73 results found
Carhart-Harris RL, 2018, The entropic brain - revisited, Neuropharmacology, ISSN: 0028-3908
© 2018 The entropic brain hypothesis proposes that within upper and lower limits, after which consciousness may be lost, the entropy of spontaneous brain activity indexes the informational richness of conscious states. Here the hypothesis is revisited four years on from its original publication. It is shown that the principle that the entropy of brain activity is elevated in the psychedelic state is increasingly well supported by separate and independent studies and analyses, and evidence for greater brain criticality under psychedelics is also highlighted. It is argued that heightened brain criticality enables the brain to be more sensitive to intrinsic and extrinsic perturbations which may translate as a heightened susceptibility to “set” and “setting”. This updated version of the original entropic brain hypothesis now offers more concrete information on specific measures of brain entropy and suggests new studies to scrutinise it further, as well as examine its utility for describing and informing the treatment of psychiatric and neurological conditions such as depression and disorders of consciousness.
Carhart-Harris RL, Bolstridge M, Day CMJ, et al., 2018, Psilocybin with psychological support for treatment-resistant depression: six-month follow-up, PSYCHOPHARMACOLOGY, Vol: 235, Pages: 399-408, ISSN: 0033-3158
Carhart-Harris RL, Roseman L, Haijen E, et al., 2018, Psychedelics and the essential importance of context., J Psychopharmacol
Psychedelic drugs are making waves as modern trials support their therapeutic potential and various media continue to pique public interest. In this opinion piece, we draw attention to a long-recognised component of the psychedelic treatment model, namely ‘set’ and ‘setting’ – subsumed here under the umbrella term ‘context’. We highlight: (a) the pharmacological mechanisms of classic psychedelics (5-HT2A receptor agonism and associated plasticity) that we believe render their effects exceptionally sensitive to context, (b) a study design for testing assumptions regarding positive interactions between psychedelics and context, and (c) new findings from our group regarding contextual determinants of the quality of a psychedelic experience and how acute experience predicts subsequent long-term mental health outcomes. We hope that this article can: (a) inform on good practice in psychedelic research, (b) provide a roadmap for optimising treatment models, and (c) help tackle unhelpful stigma still surrounding these compounds, while developing an evidence base for long-held assumptions about the critical importance of context in relation to psychedelic use that can help minimise harms and maximise potential benefits.
Carrillo F, Sigman M, Fernandez Slezak D, et al., 2018, Natural speech algorithm applied to baseline interview data can predict which patients will respond to psilocybin for treatment-resistant depression, JOURNAL OF AFFECTIVE DISORDERS, Vol: 230, Pages: 84-86, ISSN: 0165-0327
Kaelen M, Giribaldi B, Raine J, et al., 2018, The hidden therapist: evidence for a central role of music in psychedelic therapy, PSYCHOPHARMACOLOGY, Vol: 235, Pages: 505-519, ISSN: 0033-3158
Kaelen M, Giribaldi B, Raine J, et al., 2018, Correction to: The hidden therapist: evidence for a central role of music in psychedelic therapy., Psychopharmacology (Berl)
The article The hidden therapist: evidence for a central role of music in psychedelic therapy, written by Mendel Kaelen, Bruna Giribaldi, Jordan Raine, Lisa Evans, Christopher Timmerman, Natalie Rodriguez, Leor Roseman, Amanda Feilding, David Nutt, Robin Carhart-Harris, was originally published electronically on the publisher's internet portal.
