45 results found
INTRODUCTION: Mescaline (3,4,5-trimethoxyphenethylamine) is one of the oldest hallucinogens, with evidence of use dating back 5700 years. Mescaline is a naturally occurring alkaloid found in cacti, mainly in the peyote cactus (Lophophora williamsii) and in the cacti of the Echinopsis genus. Since the prohibition of psychoactive substances in the early 70s, research on mescaline and other classical psychedelics has been limited. OBJECTIVES: This article aims to review the pharmacology and behavioural effects of mescaline, focusing on preclinical and clinical research. FINDINGS: Mescaline is a serotonin 5HT2A/2C receptor agonist, with its main hallucinogenic effects being mediated via its 5HT2A receptor agonist action. It also exerts effects via agonist binding at α1A/2A noradrenaline and D1/2/3 dopamine receptors. Overall, mescaline has anxiolytic-like effects in animals and increases prosocial behaviour, locomotion, and response reactivity. In humans, mescaline can induce euphoria, hallucinations, improvements in well-being and mental health conditions, and psychotomimetic effects in a naturalistic or religious setting. CONCLUSION: The pharmacological mechanisms of mescaline are similar to those of other classical psychedelics, like psilocybin and lysergic acid diethylamide (LSD). Mescaline appears to be safe to consume, with most intoxications being mild and easily treatable. Improvement in mental well-being and its ability to overcome alcoholism render mescaline potentially beneficial in clinical settings. This article is part of the Special Issue on 'Psilocybin Research'.
Singleton SP, Luppi AI, Carhart-Harris RL, et al., 2022, Receptor-informed network control theory links LSD and psilocybin to a flattening of the brain's control energy landscape, NATURE COMMUNICATIONS, Vol: 13
Daws R, Timmermann C, Giribaldi B, et al., 2022, Increased global integration in the brain after psilocybin therapy for depression, Nature Medicine, Vol: 28, ISSN: 1078-8956
Psilocybin therapy shows antidepressant potential, but its therapeutic actions are not well understood. We assessed the sub-acute impact of psilocybin on brain function in two clinical trials of depression. The first was an open-label trial of orally administered psilocybin (10mg and 25mg, 7 days apart) in treatment-resistant depression (TRD). fMRI was recorded at baseline and one day after the 25mg dose. Beck’s depression inventory (BDI) was the primary outcome measure (MR/J00460X/1). The second trial was a double-blind phase 2 randomised control trial (DB-RCT) comparing psilocybin therapy with escitalopram. Major depressive disorder (MDD) patients received either: 2 x 25mg oral psilocybin, 3 weeks apart, plus 6 weeks of daily placebo (‘psilocybin-arm’); or 2 x 1mg oral psilocybin, 3 weeks apart, plus 6 weeks of daily escitalopram [10-20mg] (‘escitalopram-arm’). fMRI wasrecorded at baseline and 3 weeks after the 2nd psilocybin dose (NCT03429075). In both trials, the antidepressant response to psilocybin was rapid, sustained and correlated with decreases in functional MRI (fMRI) brain network modularity, implying that psilocybin’s antidepressant action may depend on a global increase in brainnetwork integration. Network cartography analyses indicated that 5-HT2A receptor rich higher-order functional networks became more functionally inter-connected and flexible post psilocybin. The antidepressant response to escitalopram was milder and no changes in brain network organisation were observed. Consistent efficacy related brain changes, correlating with robust antidepressant effects across two studies, suggest an antidepressant mechanism for psilocybin therapy: Global increases in brain network integration.
