia with Lewy bodies. The incidence of VH in these conditions is so high that the absence of VH in the course of the disease should raise questions about the diagnosis. VH may take the form of early and simple phenomena or appear with late and complex presentations that include hallucinatory production and delusions. VH are an unmet treatment need. The review analyzes the past and recent hypotheses that are related to the underlying mechanisms of VH and then discusses their pharmacological modulation. Recent models for VH have been centered on the role played by the decoupling of the default mode network (DMN) when is released from the control of the fronto-parietal and salience networks. According to the proposed model, the process results in the perception of priors that are stored in the unconscious memory and the uncontrolled emergence of intrinsic narrative produced by the DMN. This DMN activity is triggered by the altered functioning of the thalamus and involves the dysregulated activity of the brain neurotransmitters. Historically, dopamine has been indicated as a major driver for the production of VH in synucleinopathies. In that context, nigrostriatal dysfunctions have been associated with the VH onset. The efficacy of antipsychotic compounds in VH treatment has further supported the notion of major involvement of dopamine in the production of the hallucinatory phenomena. However, more recent studies and growing evidence are also pointing toward an important role played by serotonergic and cholinergic dysfunctions. In that respect, in vivo and post-mortem studies have now proved that serotonergic impairment is often an early event in synucleinopathies. The prominent cholinergic impairment in DLB is also well established. Finally, glutamatergic and gamma aminobutyric acid (GABA)ergic modulations and changes in the overall balance between excitatory and inhibitory signaling are also contributing factors. The review provides an extensive overview of the pharmacology of VH and offers an up to date analysis of treatment options.
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Affiliation(s)
- Mirella Russo
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Claudia Carrarini
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Fedele Dono
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Marianna Gabriella Rispoli
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Martina Di Pietro
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Vincenzo Di Stefano
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Laura Ferri
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Laura Bonanni
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Stefano Luca Sensi
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
- Behavioral Neurology and Molecular Neurology Units, Center of Excellence on Aging and Translational Medicine—CeSI-MeT, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
- Departments of Neurology and Pharmacology, Institute for Mind Impairments and Neurological Disorders—iMIND, University of California, Irvine, Irvine, CA, United States
| | - Marco Onofrj
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
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110
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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
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111
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Smigielski L, Kometer M, Scheidegger M, Krähenmann R, Huber T, Vollenweider FX. Characterization and prediction of acute and sustained response to psychedelic psilocybin in a mindfulness group retreat. Sci Rep 2019; 9:14914. [PMID: 31649304 PMCID: PMC6813317 DOI: 10.1038/s41598-019-50612-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/16/2019] [Indexed: 01/07/2023] Open
Abstract
Meditation and psychedelics have played key roles in humankind's search for self-transcendence and personal change. However, neither their possible synergistic effects, nor related state and trait predictors have been experimentally studied. To elucidate these issues, we administered double-blind the model psychedelic drug psilocybin (315 μg/kg PO) or placebo to meditators (n = 39) during a 5-day mindfulness group retreat. Psilocybin increased meditation depth and incidence of positively experienced self-dissolution along the perception-hallucination continuum, without concomitant anxiety. Openness, optimism, and emotional reappraisal were predictors of the acute response. Compared with placebo, psilocybin enhanced post-intervention mindfulness and produced larger positive changes in psychosocial functioning at a 4-month follow-up, which were corroborated by external ratings, and associated with magnitude of acute self-dissolution experience. Meditation seems to enhance psilocybin's positive effects while counteracting possible dysphoric responses. These findings highlight the interactions between non-pharmacological and pharmacological factors, and the role of emotion/attention regulation in shaping the experiential quality of psychedelic states, as well as the experience of selflessness as a modulator of behavior and attitudes. A better comprehension of mechanisms underlying most beneficial psychedelic experiences may guide therapeutic interventions across numerous mental conditions in the form of psychedelic-assisted applications.
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Affiliation(s)
- Lukasz Smigielski
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Lenggstrasse 31, CH-8032, Zurich, Switzerland.
| | - Michael Kometer
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Lenggstrasse 31, CH-8032, Zurich, Switzerland
| | - Milan Scheidegger
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Lenggstrasse 31, CH-8032, Zurich, Switzerland
| | - Rainer Krähenmann
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Lenggstrasse 31, CH-8032, Zurich, Switzerland
| | - Theo Huber
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Lenggstrasse 31, CH-8032, Zurich, Switzerland
| | - Franz X Vollenweider
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Lenggstrasse 31, CH-8032, Zurich, Switzerland
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112
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Pallavicini C, Vilas MG, Villarreal M, Zamberlan F, Muthukumaraswamy S, Nutt D, Carhart-Harris R, Tagliazucchi E. Spectral signatures of serotonergic psychedelics and glutamatergic dissociatives. Neuroimage 2019; 200:281-291. [DOI: 10.1016/j.neuroimage.2019.06.053] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 01/23/2023] Open
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113
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Luoma JB, Sabucedo P, Eriksson J, Gates N, Pilecki BC. Toward a contextual psychedelic-assisted therapy: Perspectives from Acceptance and Commitment Therapy and contextual behavioral science. JOURNAL OF CONTEXTUAL BEHAVIORAL SCIENCE 2019. [DOI: 10.1016/j.jcbs.2019.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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114
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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]
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115
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van Elk M, Arciniegas Gomez MA, van der Zwaag W, van Schie HT, Sauter D. The neural correlates of the awe experience: Reduced default mode network activity during feelings of awe. Hum Brain Mapp 2019; 40:3561-3574. [PMID: 31062899 PMCID: PMC6766853 DOI: 10.1002/hbm.24616] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 01/17/2023] Open
Abstract
In the present fMRI study, we aimed to obtain insight into the key brain networks involved in the experience of awe-a complex emotion that is typically elicited by perceptually vast stimuli. Participants were presented with awe-eliciting, positive and neutral videos, while they were instructed to get fully absorbed in the scenery or to count the number of perspective changes. By using a whole-brain analysis we found that several brain regions that are considered part of the default mode network (DMN), including the frontal pole, the angular gyrus, and the posterior cingulate cortex, were more strongly activated in the absorption condition. But this was less the case when participants were watching awe videos. We suggest that while watching awe videos, participants were deeply immersed in the videos and that levels of self-reflective thought were as much reduced during the awe videos, as during the perspective counting condition. In contrast, key regions of the fronto-parietal network (FPN), including the supramarginal gyrus, the medial frontal gyrus, and the insula, were most strongly activated in the analytical condition when participants were watching awe compared to positive and neutral videos. This finding underlines the captivating, immersive, and attention-grabbing nature of awe stimuli that is considered to be responsible for reductions in self-reflective thought. Together these findings suggest that a key feature of the experience of awe is a reduced engagement in self-referential processing, in line with the subjective self-report measures (i.e., participants perceived their self to be smaller).