Lyons T, Carhart-Harris RL, 2018, Increased nature relatedness and decreased authoritarian political views after psilocybin for treatment-resistant depression., J Psychopharmacol
RATIONALE: Previous research suggests that classical psychedelic compounds can induce lasting changes in personality traits, attitudes and beliefs in both healthy subjects and patient populations. AIM: Here we sought to investigate the effects of psilocybin on nature relatedness and libertarian-authoritarian political perspective in patients with treatment-resistant depression (TRD). METHODS: This open-label pilot study with a mixed-model design studied the effects of psilocybin on measures of nature relatedness and libertarian-authoritarian political perspective in patients with moderate to severe TRD ( n=7) versus age-matched non-treated healthy control subjects ( n=7). Psilocybin was administered in two oral dosing sessions (10 mg and 25 mg) 1 week apart. Main outcome measures were collected 1 week and 7-12 months after the second dosing session. Nature relatedness and libertarian-authoritarian political perspective were assessed using the Nature Relatedness Scale (NR-6) and Political Perspective Questionnaire (PPQ-5), respectively. RESULTS: Nature relatedness significantly increased ( t(6)=-4.242, p=0.003) and authoritarianism significantly decreased ( t(6)=2.120, p=0.039) for the patients 1 week after the dosing sessions. At 7-12 months post-dosing, nature relatedness remained significantly increased ( t(5)=-2.707, p=0.021) and authoritarianism remained decreased at trend level ( t(5)=-1.811, p=0.065). No differences were found on either measure for the non-treated healthy control subjects. CONCLUSIONS: This pilot study suggests that psilocybin with psychological support might produce lasting changes in attitudes and beliefs. Although it would be premature to infer causality from this small study, the possibility of drug-induced changes in belief systems seems sufficiently intriguing and timely to deserve further investigation.
Roseman L, Nutt DJ, Carhart-Harris RL, 2018, Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression, FRONTIERS IN PHARMACOLOGY, Vol: 8, ISSN: 1663-9812
Stroud JB, Freeman TP, Leech R, et al., 2018, Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression, PSYCHOPHARMACOLOGY, Vol: 235, Pages: 459-466, ISSN: 0033-3158
Carhart-Harris R, Lawton G, 2017, Trip advisor, NEW SCIENTIST, Vol: 235, Pages: 42-43, ISSN: 0262-4079
Carhart-Harris RL, Goodwin GM, 2017, The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future, Neuropsychopharmacology, Vol: 42, Pages: 2105-2113, ISSN: 0893-133X
Carhart-Harris RL, Nutt DJ, 2017, Serotonin and brain function: a tale of two receptors, JOURNAL OF PSYCHOPHARMACOLOGY, Vol: 31, Pages: 1091-1120, ISSN: 0269-8811
Carhart-Harris RL, Roseman L, Bolstridge M, et al., 2017, Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms, SCIENTIFIC REPORTS, Vol: 7, ISSN: 2045-2322
Erritzoe D, Nutt DJ, Carhart-Harris R, 2017, Concerns regarding conclusions made about LSD-treatments, HISTORY OF PSYCHIATRY, Vol: 28, Pages: 257-258, ISSN: 0957-154X
Nour MM, Carhart-Harris RL, 2017, Psychedelics and the science of self-experience, BRITISH JOURNAL OF PSYCHIATRY, Vol: 210, Pages: 177-179, ISSN: 0007-1250
Nour MM, Evans L, Carhart-Harris RL, 2017, Psychedelics, Personality and Political Perspectives, JOURNAL OF PSYCHOACTIVE DRUGS, Vol: 49, Pages: 182-191, ISSN: 0279-1072
Roseman L, Demetriou L, Wall MB, et al., 2017, Increased amygdala responses to emotional faces after psilocybin for treatment-resistant depression., Neuropharmacology
Recent evidence indicates that psilocybin with psychological support may be effective for treating depression. Some studies have found that patients with depression show heightened amygdala responses to fearful faces and there is reliable evidence that treatment with SSRIs attenuates amygdala responses (Ma, 2015). We hypothesised that amygdala responses to emotional faces would be altered post-treatment with psilocybin. In this open-label study, 20 individuals diagnosed with moderate to severe, treatment-resistant depression, underwent two separate dosing sessions with psilocybin. Psychological support was provided before, during and after these sessions and 19 completed fMRI scans one week prior to the first session and one day after the second and last. Neutral, fearful and happy faces were presented in the scanner and analyses focused on the amygdala. Group results revealed rapid and enduring improvements in depressive symptoms post psilocybin. Increased responses to fearful and happy faces were observed in the right amygdala post-treatment, and right amygdala increases to fearful versus neutral faces were predictive of clinical improvements at 1-week. Psilocybin with psychological support was associated with increased amygdala responses to emotional stimuli, an opposite effect to previous findings with SSRIs. This suggests fundamental differences in these treatments' therapeutic actions, with SSRIs mitigating negative emotions and psilocybin allowing patients to confront and work through them. Based on the present results, we propose that psilocybin with psychological support is a treatment approach that potentially revives emotional responsiveness in depression, enabling patients to reconnect with their emotions. TRIAL REGISTRATION: ISRCTN, number ISRCTN14426797.