Murphy R, Kettner HS, Zeifman R, et al., 2022, Therapeutic alliance and rapport modulate responses to psilocybin assisted therapy for depression, Frontiers in Pharmacology, Vol: 12, Pages: 1-19, ISSN: 1663-9812
Background: Across psychotherapeutic frameworks, the strength of the therapeutic alliance has been found to correlate with treatment outcomes; however, its role has never been formally assessed in a trial of psychedelic-assisted therapy. We aimed to investigate the relationships between therapeutic alliance and rapport, the quality of the acute psychedelic experience and treatment outcomes. Methods: This 2-arm double-blind randomized controlled trial compared escitalopram with psychedelic-assisted therapy for moderate-severe depressive disorder (N=59). This analysis focused on the psilocybin condition (n=30), who received two oral doses of 25 mg psilocybin, three-weeks apart, with psychological preparation, in-session support, and integration therapy. A new psychedelic therapy model, called ‘Accept-Connect-Embody’ (ACE), was developed in this trial. The primary outcome was depression severity six weeks post treatment (Quick Inventory of Depressive Symptomatology, QIDS-SR-16). Path analyses tested the hypothesis that therapeutic alliance (Scale To Assess the Therapeutic Relationship Patient Version, STAR-P) would predict depression outcomes via its influence on the acute psychedelic experience, specifically emotional-breakthrough (EBI) and mystical-type experiences (MEQ). The same analysis was performed on the escitalopram arm to test specificity. Results: The strength of therapeutic alliance predicted pre-session rapport, greater emotional-breakthrough and mystical-type experience (maximum EBI and MEQ scores across the two psilocybin sessions) and final QIDS scores (β = -0.22, R2 = 0.42 for EBIMax; β = -0.19, R2 = 0.32 for MEQMax). Exploratory path models revealed that final depression outcomes were more strongly affected by emotional breakthrough during the first, and mystical experience during the second session. Emotional breakthrough, but not mystical experience, during the first session had a positive effect on therapeutic alliance ahead o
Wall M, Lam C, Ertl N, et al., 2021, The effect of psilocybin therapy for depression on low-frequency brain activity in response to music, 34th European-College-of-Neuropsychopharmacology (ECNP) Congress on Early Career Scientists in Europe, Publisher: ELSEVIER, Pages: S649-S649, ISSN: 0924-977X
Douglass H, Spriggs MJ, Park RJ, et al., 2021, Study protocol: psilocybin as a treatment for anorexia nervosa: a pilot study, 34th European-College-of-Neuropsychopharmacology (ECNP) Congress on Early Career Scientists in Europe, Publisher: ELSEVIER, Pages: S257-S258, ISSN: 0924-977X
Spriggs M, Douglass H, Park R, et al., 2021, Study protocol for “Psilocybin as a Treatment for Anorexia Nervosa: A Pilot Study", Frontiers in Psychiatry, Vol: 12, Pages: 1-16, ISSN: 1664-0640
Background: Anorexia nervosa (AN) is a serious and life-threatening psychiatric condition. With a paucity of approved treatments, there is a desperate need for novel treatment avenues to be explored. Here, we present 1) an overview of the ways through which Public Patient Involvement (PPI) has informed a trial of psilocybin-assisted therapy for AN and 2) aprotocol for a pilot study of psilocybin-assisted therapy in AN currently underway at Imperial College London. The study aims to assess the feasibility, brain mechanisms and preliminary outcomes of treating anorexia nervosa with psilocybin. Methods: 1) PPI: Across two online focus groups, eleven individuals with lived experience of AN were presented with an overview of the protocol. Their feedback not only identified solutions to possible barriers for future participants, but also helped the research team to better understand the concept of “recovery” from the perspective of those with lived experience. 2) Protocol: Over a 6-week period, twenty female participants (21-65 years old,body mass index (BMI) ³15kg/m2) will receive three oral doses of psilocybin (up to 25 mg) delivered in a therapeutic environment and enveloped by psychological preparation and integration. We will work with participant support networks (care teams and an identified support person) throughout and there will be an extended remote follow-up period of 12 months. Our twofold primary outcomes are 1) psychopathology (Eating Disorder Examination) across the 6-month follow-up and 2) readiness and motivation to engage in recovery (Readiness and Motivation Questionnaire) across the 6-week trial period. Neurophysiological outcome measures will be: 1) functional magnetic resonance imaging (fMRI) brain changes from baseline to 6-week endpoint and 2) post-acute changes in electroencephalography (EEG) activity, including an electrophysiological marker of neuronal plasticity. Discussion: The results of this pilot study will not only shed