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Affiliation(s)
- Michiel van Elk
- Department of PsychologyUniversity of AmsterdamAmsterdamthe Netherlands
- Amsterdam Brain and Cognition CenterUniversity of AmsterdamAmsterdamthe Netherlands
| | | | - Wietske van der Zwaag
- Amsterdam Brain and Cognition CenterUniversity of AmsterdamAmsterdamthe Netherlands
- Spinoza Center for NeuroimagingRoyal Netherlands Academy of Arts and SciencesAmsterdamthe Netherlands
| | - Hein T. van Schie
- Behavioral Science InstituteRadboud University NijmegenNijmegenthe Netherlands
| | - Disa Sauter
- Department of PsychologyUniversity of AmsterdamAmsterdamthe Netherlands
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116
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Smigielski L, Scheidegger M, Kometer M, Vollenweider FX. Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects. Neuroimage 2019; 196:207-215. [DOI: 10.1016/j.neuroimage.2019.04.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 03/31/2019] [Accepted: 04/02/2019] [Indexed: 12/27/2022] Open
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117
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Carhart-Harris RL, Friston KJ. REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics. Pharmacol Rev 2019; 71:316-344. [PMID: 31221820 PMCID: PMC6588209 DOI: 10.1124/pr.118.017160] [Citation(s) in RCA: 363] [Impact Index Per Article: 72.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This paper formulates the action of psychedelics by integrating the free-energy principle and entropic brain hypothesis. We call this formulation relaxed beliefs under psychedelics (REBUS) and the anarchic brain, founded on the principle that-via their entropic effect on spontaneous cortical activity-psychedelics work to relax the precision of high-level priors or beliefs, thereby liberating bottom-up information flow, particularly via intrinsic sources such as the limbic system. We assemble evidence for this model and show how it can explain a broad range of phenomena associated with the psychedelic experience. With regard to their potential therapeutic use, we propose that psychedelics work to relax the precision weighting of pathologically overweighted priors underpinning various expressions of mental illness. We propose that this process entails an increased sensitization of high-level priors to bottom-up signaling (stemming from intrinsic sources), and that this heightened sensitivity enables the potential revision and deweighting of overweighted priors. We end by discussing further implications of the model, such as that psychedelics can bring about the revision of other heavily weighted high-level priors, not directly related to mental health, such as those underlying partisan and/or overly-confident political, religious, and/or philosophical perspectives. SIGNIFICANCE STATEMENT: Psychedelics are capturing interest, with efforts underway to bring psilocybin therapy to marketing authorisation and legal access within a decade, spearheaded by the findings of a series of phase 2 trials. In this climate, a compelling unified model of how psychedelics alter brain function to alter consciousness would have appeal. Towards this end, we have sought to integrate a leading model of global brain function, hierarchical predictive coding, with an often-cited model of the acute action of psychedelics, the entropic brain hypothesis. The resulting synthesis states that psychedelics work to relax high-level priors, sensitising them to liberated bottom-up information flow, which, with the right intention, care provision and context, can help guide and cultivate the revision of entrenched pathological priors.
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Affiliation(s)
- R L Carhart-Harris
- Centre for Psychedelic Research, Division of Brain Sciences, Imperial College London, London, United Kingdom (R.L.C.-H.); and Institute of Neurology, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom (K.J.F.)
| | - K J Friston
- Centre for Psychedelic Research, Division of Brain Sciences, Imperial College London, London, United Kingdom (R.L.C.-H.); and Institute of Neurology, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom (K.J.F.)
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118
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Johnson MW, Hendricks PS, Barrett FS, Griffiths RR. Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function. Pharmacol Ther 2019; 197:83-102. [DOI: 10.1016/j.pharmthera.2018.11.010] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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119
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Effective connectivity changes in LSD-induced altered states of consciousness in humans. Proc Natl Acad Sci U S A 2019; 116:2743-2748. [PMID: 30692255 PMCID: PMC6377471 DOI: 10.1073/pnas.1815129116] [Citation(s) in RCA: 149] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Lysergic acid diethylamide (LSD) is a psychedelic drug that reliably induces an altered state of consciousness. Interest in psychedelic compounds is growing due to their remarkable potential for understanding altered neural states and potential clinical applications. However, there are major knowledge gaps regarding LSD’s neuropharmacology. Using cutting-edge neuroimaging methods we investigated directed connectivity between cortico–striato–thalamo-cortical (CSTC) regions after administration of LSD together with the specific role of the serotonin 2A receptor. Our results provide evidence that LSD alters directed connectivity within CSTC pathways in humans, suggesting that a disintegration of information processing within these loops is underlying the psychedelic state. These results inform the neurobiology of altered states of consciousness with critical implications for rational development of novel treatments. Psychedelics exert unique effects on human consciousness. The thalamic filter model suggests that core effects of psychedelics may result from gating deficits, based on a disintegration of information processing within cortico–striato–thalamo-cortical (CSTC) feedback loops. To test this hypothesis, we characterized changes in directed (effective) connectivity between selected CTSC regions after acute administration of lysergic acid diethylamide (LSD), and after pretreatment with Ketanserin (a selective serotonin 2A receptor antagonist) plus LSD in a double-blind, randomized, placebo-controlled, cross-over study in 25 healthy participants. We used spectral dynamic causal modeling (DCM) for resting-state fMRI data. Fully connected DCM models were specified for each treatment condition to investigate the connectivity between the following areas: thalamus, ventral striatum, posterior cingulate cortex, and temporal cortex. Our results confirm major predictions proposed in the CSTC model and provide evidence that LSD alters effective connectivity within CSTC pathways that have been implicated in the gating of sensory and sensorimotor information to the cortex. In particular, LSD increased effective connectivity from the thalamus to the posterior cingulate cortex in a way that depended on serotonin 2A receptor activation, and decreased effective connectivity from the ventral striatum to the thalamus independently of serotonin 2A receptor activation. Together, these results advance our mechanistic understanding of the action of psychedelics in health and disease. This is important for the development of new pharmacological therapeutics and also increases our understanding of the mechanisms underlying the potential clinical efficacy of psychedelics.
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120
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Phenomenal, bodily and brain correlates of fictional reappraisal as an implicit emotion regulation strategy. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2019; 19:877-897. [PMID: 30610654 DOI: 10.3758/s13415-018-00681-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The ability to modulate our emotional experience, depending on our current goal and context, is of critical importance for adaptive behavior. This ability encompasses various emotion regulation strategies, such as fictional reappraisal, at stake whenever one engages in fictional works (e.g., movies, books, video games, virtual environments). Neuroscientific studies investigating the distinction between the processing of real and fictional entities have reported the involvement of brain structures related to self-relevance and emotion regulation, suggesting a threefold interaction between the appraisal of reality, aspects of the Self, and emotions. The main aim of this study is to investigate the effect of implicit fictional reappraisal on different components of emotion, as well as on the modulatory role of autobiographical and conceptual self-relevance. While recording electrodermal, cardiac, and brain activity (EEG), we presented negative and neutral pictures to 33 participants, describing them as either real or fictional. After each stimulus, the participants reported their subjective emotional experience, self-relevance of the stimuli, as well as their agreement with their description. Using the Bayesian mixed-modeling framework, we showed that stimuli presented as fictional, compared with real, were subjectively appraised as less intense and less negative, and elicited lower skin conductance response, stronger heart-rate deceleration, and lower late positive potential amplitudes. Finally, these phenomenal and physiological changes did, to a moderate extent, rely on variations of specific aspects of self-relevance. Implications for the neuroscientific study of implicit emotion regulation are discussed.