Schartner MM, Carhart-Harris RL, Barrett AB, et al., 2017, Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin, Scientific Reports, Vol: 7, Pages: 46421-46421
Timmermann C, Spriggs MJ, Kaelen M, et al., 2017, LSD modulates effective connectivity and neural adaptation mechanisms in an auditory oddball paradigm., Neuropharmacology
Under the predictive coding framework, perceptual learning and inference are dependent on the interaction between top-down predictions and bottom-up sensory signals both between and within regions in a network. However, how such feedback and feedforward connections are modulated in the state induced by lysergic acid diethylamide (LSD) is poorly understood. In this study, an auditory oddball paradigm was presented to healthy participants (16 males, 4 female) under LSD and placebo, and brain activity was recorded using magnetoencephalography (MEG). Scalp level Event Related Fields (ERF) revealed reduced neural adaptation to familiar stimuli, and a blunted neural 'surprise' response to novel stimuli in the LSD condition. Dynamic causal modelling revealed that both the presentation of novel stimuli and LSD modulate backward extrinsic connectivity within a task-activated fronto-temporal network, as well as intrinsic connectivity in the primary auditory cortex. These findings show consistencies with those of previous studies of schizophrenia and ketamine but also studies of reduced consciousness - suggesting that rather than being a marker of conscious level per se, backward connectivity may index modulations of perceptual learning common to a variety of altered states of consciousness, perhaps united by a shared altered sensitivity to environmental stimuli. Since recent evidence suggests that the psychedelic state may correspond to a heightened 'level' of consciousness with respect to the normal waking state, our data warrant a re-examination of the top-down hypotheses of conscious level and suggest that several altered states may feature this specific biophysical effector.
Watts R, Day C, Krzanowski J, et al., 2017, Patients' Accounts of Increased "Connectedness" and "Acceptance" After Psilocybin for Treatment-Resistant Depression, JOURNAL OF HUMANISTIC PSYCHOLOGY, Vol: 57, Pages: 520-564, ISSN: 0022-1678
Carhart-Harris R, 2016, 5-HT2A agonist drugs as new treatments in psychiatry, 29th Congress of the European-College-of-Neuropsychopharmacology (ECNP), Publisher: ELSEVIER SCIENCE BV, Pages: S121-S121, ISSN: 0924-977X
Carhart-Harris RL, Bolstridge M, Rucker J, et al., 2016, Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study, LANCET PSYCHIATRY, Vol: 3, Pages: 619-627, ISSN: 2215-0374
Carhart-Harris RL, Kaelen M, Bolstridge M, et al., 2016, The paradoxical psychological effects of lysergic acid diethylamide (LSD), PSYCHOLOGICAL MEDICINE, Vol: 46, Pages: 1379-1390, ISSN: 0033-2917
Carhart-Harris RL, Muthukumaraswamy S, Roseman L, et al., 2016, Neural correlates of the LSD experience revealed by multimodal neuroimaging, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 113, Pages: 4853-4858, ISSN: 0027-8424
Carhart-Harris RL, Nutt DJ, 2016, Question-based Drug Development for psilocybin Reply, LANCET PSYCHIATRY, Vol: 3, Pages: 807-807, ISSN: 2215-0374
Curran HV, Wall M, Demetriou L, et al., 2016, Effects of ecstasy on autobiographical memories: implications for MDMA assisted psychotherapy, 29th Congress of the European-College-of-Neuropsychopharmacology (ECNP), Publisher: ELSEVIER SCIENCE BV, Pages: S145-S145, ISSN: 0924-977X
Family N, Vinson D, Vigliocco G, et al., 2016, Semantic activation in LSD: evidence from picture naming, LANGUAGE COGNITION AND NEUROSCIENCE, Vol: 31, Pages: 1320-1327, ISSN: 2327-3798
Kaelen M, Roseman L, Kahan J, et al., 2016, LSD modulates music-induced imagery via changes in parahippocampal connectivity, EUROPEAN NEUROPSYCHOPHARMACOLOGY, Vol: 26, Pages: 1099-1109, ISSN: 0924-977X
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