Carhart-Harris R, Blemings A, Nutt DJ, 2021, Psilocybin for Depression, NEW ENGLAND JOURNAL OF MEDICINE, Vol: 385, Pages: 863-864, ISSN: 0028-4793
Singleton SP, Luppi AI, Carhart-Harris RL, et al., 2021, LSD and psilocybin flatten the brain’s energy landscape: insights from receptor-informed network control theory
<jats:title>Abstract</jats:title><jats:p>Psychedelics like lysergic acid diethylamide (LSD) and psilocybin offer a powerful window into the function of the human brain and mind, by temporarily altering subjective experience through their neurochemical effects. A recent model postulates that serotonin 2a (5-HT2a) receptor agonism allows the brain to explore its dynamic landscape more readily, as reflected by more diverse (entropic) brain activity. We postulate that this increase in entropy may arise in part from a flattening of the brain’s control energy landscape, which can be observed using network control theory to quantify the energy required to transition between recurrent brain states measured using functional magnetic resonance imaging (fMRI) in individuals under LSD, psilocybin, and placebo conditions. We show that LSD and psilocybin reduce the amount of control energy required for brain state transitions, and, furthermore, that, across individuals, LSD’s reduction in control energy correlates with more frequent state transitions and increased entropy of brain state dynamics. Through network control analysis that incorporates the spatial distribution of 5-HT2a receptors from publicly available (non-drug) positron emission tomography (PET) maps, we demonstrate the specific role of this receptor in reducing control energy. Our findings provide evidence that 5-HT2a receptor agonist compounds allow for more facile state transitions and more temporally diverse brain activity. More broadly, by combining receptor-informed network control theory with pharmacological modulation, our work highlights the potential of this approach in studying the impacts of targeted neuropharmacological manipulation on brain activity dynamics.</jats:p><jats:sec><jats:title>Significance Statement</jats:title><jats:p>We present a multi-modal framework for quantifying the effects of two psychedelic drugs (LSD and psilocybin) on br
Carhart-Harris R, Giribaldi B, Watts R, et al., 2021, Trial of Psilocybin versus Escitalopram for Depression, NEW ENGLAND JOURNAL OF MEDICINE, Vol: 384, Pages: 1402-1411, ISSN: 0028-4793
Mertens LJ, Wall MB, Roseman L, et al., 2020, Therapeutic mechanisms of psilocybin: Changes in amygdala and prefrontal functional connectivity during emotional processing after psilocybin for treatment-resistant depression, JOURNAL OF PSYCHOPHARMACOLOGY, Vol: 34, Pages: 167-180, ISSN: 0269-8811
Mertens LJ, Wall MB, Roseman L, et al., 2019, Therapeutic mechanisms of psychedelic drugs: Changes in amygdala and prefrontal functional connectivity during emotional processing after psilocybin for treatment-resistant depression, 32nd Congress of the European-College-of-Neuropsychopharmacology (ECNP), Publisher: ELSEVIER, Pages: S416-S417, ISSN: 0924-977X
Lord L-D, Expert P, Atasoy S, et al., 2019, Dynamical exploration of the repertoire of brain networks at rest is modulated by psilocybin, NeuroImage, Vol: 199, Pages: 127-142, ISSN: 1053-8119
Growing evidence from the dynamical analysis of functional neuroimaging data suggests that brain function can be understood as the exploration of a repertoire of metastable connectivity patterns ('functional brain networks'), which potentially underlie different mental processes. The present study characterizes how the brain's dynamical exploration of resting-state networks is rapidly modulated by intravenous infusion of psilocybin, a tryptamine psychedelic found in "magic mushrooms". We employed a data-driven approach to characterize recurrent functional connectivity patterns by focusing on the leading eigenvector of BOLD phase coherence at single-TR resolution. Recurrent BOLD phase-locking patterns (PL states) were assessed and statistically compared pre- and post-infusion of psilocybin in terms of their probability of occurrence and transition profiles. Results were validated using a placebo session. Recurrent BOLD PL states revealed high spatial overlap with canonical resting-state networks. Notably, a PL state forming a frontoparietal subsystem was strongly destabilized after psilocybin injection, with a concomitant increase in the probability of occurrence of another PL state characterized by global BOLD phase coherence. These findings provide evidence of network-specific neuromodulation by psilocybin and represent one of the first attempts at bridging molecular pharmacodynamics and whole-brain network dynamics.