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121
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Jalal B. The neuropharmacology of sleep paralysis hallucinations: serotonin 2A activation and a novel therapeutic drug. Psychopharmacology (Berl) 2018; 235:3083-3091. [PMID: 30288594 PMCID: PMC6208952 DOI: 10.1007/s00213-018-5042-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/17/2018] [Indexed: 12/21/2022]
Abstract
Sleep paralysis is a state of involuntary immobility occurring at sleep onset or offset, often accompanied by uncanny "ghost-like" hallucinations and extreme fear reactions. I provide here a neuropharmacological account for these hallucinatory experiences by evoking the role of the serotonin 2A receptor (5-HT2AR). Research has shown that 5-HT2AR activation can induce visual hallucinations, "mystical" subjective states, and out-of-body experiences (OBEs), and modulate fear circuits. Hallucinatory experiences triggered by serotonin-serotonergic ("pseudo") hallucinations, induced by hallucinogenic drugs-tend to be "dream-like" with the experiencer having insight ("meta-awareness") that he is hallucinating, unlike dopaminergic ("psychotic" and "life-like") hallucinations where such insight is lost. Indeed, hallucinatory experiences during sleep paralysis have the classic features of serotonergic hallucinations, and are strikingly similar to perceptual and subjective states induced by hallucinogenic drugs (e.g., lysergic acid diethylamide [LSD] and psilocybin), i.e., they entail visual hallucinations, mystical experiences, OBEs, and extreme fear reactions. I propose a possible mechanism whereby serotonin could be functionally implicated in generating sleep paralysis hallucinations and fear reactions through 5-HT2AR activity. Moreover, I speculate on the role of 5-HT2C receptors vis-à-vis anxiety and panic during sleep paralysis, and the orbitofrontal cortex-rich with 5-HT2A receptors-in influencing visual pathways during sleep paralysis, and, in effect, hallucinations. Finally, I propose, for the first time, a drug to target sleep paralysis hallucinations and fear reactions, namely the selective 5-HT2AR inverse agonist, pimavanserin. This account implicates gene HTR2A on chromosome 13q as the underlying cause of sleep paralysis hallucinations and could be explored using positron emission tomography.
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Affiliation(s)
- Baland Jalal
- Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
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122
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Carhart-Harris RL. The entropic brain - revisited. Neuropharmacology 2018; 142:167-178. [DOI: 10.1016/j.neuropharm.2018.03.010] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/15/2018] [Accepted: 03/12/2018] [Indexed: 12/13/2022]
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123
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Barrett FS, Griffiths RR. Classic Hallucinogens and Mystical Experiences: Phenomenology and Neural Correlates. Curr Top Behav Neurosci 2018; 36:393-430. [PMID: 28401522 PMCID: PMC6707356 DOI: 10.1007/7854_2017_474] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This chapter begins with a brief review of descriptions and definitions of mystical-type experiences and the historical connection between classic hallucinogens and mystical experiences. The chapter then explores the empirical literature on experiences with classic hallucinogens in which claims about mystical or religious experiences have been made. A psychometrically validated questionnaire is described for the reliable measurement of mystical-type experiences occasioned by classic hallucinogens. Controlled laboratory studies show that under double-blind conditions that provide significant controls for expectancy bias, psilocybin can occasion complete mystical experiences in the majority of people studied. These effects are dose-dependent, specific to psilocybin compared to placebo or a psychoactive control substance, and have enduring impact on the moods, attitudes, and behaviors of participants as assessed by self-report of participants and ratings by community observers. Other studies suggest that enduring personal meaning in healthy volunteers and therapeutic outcomes in patients, including reduction and cessation of substance abuse behaviors and reduction of anxiety and depression in patients with a life-threatening cancer diagnosis, are related to the occurrence of mystical experiences during drug sessions. The final sections of the chapter draw parallels in human neuroscience research between the neural bases of experiences with classic hallucinogens and the neural bases of meditative practices for which claims of mystical-type experience are sometimes made. From these parallels, a functional neural model of mystical experience is proposed, based on changes in the default mode network of the brain that have been observed after the administration of classic hallucinogens and during meditation practices for which mystical-type claims have been made.
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Affiliation(s)
- Frederick S Barrett
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224, USA.
| | - Roland R Griffiths
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD, 21224, USA
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124
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Bayne T, Carter O. Dimensions of consciousness and the psychedelic state. Neurosci Conscious 2018; 2018:niy008. [PMID: 30254752 PMCID: PMC6146157 DOI: 10.1093/nc/niy008] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/06/2018] [Accepted: 07/02/2018] [Indexed: 01/21/2023] Open
Abstract
It has often been suggested in the popular and academic literature that the psychedelic state qualifies as a higher state of consciousness relative to the state of normal waking awareness. This article subjects this proposal to critical scrutiny, focusing on the question of what it would mean for a state of consciousness to be 'higher'. We begin by considering the contrast between conscious contents and conscious global states. We then review the changes in conscious global state associated with psychedelic drug use, focusing on the effects of two serotonergic hallucinogens: psilocybin and lysergic acid diethylamide. Limiting our review to findings obtained from lab-based experiments and reported in peer-reviewed journals, we prioritize the more common and reliably induced effects obtained through subjective questionnaires and psychophysical measures. The findings are grouped into three broad categories (sensory perception, cognitive function, and experiences of unity) and demonstrate that although certain aspects of consciousness are improved or enhanced in the psychedelic state, many of the functional capacities that are associated with consciousness are seriously compromised. Psychedelic-induced states of consciousness are indeed remarkable in many ways, but it is inappropriate to regard them as 'higher' states of consciousness. The fact that psychedelics affect different aspects of consciousness in fundamentally different ways provides evidence against the unidimensional (or 'level-based') view of consciousness, and instead provides strong support for a multidimensional conception of conscious states. The final section of the article considers the implications of this analysis for two prominent theories of consciousness: the Global Workspace Theory and Integrated Information Theory.
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Affiliation(s)
- Tim Bayne
- School of Philosophical, Historical and International Studies, 20 Chancellors Walk, Monash University, VIC, Australia
| | - Olivia Carter
- School of Psychological Sciences, University of Melbourne, Parkville, VIC, Australia
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125
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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.
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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
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126
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General anaesthesia as fragmentation of selfhood: insights from electroencephalography and neuroimaging. Br J Anaesth 2018; 121:233-240. [DOI: 10.1016/j.bja.2017.12.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/18/2017] [Accepted: 12/19/2017] [Indexed: 11/20/2022] Open
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127
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Eischens P, Atherton WL. Psychedelic therapy as a complementary treatment approach for alcohol use disorders. JOURNAL OF PSYCHEDELIC STUDIES 2018. [DOI: 10.1556/2054.2018.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Peter Eischens
- Department of Addictions & Rehabilitation Studies, East Carolina University, Health Sciences Building, Greenville, NC, USA
| | - William Leigh Atherton
- Department of Addictions & Rehabilitation Studies, East Carolina University, Health Sciences Building, Greenville, NC, USA
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128
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Winkelman MJ. An ontology of psychedelic entity experiences in evolutionary psychology and neurophenomenology. JOURNAL OF PSYCHEDELIC STUDIES 2018. [DOI: 10.1556/2054.2018.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Michael James Winkelman
- Retired, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
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129
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Franquesa A, Sainz-Cort A, Gandy S, Soler J, Alcázar-Córcoles MÁ, Bouso JC. Psychological variables implied in the therapeutic effect of ayahuasca: A contextual approach. Psychiatry Res 2018; 264:334-339. [PMID: 29674223 DOI: 10.1016/j.psychres.2018.04.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 03/05/2018] [Accepted: 04/02/2018] [Indexed: 11/15/2022]
Abstract
Ayahuasca is a psychedelic decoction originating from Amazonia. The ayahuasca-induced introspective experience has been shown to have potential benefits in the treatment of several pathologies, to protect mental health and to improve neuropsychological functions and creativity, and boost mindfulness. The underlying psychological processes related to the use of ayahuasca in a psychotherapeutic context are not yet well described in the scientific literature, but there is some evidence to suggest that psychological variables described in psychotherapies could be useful in explaining the therapeutic effects of the brew. In this study we explore the link between ayahuasca use and Decentering, Values and Self, comparing subjects without experience of ayahuasca (n = 41) with subjects with experience (n = 81). Results confirm that ayahuasca users scored higher than non-users in Decentering and Positive self, but not in Valued living, Life fulfillment, Self in social relations, Self in close relations and General self. Scores in Decentering were higher in the more experienced subjects (more than 15 occasions) than in those with less experience (less than 15 occasions). Our results show that psychological process variables may explain the outcomes in ayahuasca psychotherapy. The introduction of these variables is warranted in future ayahuasca therapeutic studies.
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Affiliation(s)
- Alba Franquesa
- Les Corts Centre d'Higiene Mental, Barcelona, Spain; Departament de Psiquiatria i Medicina Legal, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Alberto Sainz-Cort
- International Center for Ethnobotanical Education, Research & Service, Barcelona, Spain
| | - Sam Gandy
- The College of Life Sciences and Medicine, University of Aberdeen, UK
| | - Joaquim Soler
- Servei de Psiquiatria, Hospital de la Santa Creu i Sant Pau (Barcelona), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain; Departamento de Psicologia Clínica i de la Salut, Universitat Autònoma de Barcelona, Barcelona, Spain
| | | | - José Carlos Bouso
- International Center for Ethnobotanical Education, Research & Service, Barcelona, Spain.
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130
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Nielson EM, May DG, Forcehimes AA, Bogenschutz MP. The Psychedelic Debriefing in Alcohol Dependence Treatment: Illustrating Key Change Phenomena through Qualitative Content Analysis of Clinical Sessions. Front Pharmacol 2018. [PMID: 29515449 PMCID: PMC5826346 DOI: 10.3389/fphar.2018.00132] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Research on the clinical applications of psychedelic-assisted psychotherapy has demonstrated promising early results for treatment of alcohol dependence. Detailed description of the content and methods of psychedelic-assisted psychotherapy, as it is conducted in clinical settings, is scarce. Methods: An open-label pilot (proof-of-concept) study of psilocybin-assisted treatment of alcohol dependence (NCT01534494) was conducted to generate data for a phase 2 RCT (NCT02061293) of a similar treatment in a larger population. The present paper presents a qualitative content analysis of the 17 debriefing sessions conducted in the pilot study, which occurred the day after corresponding psilocybin medication sessions. Results: Participants articulated a series of key phenomena related to change in drinking outcomes and acute subjective effects of psilocybin. Discussion: The data illuminate change processes in patients' own words during clinical sessions, shedding light on potential therapeutic mechanisms of change and how participants express effects of psilocybin. This study is unique in analyzing actual clinical sessions, as opposed to interviews of patients conducted separately from treatment.
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Affiliation(s)
- Elizabeth M Nielson
- Department of Psychiatry, NYU School of Medicine, New York University, New York, NY, United States
| | - Darrick G May
- Department of Psychiatry & Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | | | - Michael P Bogenschutz
- Department of Psychiatry, NYU School of Medicine, New York University, New York, NY, United States
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131
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Sanz C, Zamberlan F, Erowid E, Erowid F, Tagliazucchi E. The Experience Elicited by Hallucinogens Presents the Highest Similarity to Dreaming within a Large Database of Psychoactive Substance Reports. Front Neurosci 2018; 12:7. [PMID: 29403350 PMCID: PMC5786560 DOI: 10.3389/fnins.2018.00007] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/04/2018] [Indexed: 01/19/2023] Open
Abstract
Ever since the modern rediscovery of psychedelic substances by Western society, several authors have independently proposed that their effects bear a high resemblance to the dreams and dreamlike experiences occurring naturally during the sleep-wake cycle. Recent studies in humans have provided neurophysiological evidence supporting this hypothesis. However, a rigorous comparative analysis of the phenomenology (“what it feels like” to experience these states) is currently lacking. We investigated the semantic similarity between a large number of subjective reports of psychoactive substances and reports of high/low lucidity dreams, and found that the highest-ranking substance in terms of the similarity to high lucidity dreams was the serotonergic psychedelic lysergic acid diethylamide (LSD), whereas the highest-ranking in terms of the similarity to dreams of low lucidity were plants of the Datura genus, rich in deliriant tropane alkaloids. Conversely, sedatives, stimulants, antipsychotics, and antidepressants comprised most of the lowest-ranking substances. An analysis of the most frequent words in the subjective reports of dreams and hallucinogens revealed that terms associated with perception (“see,” “visual,” “face,” “reality,” “color”), emotion (“fear”), setting (“outside,” “inside,” “street,” “front,” “behind”) and relatives (“mom,” “dad,” “brother,” “parent,” “family”) were the most prevalent across both experiences. In summary, we applied novel quantitative analyses to a large volume of empirical data to confirm the hypothesis that, among all psychoactive substances, hallucinogen drugs elicit experiences with the highest semantic similarity to those of dreams. Our results and the associated methodological developments open the way to study the comparative phenomenology of different altered states of consciousness and its relationship with non-invasive measurements of brain physiology.