Jefsen O, Hojgaard K, Christiansen SL, et al., 2019, Psilocybin lacks antidepressant-like effect in the Flinders Sensitive Line rat, ACTA NEUROPSYCHIATRICA, Vol: 31, Pages: 213-219, ISSN: 1601-5215
Erritzoe D, Roseman L, Nour MM, et al., 2018, Effects of psilocybin therapy on personality structure, Acta Psychiatrica Scandinavica, Vol: 138, Pages: 368-378, ISSN: 1600-0447
ObjectiveTo explore whether psilocybin with psychological support modulates personality parameters in patients suffering from treatment‐resistant depression (TRD).MethodTwenty patients with moderate or severe, unipolar, TRD received oral psilocybin (10 and 25 mg, one week apart) in a supportive setting. Personality was assessed at baseline and at 3‐month follow‐up using the Revised NEO Personality Inventory (NEO‐PI‐R), the subjective psilocybin experience with Altered State of Consciousness (ASC) scale, and depressive symptoms with QIDS‐SR16.ResultsNeuroticism scores significantly decreased while Extraversion increased following psilocybin therapy. These changes were in the direction of the normative NEO‐PI‐R data and were both predicted, in an exploratory analysis, by the degree of insightfulness experienced during the psilocybin session. Openness scores also significantly increased following psilocybin, whereas Conscientiousness showed trend‐level increases, and Agreeableness did not change.ConclusionOur observation of changes in personality measures after psilocybin therapy was mostly consistent with reports of personality change in relation to conventional antidepressant treatment, although the pronounced increases in Extraversion and Openness might constitute an effect more specific to psychedelic therapy. This needs further exploration in future controlled studies, as do the brain mechanisms of postpsychedelic personality change.
Rucker JJH, Iliff J, Nutt DJ, 2018, Psychiatry & the psychedelic drugs. Past, present & future, Neuropharmacology, Vol: 142, Pages: 200-218, ISSN: 0028-3908
The classical psychedelic drugs, including psilocybin, lysergic acid diethylamide and mescaline, were used extensively in psychiatry before they were placed in Schedule I of the UN Convention on Drugs in 1967. Experimentation and clinical trials undertaken prior to legal sanction suggest that they are not helpful for those with established psychotic disorders and should be avoided in those liable to develop them. However, those with so-called 'psychoneurotic' disorders sometimes benefited considerably from their tendency to 'loosen' otherwise fixed, maladaptive patterns of cognition and behaviour, particularly when given in a supportive, therapeutic setting. Pre-prohibition studies in this area were sub-optimal, although a recent systematic review in unipolar mood disorder and a meta-analysis in alcoholism have both suggested efficacy. The incidence of serious adverse events appears to be low. Since 2006, there have been several pilot trials and randomised controlled trials using psychedelics (mostly psilocybin) in various non-psychotic psychiatric disorders. These have provided encouraging results that provide initial evidence of safety and efficacy, however the regulatory and legal hurdles to licensing psychedelics as medicines are formidable. This paper summarises clinical trials using psychedelics pre and post prohibition, discusses the methodological challenges of performing good quality trials in this area and considers a strategic approach to the legal and regulatory barriers to licensing psychedelics as a treatment in mainstream psychiatry.