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Affiliation(s)
- Camila Sanz
- Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | | | | | - Enzo Tagliazucchi
- Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina.,Brain and Spine Institute, Paris, France
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132
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Roseman L, Nutt DJ, Carhart-Harris RL. Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression. Front Pharmacol 2018; 8:974. [PMID: 29387009 PMCID: PMC5776504 DOI: 10.3389/fphar.2017.00974] [Citation(s) in RCA: 355] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 12/20/2017] [Indexed: 12/13/2022] Open
Abstract
Introduction: It is a basic principle of the “psychedelic” treatment model that the quality of the acute experience mediates long-term improvements in mental health. In the present paper we sought to test this using data from a clinical trial assessing psilocybin for treatment-resistant depression (TRD). In line with previous reports, we hypothesized that the occurrence and magnitude of Oceanic Boundlessness (OBN) (sharing features with mystical-type experience) and Dread of Ego Dissolution (DED) (similar to anxiety) would predict long-term positive outcomes, whereas sensory perceptual effects would have negligible predictive value. Materials and Methods: Twenty patients with treatment resistant depression underwent treatment with psilocybin (two separate sessions: 10 and 25 mg psilocybin). The Altered States of Consciousness (ASC) questionnaire was used to assess the quality of experiences in the 25 mg psilocybin session. From the ASC, the dimensions OBN and DED were used to measure the mystical-type and challenging experiences, respectively. The Self-Reported Quick Inventory of Depressive Symptoms (QIDS-SR) at 5 weeks served as the endpoint clinical outcome measure, as in later time points some of the subjects had gone on to receive new treatments, thus confounding inferences. In a repeated measure ANOVA, Time was the within-subject factor (independent variable), with QIDS-SR as the within-subject dependent variable in baseline, 1-day, 1-week, 5-weeks. OBN and DED were independent variables. OBN-by-Time and DED-by-Time interactions were the primary outcomes of interest. Results: For the interaction of OBN and DED with Time (QIDS-SR as dependent variable), the main effect and the effects at each time point compared to baseline were all significant (p = 0.002 and p = 0.003, respectively, for main effects), confirming our main hypothesis. Furthermore, Pearson's correlation of OBN with QIDS-SR (5 weeks) was specific compared to perceptual dimensions of the ASC (p < 0.05). Discussion: This report further bolsters the view that the quality of the acute psychedelic experience is a key mediator of long-term changes in mental health. Future therapeutic work with psychedelics should recognize the essential importance of quality of experience in determining treatment efficacy and consider ways of enhancing mystical-type experiences and reducing anxiety. Trial Registration: ISRCTN, number ISRCTN14426797, http://www.isrctn.com/ISRCTN14426797
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Affiliation(s)
- Leor Roseman
- Psychedelic Research Group, Department of Medicine, Imperial College London, London, United Kingdom
| | - David J Nutt
- Psychedelic Research Group, Department of Medicine, Imperial College London, London, United Kingdom
| | - Robin L Carhart-Harris
- Psychedelic Research Group, Department of Medicine, Imperial College London, London, United Kingdom
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133
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Dakwar E, Nunes EV, Hart CL, Hu MC, Foltin RW, Levin FR. A sub-set of psychoactive effects may be critical to the behavioral impact of ketamine on cocaine use disorder: Results from a randomized, controlled laboratory study. Neuropharmacology 2018; 142:270-276. [PMID: 29309770 DOI: 10.1016/j.neuropharm.2018.01.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/27/2017] [Accepted: 01/04/2018] [Indexed: 01/01/2023]
Abstract
Efforts to translate sub-anesthetic ketamine infusions into widespread clinical use have centered around developing medications with comparable neurobiological activity, but with attenuated psychoactive effects so as to minimize the risk of behavioral toxicity and abuse liability. Converging lines of research, however, suggest that some of the psychoactive effects of sub-anesthetic ketamine may have therapeutic potential. Here, we assess whether a subset of these effects - the so-called mystical-type experience - mediates the effect of ketamine on craving and cocaine use in cocaine dependent research volunteers. We found that ketamine leads to significantly greater acute mystical-type effects (by Hood Mysticism Scale: HMS), dissociation (by Clinician Administered Dissociative States Scale: CADSS), and near-death experience phenomena (by the Near-Death Experience Scale: NDES), relative to the active control midazolam. HMS score, but not the CADSS or NDES score, was found to mediate the effect of ketamine on global improvement (decreased cocaine use and craving) over the post-infusion period. This is the first controlled study to show that mystical-type phenomena, long considered to have therapeutic potential, may work to impact decision-making and behavior in a sustained manner. These data suggest that an important direction for medication development is the identification of ketamine-like pharmacotherapy that is selectively psychoactive (as opposed to free of experiential effects entirely), so that mystical-type perspectival shifts are more reliably produced and factors lending to abuse or behavioral impairment are minimized. Future research can further clarify the relationship between medication-occasioned mystical-type effects and clinical benefit for different disorders. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.
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Affiliation(s)
- E Dakwar
- New York State Psychiatric Institute, Columbia University College of Physicians and Surgeons, USA.
| | - E V Nunes
- New York State Psychiatric Institute, Columbia University College of Physicians and Surgeons, USA
| | - C L Hart
- New York State Psychiatric Institute, Columbia University College of Physicians and Surgeons, USA; Department of Psychology, Columbia University, USA
| | - M C Hu
- Department of Psychology, Columbia University, USA
| | - R W Foltin
- New York State Psychiatric Institute, Columbia University College of Physicians and Surgeons, USA
| | - F R Levin
- New York State Psychiatric Institute, Columbia University College of Physicians and Surgeons, USA
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The renaissance in psychedelic research: What do preclinical models have to offer. PROGRESS IN BRAIN RESEARCH 2018; 242:25-67. [DOI: 10.1016/bs.pbr.2018.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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136
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Kraehenmann R, Pokorny D, Aicher H, Preller KH, Pokorny T, Bosch OG, Seifritz E, Vollenweider FX. LSD Increases Primary Process Thinking via Serotonin 2A Receptor Activation. Front Pharmacol 2017; 8:814. [PMID: 29167644 PMCID: PMC5682333 DOI: 10.3389/fphar.2017.00814] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/27/2017] [Indexed: 01/21/2023] Open
Abstract
Rationale: Stimulation of serotonin 2A (5-HT2A) receptors by lysergic acid diethylamide (LSD) and related compounds such as psilocybin has previously been shown to increase primary process thinking - an ontologically and evolutionary early, implicit, associative, and automatic mode of thinking which is typically occurring during altered states of consciousness such as dreaming. However, it is still largely unknown whether LSD induces primary process thinking under placebo-controlled, standardized experimental conditions and whether these effects are related to subjective experience and 5-HT2A receptor activation. Therefore, this study aimed to test the hypotheses that LSD increases primary process thinking and that primary process thinking depends on 5-HT2A receptor activation and is related to subjective drug effects. Methods: Twenty-five healthy subjects performed an audio-recorded mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). The main outcome variable in this study was primary index (PI), a formal measure of primary process thinking in the imagery reports. State of consciousness was evaluated using the Altered State of Consciousness (5D-ASC) rating scale. Results: LSD, compared with placebo, significantly increased primary index (p < 0.001, Bonferroni-corrected). The LSD-induced increase in primary index was positively correlated with LSD-induced disembodiment (p < 0.05, Bonferroni-corrected), and blissful state (p < 0.05, Bonferroni-corrected) on the 5D-ASC. Both LSD-induced increases in primary index and changes in state of consciousness were fully blocked by ketanserin. Conclusion: LSD induces primary process thinking via activation of 5-HT2A receptors and in relation to disembodiment and blissful state. Primary process thinking appears to crucially organize inner experiences during both dreams and psychedelic states of consciousness.
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Affiliation(s)
- Rainer Kraehenmann
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland.,Neuropsychopharmacology and Brain Imaging Unit, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
| | - Dan Pokorny
- Department of Psychosomatic Medicine and Psychotherapy, University of Ulm, Ulm, Germany
| | - Helena Aicher
- Neuropsychopharmacology and Brain Imaging Unit, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
| | - Katrin H Preller
- Neuropsychopharmacology and Brain Imaging Unit, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
| | - Thomas Pokorny
- Neuropsychopharmacology and Brain Imaging Unit, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
| | - Oliver G Bosch
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
| | - Erich Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
| | - Franz X Vollenweider
- Neuropsychopharmacology and Brain Imaging Unit, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zürich, Switzerland
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137
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Winkelman MJ. The Mechanisms of Psychedelic Visionary Experiences: Hypotheses from Evolutionary Psychology. Front Neurosci 2017; 11:539. [PMID: 29033783 PMCID: PMC5625021 DOI: 10.3389/fnins.2017.00539] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 09/15/2017] [Indexed: 12/20/2022] Open
Abstract
Neuropharmacological effects of psychedelics have profound cognitive, emotional, and social effects that inspired the development of cultures and religions worldwide. Findings that psychedelics objectively and reliably produce mystical experiences press the question of the neuropharmacological mechanisms by which these highly significant experiences are produced by exogenous neurotransmitter analogs. Humans have a long evolutionary relationship with psychedelics, a consequence of psychedelics' selective effects for human cognitive abilities, exemplified in the information rich visionary experiences. Objective evidence that psychedelics produce classic mystical experiences, coupled with the finding that hallucinatory experiences can be induced by many non-drug mechanisms, illustrates the need for a common model of visionary effects. Several models implicate disturbances of normal regulatory processes in the brain as the underlying mechanisms responsible for the similarities of visionary experiences produced by psychedelic and other methods for altering consciousness. Similarities in psychedelic-induced visionary experiences and those produced by practices such as meditation and hypnosis and pathological conditions such as epilepsy indicate the need for a general model explaining visionary experiences. Common mechanisms underlying diverse alterations of consciousness involve the disruption of normal functions of the prefrontal cortex and default mode network (DMN). This interruption of ordinary control mechanisms allows for the release of thalamic and other lower brain discharges that stimulate a visual information representation system and release the effects of innate cognitive functions and operators. Converging forms of evidence support the hypothesis that the source of psychedelic experiences involves the emergence of these innate cognitive processes of lower brain systems, with visionary experiences resulting from the activation of innate processes based in the mirror neuron system (MNS).
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Affiliation(s)
- Michael J Winkelman
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States
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138
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Ahlskog R. Moral Enhancement Should Target Self-Interest and Cognitive Capacity. NEUROETHICS-NETH 2017; 10:363-373. [PMID: 28890738 PMCID: PMC5569152 DOI: 10.1007/s12152-017-9331-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 04/07/2017] [Indexed: 11/29/2022]
Abstract
Current suggestions for capacities that should be targeted for moral enhancement has centered on traits like empathy, fairness or aggression. The literature, however, lacks a proper model for understanding the interplay and complexity of moral capacities, which limits the practicability of proposed interventions. In this paper, I integrate some existing knowledge on the nature of human moral behavior and present a formal model of prosocial motivation. The model provides two important results regarding the most friction-free route to moral enhancement. First, we should consider decreasing self-interested motivation rather than increasing prosociality directly. Second, this should be complemented with cognitive enhancement. These suggestions are tested against existing and emerging evidence on cognitive capacity, mindfulness meditation and the effects of psychedelic drugs and are found to have sufficient grounding for further theoretical and empirical exploration. Furthermore, moral effects of the latter two are hypothesized to result from a diminished sense of self with subsequent reductions in self-interest.
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Affiliation(s)
- Rafael Ahlskog
- Department of Government, Uppsala Universitet, Uppsala, Sweden
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139
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Kraehenmann R, Pokorny D, Vollenweider L, Preller KH, Pokorny T, Seifritz E, Vollenweider FX. Dreamlike effects of LSD on waking imagery in humans depend on serotonin 2A receptor activation. Psychopharmacology (Berl) 2017; 234:2031-2046. [PMID: 28386699 DOI: 10.1007/s00213-017-4610-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 03/20/2017] [Indexed: 01/15/2023]
Abstract
RATIONALE Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered state of consciousness that resembles dreaming. OBJECTIVES This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. METHODS Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. RESULTS LSD, compared with placebo, significantly increased cognitive bizarreness (p < 0.001). The LSD-induced increase in cognitive bizarreness was positively correlated with the LSD-induced loss of self-boundaries and cognitive control (p < 0.05). Both LSD-induced increases in cognitive bizarreness and changes in state of consciousness were fully blocked by ketanserin. CONCLUSIONS LSD produced mental imagery similar to dreaming, primarily via activation of the 5-HT2A receptor and in relation to loss of self-boundaries and cognitive control. Future psychopharmacological studies should assess the differential contribution of the D2/D1 and 5-HT1A receptors to cognitive bizarreness.
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Affiliation(s)
- Rainer Kraehenmann
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland. .,Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Lenggstrasse 31, 8032, Zurich, Switzerland.
| | - Dan Pokorny
- Department of Psychosomatic Medicine and Psychotherapy, University of Ulm, Ulm, Germany
| | - Leonie Vollenweider
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Lenggstrasse 31, 8032, Zurich, Switzerland
| | - Katrin H Preller
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Lenggstrasse 31, 8032, Zurich, Switzerland
| | - Thomas Pokorny
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Lenggstrasse 31, 8032, Zurich, Switzerland
| | - Erich Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Franz X Vollenweider
- Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Lenggstrasse 31, 8032, Zurich, Switzerland
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140
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Letheby C, Gerrans P. Self unbound: ego dissolution in psychedelic experience. Neurosci Conscious 2017; 2017:nix016. [PMID: 30042848 PMCID: PMC6007152 DOI: 10.1093/nc/nix016] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 04/21/2017] [Accepted: 05/15/2017] [Indexed: 11/26/2022] Open
Abstract
Users of psychedelic drugs often report that their sense of being a self or ‘I’ distinct from the rest of the world has diminished or altogether dissolved. Neuroscientific study of such ‘ego dissolution’ experiences offers a window onto the nature of self-awareness. We argue that ego dissolution is best explained by an account that explains self-awareness as resulting from the integrated functioning of hierarchical predictive models which posit the existence of a stable and unchanging entity to which representations are bound. Combining recent work on the ‘integrative self' and the phenomenon of self-binding with predictive processing principles yields an explanation of ego dissolution according to which self-representation is a useful Cartesian fiction: an ultimately false representation of a simple and enduring substance to which attributes are bound which serves to integrate and unify cognitive processing across levels and domains. The self-model is not a mere narrative posit, as some have suggested; it has a more robust and ubiquitous cognitive function than that. But this does not mean, as others have claimed, that the self-model has the right attributes to qualify as a self. It performs some of the right kinds of functions, but it is not the right kind of entity. Ego dissolution experiences reveal that the self-model plays an important binding function in cognitive processing, but the self does not exist.
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Affiliation(s)
- Chris Letheby
- Department of Philosophy, University of Adelaide, North Terrace, Adelaide, South Australia 5005, Australia
| | - Philip Gerrans
- Department of Philosophy, University of Adelaide, North Terrace, Adelaide, South Australia 5005, Australia
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141
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Millière R. Looking for the Self: Phenomenology, Neurophysiology and Philosophical Significance of Drug-induced Ego Dissolution. Front Hum Neurosci 2017; 11:245. [PMID: 28588463 PMCID: PMC5441112 DOI: 10.3389/fnhum.2017.00245] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 04/25/2017] [Indexed: 12/17/2022] Open
Abstract
There is converging evidence that high doses of hallucinogenic drugs can produce significant alterations of self-experience, described as the dissolution of the sense of self and the loss of boundaries between self and world. This article discusses the relevance of this phenomenon, known as “drug-induced ego dissolution (DIED)”, for cognitive neuroscience, psychology and philosophy of mind. Data from self-report questionnaires suggest that three neuropharmacological classes of drugs can induce ego dissolution: classical psychedelics, dissociative anesthetics and agonists of the kappa opioid receptor (KOR). While these substances act on different neurotransmitter receptors, they all produce strong subjective effects that can be compared to the symptoms of acute psychosis, including ego dissolution. It has been suggested that neuroimaging of DIED can indirectly shed light on the neural correlates of the self. While this line of inquiry is promising, its results must be interpreted with caution. First, neural correlates of ego dissolution might reveal the necessary neurophysiological conditions for the maintenance of the sense of self, but it is more doubtful that this method can reveal its minimally sufficient conditions. Second, it is necessary to define the relevant notion of self at play in the phenomenon of DIED. This article suggests that DIED consists in the disruption of subpersonal processes underlying the “minimal” or “embodied” self, i.e., the basic experience of being a self rooted in multimodal integration of self-related stimuli. This hypothesis is consistent with Bayesian models of phenomenal selfhood, according to which the subjective structure of conscious experience ultimately results from the optimization of predictions in perception and action. Finally, it is argued that DIED is also of particular interest for philosophy of mind. On the one hand, it challenges theories according to which consciousness always involves self-awareness. On the other hand, it suggests that ordinary conscious experience might involve a minimal kind of self-awareness rooted in multisensory processing, which is what appears to fade away during DIED.