Roseman L, Demetriou L, Wall M, et al., 2018, Increased amygdala responses to emotional faces after psilocybin for treatment-resistant depression, Neuropharmacology, Vol: 142, Pages: 263-269, ISSN: 0028-3908
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.
Gabay AS, Carhart-Harris RL, Mazibuko N, et al., 2018, Psilocybin and MDMA reduce costly punishment in the Ultimatum Game, SCIENTIFIC REPORTS, Vol: 8, ISSN: 2045-2322
Disruptions in social decision-making are becoming evident in many psychiatric conditions. These are studied using paradigms investigating the psychological mechanisms underlying interpersonal interactions, such as the Ultimatum Game (UG). Rejection behaviour in the UG represents altruistic punishment – the costly punishment of norm violators – but the mechanisms underlying it require clarification. To investigate the psychopharmacology of UG behaviour, we carried out two studies with healthy participants, employing serotonergic agonists: psilocybin (open-label, within-participant design, N = 19) and 3,4-methylenedioxymethamphetamine (MDMA; placebo-controlled, double-blind, crossover design, N = 20). We found that both MDMA and psilocybin reduced rejection of unfair offers (odds ratio: 0.57 and 0.42, respectively). The reduction in rejection rate following MDMA was associated with increased prosociality (R2 = 0.26, p = 0.025). In the MDMA study, we investigated third-party decision-making and proposer behaviour. MDMA did not reduce rejection in the third-party condition, but produced an increase in the amount offered to others (Cohen’s d = 0.82). We argue that these compounds altered participants’ conceptualisation of ‘social reward’, placing more emphasis on the direct relationship with interacting partners. With these compounds showing efficacy in drug-assisted psychotherapy, these studies are an important step in the further characterisation of their psychological effects.
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
RationaleRecent studies have supported the safety and efficacy of psychedelic therapy for mood disorders and addiction. Music is considered an important component in the treatment model, but little empirical research has been done to examine the magnitude and nature of its therapeutic role.ObjectivesThe present study assessed the influence of music on the acute experience and clinical outcomes of psychedelic therapy.MethodsSemi-structured interviews inquired about the different ways in which music influenced the experience of 19 patients undergoing psychedelic therapy with psilocybin for treatment-resistant depression. Interpretative phenomenological analysis was applied to the interview data to identify salient themes. In addition, ratings were given for each patient for the extent to which they expressed “liking,” “resonance” (the music being experienced as “harmonious” with the emotional state of the listener), and “openness” (acceptance of the music-evoked experience).ResultsAnalyses of the interviews revealed that the music had both “welcome” and “unwelcome” influences on patients’ subjective experiences. Welcome influences included the evocation of personally meaningful and therapeutically useful emotion and mental imagery, a sense of guidance, openness, and the promotion of calm and a sense of safety. Conversely, unwelcome influences included the evocation of unpleasant emotion and imagery, a sense of being misguided and resistance. Correlation analyses showed that patients’ experience of the music was associated with the occurrence of “mystical experiences” and “insightfulness.” Crucially, the nature of the music experience was significantly predictive of reductions in depression 1 week after psilocybin, whereas general drug intensity was not.ConclusionsThis study indicates that music plays a central therapeutic function in psychedelic therapy.