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Affiliation(s)
- Raphaël Millière
- Faculty of Philosophy, University of OxfordOxford, United Kingdom
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142
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Sabucedo P. The Psychological Flexibility Model from a cultural perspective: an interpretative analysis of two Native American healing rituals. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/17542863.2017.1323935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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143
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van Elk M, Aleman A. Brain mechanisms in religion and spirituality: An integrative predictive processing framework. Neurosci Biobehav Rev 2017; 73:359-378. [DOI: 10.1016/j.neubiorev.2016.12.031] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 11/10/2016] [Accepted: 12/26/2016] [Indexed: 12/21/2022]
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Affiliation(s)
- Paul Summergrad
- Tufts University School of Medicine, Tufts Medical Center, Boston, MA, USA
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145
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Dos Santos RG, Osório FL, Crippa JAS, Hallak JEC. Classical hallucinogens and neuroimaging: A systematic review of human studies: Hallucinogens and neuroimaging. Neurosci Biobehav Rev 2016; 71:715-728. [PMID: 27810345 DOI: 10.1016/j.neubiorev.2016.10.026] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/29/2016] [Accepted: 10/27/2016] [Indexed: 01/07/2023]
Abstract
Serotonergic hallucinogens produce alterations of perceptions, mood, and cognition, and have anxiolytic, antidepressant, and antiaddictive properties. These drugs act as agonists of frontocortical 5-HT2A receptors, but the neural basis of their effects are not well understood. Thus, we conducted a systematic review of neuroimaging studies analyzing the effects of serotonergic hallucinogens in man. Studies published in the PubMed, Lilacs, and SciELO databases until 12 April 2016 were included using the following keywords: "ayahuasca", "DMT", "psilocybin", "LSD", "mescaline" crossed one by one with the terms "mri", "fmri", "pet", "spect", "imaging" and "neuroimaging". Of 279 studies identified, 25 were included. Acute effects included excitation of frontolateral/frontomedial cortex, medial temporal lobe, and occipital cortex, and inhibition of the default mode network. Long-term use was associated with thinning of the posterior cingulate cortex, thickening of the anterior cingulate cortex, and decreased neocortical 5-HT2A receptor binding. Despite the high methodological heterogeneity and the small sample sizes, the results suggest that hallucinogens increase introspection and positive mood by modulating brain activity in the fronto-temporo-parieto-occipital cortex.
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Affiliation(s)
- Rafael G Dos Santos
- Department of Neuroscience and Behavior, Ribeirão Preto Medical School, University of São Paulo, SP, Brazil.
| | - Flávia L Osório
- Department of Neuroscience and Behavior, Ribeirão Preto Medical School, University of São Paulo, SP, Brazil; National Institute for Translational Medicine (INCT-TM), CNPq, Brazil
| | - José Alexandre S Crippa
- Department of Neuroscience and Behavior, Ribeirão Preto Medical School, University of São Paulo, SP, Brazil; National Institute for Translational Medicine (INCT-TM), CNPq, Brazil
| | - Jaime E C Hallak
- Department of Neuroscience and Behavior, Ribeirão Preto Medical School, University of São Paulo, SP, Brazil; National Institute for Translational Medicine (INCT-TM), CNPq, Brazil
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146
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Bogenschutz MP, Forcehimes AA. Development of a Psychotherapeutic Model for Psilocybin-Assisted Treatment of Alcoholism. JOURNAL OF HUMANISTIC PSYCHOLOGY 2016. [DOI: 10.1177/0022167816673493] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Research activity on the potential clinical value of classic hallucinogens and other psychedelics has increased markedly in the past two decades, and promises to continue to expand. Experimental study of hallucinogen-assisted treatment, and any future clinical use, requires the development of psychotherapeutic models that are appropriate to the disorder being treated and effectively integrated with the pharmacologic component of the treatment. To provide a framework for thinking about possible treatment models, we provide an overview of the history of psychedelic-assisted treatment, review what is known about the therapeutic mechanisms of these treatments, and consider the various purposes of psychotherapy in the context of both research and clinical use of psychedelic-assisted treatment. We then provide a description of a therapy model we have developed and are currently using in a trial of psilocybin-assisted treatment for alcoholism. Finally, we discuss advantages and disadvantages of a range of alternative models, emphasizing the need for research to determine the most effective treatment models for any indications for which efficacy becomes established.
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147
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Nour MM, Evans L, Nutt D, Carhart-Harris RL. Ego-Dissolution and Psychedelics: Validation of the Ego-Dissolution Inventory (EDI). Front Hum Neurosci 2016; 10:269. [PMID: 27378878 PMCID: PMC4906025 DOI: 10.3389/fnhum.2016.00269] [Citation(s) in RCA: 193] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/20/2016] [Indexed: 02/05/2023] Open
Abstract
AIMS The experience of a compromised sense of "self", termed ego-dissolution, is a key feature of the psychedelic experience. This study aimed to validate the Ego-Dissolution Inventory (EDI), a new 8-item self-report scale designed to measure ego-dissolution. Additionally, we aimed to investigate the specificity of the relationship between psychedelics and ego-dissolution. METHOD Sixteen items relating to altered ego-consciousness were included in an internet questionnaire; eight relating to the experience of ego-dissolution (comprising the EDI), and eight relating to the antithetical experience of increased self-assuredness, termed ego-inflation. Items were rated using a visual analog scale. Participants answered the questionnaire for experiences with classical psychedelic drugs, cocaine and/or alcohol. They also answered the seven questions from the Mystical Experiences Questionnaire (MEQ) relating to the experience of unity with one's surroundings. RESULTS Six hundred and ninety-one participants completed the questionnaire, providing data for 1828 drug experiences (1043 psychedelics, 377 cocaine, 408 alcohol). Exploratory factor analysis demonstrated that the eight EDI items loaded exclusively onto a single common factor, which was orthogonal to a second factor comprised of the items relating to ego-inflation (rho = -0.110), demonstrating discriminant validity. The EDI correlated strongly with the MEQ-derived measure of unitive experience (rho = 0.735), demonstrating convergent validity. EDI internal consistency was excellent (Cronbach's alpha 0.93). Three analyses confirmed the specificity of ego-dissolution for experiences occasioned by psychedelic drugs. Firstly, EDI score correlated with drug-dose for psychedelic drugs (rho = 0.371), but not for cocaine (rho = 0.115) or alcohol (rho = -0.055). Secondly, the linear regression line relating the subjective intensity of the experience to ego-dissolution was significantly steeper for psychedelics (unstandardized regression coefficient = 0.701) compared with cocaine (0.135) or alcohol (0.144). Ego-inflation, by contrast, was specifically associated with cocaine experiences. Finally, a binary Support Vector Machine classifier identified experiences occasioned by psychedelic drugs vs. cocaine or alcohol with over 85% accuracy using ratings of ego-dissolution and ego-inflation alone. CONCLUSION Our results demonstrate the psychometric structure, internal consistency and construct validity of the EDI. Moreover, we demonstrate the close relationship between ego-dissolution and the psychedelic experience. The EDI will facilitate the study of the neuronal correlates of ego-dissolution, which is relevant for psychedelic-assisted psychotherapy and our understanding of psychosis.
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Affiliation(s)
- Matthew M Nour
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Imperial College LondonLondon, UK; Institute of Psychiatry Psychology and Neuroscience, King's College LondonLondon, UK
| | - Lisa Evans
- Faculty of Medicine, Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London London, UK
| | - David Nutt
- Faculty of Medicine, Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London London, UK
| | - Robin L Carhart-Harris
- Faculty of Medicine, Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London London, UK
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148
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Lebedev AV, Kaelen M, Lövdén M, Nilsson J, Feilding A, Nutt DJ, Carhart-Harris RL. LSD-induced entropic brain activity predicts subsequent personality change. Hum Brain Mapp 2016; 37:3203-13. [PMID: 27151536 DOI: 10.1002/hbm.23234] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/24/2016] [Accepted: 04/18/2016] [Indexed: 02/05/2023] Open
Abstract
Personality is known to be relatively stable throughout adulthood. Nevertheless, it has been shown that major life events with high personal significance, including experiences engendered by psychedelic drugs, can have an enduring impact on some core facets of personality. In the present, balanced-order, placebo-controlled study, we investigated biological predictors of post-lysergic acid diethylamide (LSD) changes in personality. Nineteen healthy adults underwent resting state functional MRI scans under LSD (75µg, I.V.) and placebo (saline I.V.). The Revised NEO Personality Inventory (NEO-PI-R) was completed at screening and 2 weeks after LSD/placebo. Scanning sessions consisted of three 7.5-min eyes-closed resting-state scans, one of which involved music listening. A standardized preprocessing pipeline was used to extract measures of sample entropy, which characterizes the predictability of an fMRI time-series. Mixed-effects models were used to evaluate drug-induced shifts in brain entropy and their relationship with the observed increases in the personality trait openness at the 2-week follow-up. Overall, LSD had a pronounced global effect on brain entropy, increasing it in both sensory and hierarchically higher networks across multiple time scales. These shifts predicted enduring increases in trait openness. Moreover, the predictive power of the entropy increases was greatest for the music-listening scans and when "ego-dissolution" was reported during the acute experience. These results shed new light on how LSD-induced shifts in brain dynamics and concomitant subjective experience can be predictive of lasting changes in personality. Hum Brain Mapp 37:3203-3213, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- A V Lebedev
- Aging Research Center, Karolinska Institutet (Department of Neurobiology, Care Sciences and Society) & Stockholm University, Stockholm, Sweden
| | - M Kaelen
- Division of Brain Sciences, Department of Medicine, Centre for Neuropsychopharmacology, Imperial College London, United Kingdom
| | - M Lövdén
- Aging Research Center, Karolinska Institutet (Department of Neurobiology, Care Sciences and Society) & Stockholm University, Stockholm, Sweden
| | - J Nilsson
- Aging Research Center, Karolinska Institutet (Department of Neurobiology, Care Sciences and Society) & Stockholm University, Stockholm, Sweden
| | - A Feilding
- The Beckley Foundation, Beckley Park, United Kingdom
| | - D J Nutt
- Division of Brain Sciences, Department of Medicine, Centre for Neuropsychopharmacology, Imperial College London, United Kingdom
| | - R L Carhart-Harris
- Division of Brain Sciences, Department of Medicine, Centre for Neuropsychopharmacology, Imperial College London, United Kingdom
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149
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Carhart-Harris RL, Kaelen M, Bolstridge M, Williams TM, Williams LT, Underwood R, Feilding A, Nutt DJ. The paradoxical psychological effects of lysergic acid diethylamide (LSD). Psychol Med 2016; 46:1379-1390. [PMID: 26847689 DOI: 10.1017/s0033291715002901] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Lysergic acid diethylamide (LSD) is a potent serotonergic hallucinogen or psychedelic that modulates consciousness in a marked and novel way. This study sought to examine the acute and mid-term psychological effects of LSD in a controlled study. METHOD A total of 20 healthy volunteers participated in this within-subjects study. Participants received LSD (75 µg, intravenously) on one occasion and placebo (saline, intravenously) on another, in a balanced order, with at least 2 weeks separating sessions. Acute subjective effects were measured using the Altered States of Consciousness questionnaire and the Psychotomimetic States Inventory (PSI). A measure of optimism (the Revised Life Orientation Test), the Revised NEO Personality Inventory, and the Peter's Delusions Inventory were issued at baseline and 2 weeks after each session. RESULTS LSD produced robust psychological effects; including heightened mood but also high scores on the PSI, an index of psychosis-like symptoms. Increased optimism and trait openness were observed 2 weeks after LSD (and not placebo) and there were no changes in delusional thinking. CONCLUSIONS The present findings reinforce the view that psychedelics elicit psychosis-like symptoms acutely yet improve psychological wellbeing in the mid to long term. It is proposed that acute alterations in mood are secondary to a more fundamental modulation in the quality of cognition, and that increased cognitive flexibility subsequent to serotonin 2A receptor (5-HT2AR) stimulation promotes emotional lability during intoxication and leaves a residue of 'loosened cognition' in the mid to long term that is conducive to improved psychological wellbeing.
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Affiliation(s)
- R L Carhart-Harris
- Imperial College London,Centre for Neuropsychopharmacology,Division of Brain Sciences,Faculty of Medicine,London,UK
| | - M Kaelen
- Imperial College London,Centre for Neuropsychopharmacology,Division of Brain Sciences,Faculty of Medicine,London,UK
| | - M Bolstridge
- Imperial College London,Centre for Neuropsychopharmacology,Division of Brain Sciences,Faculty of Medicine,London,UK
| | - T M Williams
- Department of Psychiatry,The University of Bristol,Bristol,UK
| | - L T Williams
- Imperial College London,Centre for Neuropsychopharmacology,Division of Brain Sciences,Faculty of Medicine,London,UK
| | - R Underwood
- Institute of Psychiatry, Psychology & Neuroscience,Department of Psychology,King's College London,London,UK
| | - A Feilding
- The Beckley Foundation,Beckley Park,Oxford,UK
| | - D J Nutt
- Imperial College London,Centre for Neuropsychopharmacology,Division of Brain Sciences,Faculty of Medicine,London,UK
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Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proc Natl Acad Sci U S A 2016; 113:4853-8. [PMID: 27071089 DOI: 10.1073/pnas.1518377113] [Citation(s) in RCA: 420] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD's marked effects on the visual cortex did not significantly correlate with the drug's other characteristic effects on consciousness, however. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of "ego-dissolution" and "altered meaning," implying the importance of this particular circuit for the maintenance of "self" or "ego" and its processing of "meaning." Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others.
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