Roseman L, Nutt DJ, Carhart-Harris RL, et al., 2018, Quality of acute psychedelic experience predicts therapeutic efficacy of psilocybin for treatment-resistant depression, Frontiers in Pharmacology, Vol: 8, ISSN: 1663-9812
Introduction: It is a basic principle of the ‘psychedelic’ treatment model that the quality of the acute experience mediateslong-term improvements in mental health. In the present paper we sought to test this using data from a clinical trial assessingpsilocybin for treatment-resistant depression (TRD). In line with previous reports, we hypothesized that the occurrence andmagnitude 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 not.Material and Methods: Twenty patients with treatment resistant depression underwent treatment with psilocybin (two separatesessions: 10mg and 25mg psilocybin). The Altered States of Consciousness (ASC) questionnaire was used to assess the quality ofexperiences in the 25mg psilocybin session. From the ASC, the dimensions OBN and DED were used to measure the mystical-typeand challenging experiences, respectively. The Self-Reported Quick Inventory of Depressive Symptoms (QIDS-SR) at 5 weeks servedas 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), withQIDS-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 timepoint compared to baseline were all significant (p = 0.002 and p = 0.003, respectively, for main effects), confirming our mainhypothesis. Furthermore, Pearson’s correlation of OBN with QIDS-SR (5 weeks) was specific compared to perceptual dimensions ofthe ASC (p < 0.05).Discussion: This repo
Carhart-Harris RL, Bolstridge M, Day CMJ, et al., 2017, Psilocybin with psychological support for treatment-resistant depression: six-month follow-up, Psychopharmacology, Vol: 235, Pages: 399-408, ISSN: 0033-3158
RATIONALE: Recent clinical trials are reporting marked improvements in mental health outcomes with psychedelic drug-assisted psychotherapy. OBJECTIVES: Here, we report on safety and efficacy outcomes for up to 6 months in an open-label trial of psilocybin for treatment-resistant depression. METHODS: Twenty patients (six females) with (mostly) severe, unipolar, treatment-resistant major depression received two oral doses of psilocybin (10 and 25 mg, 7 days apart) in a supportive setting. Depressive symptoms were assessed from 1 week to 6 months post-treatment, with the self-rated QIDS-SR16 as the primary outcome measure. RESULTS: Treatment was generally well tolerated. Relative to baseline, marked reductions in depressive symptoms were observed for the first 5 weeks post-treatment (Cohen's d = 2.2 at week 1 and 2.3 at week 5, both p < 0.001); nine and four patients met the criteria for response and remission at week 5. Results remained positive at 3 and 6 months (Cohen's d = 1.5 and 1.4, respectively, both p < 0.001). No patients sought conventional antidepressant treatment within 5 weeks of psilocybin. Reductions in depressive symptoms at 5 weeks were predicted by the quality of the acute psychedelic experience. CONCLUSIONS: Although limited conclusions can be drawn about treatment efficacy from open-label trials, tolerability was good, effect sizes large and symptom improvements appeared rapidly after just two psilocybin treatment sessions and remained significant 6 months post-treatment in a treatment-resistant cohort. Psilocybin represents a promising paradigm for unresponsive depression that warrants further research in double-blind randomised control trials.
Stroud JB, Freeman TP, Leech R, et al., 2017, Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression, Psychopharmacology, Vol: 235, Pages: 459-466, ISSN: 0033-3158
RATIONALE: Depressed patients robustly exhibit affective biases in emotional processing which are altered by SSRIs and predict clinical outcome. OBJECTIVES: The objective of this study is to investigate whether psilocybin, recently shown to rapidly improve mood in treatment-resistant depression (TRD), alters patients' emotional processing biases. METHODS: Seventeen patients with treatment-resistant depression completed a dynamic emotional face recognition task at baseline and 1 month later after two doses of psilocybin with psychological support. Sixteen controls completed the emotional recognition task over the same time frame but did not receive psilocybin. RESULTS: We found evidence for a group × time interaction on speed of emotion recognition (p = .035). At baseline, patients were slower at recognising facial emotions compared with controls (p < .001). After psilocybin, this difference was remediated (p = .208). Emotion recognition was faster at follow-up compared with baseline in patients (p = .004, d = .876) but not controls (p = .263, d = .302). In patients, this change was significantly correlated with a reduction in anhedonia over the same time period (r = .640, p = .010). CONCLUSIONS: Psilocybin with psychological support appears to improve processing of emotional faces in treatment-resistant depression, and this correlates with reduced anhedonia. Placebo-controlled studies are warranted to follow up these preliminary findings.
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
Psilocybin with psychological support is showing promise as a treatment model in psychiatry but its therapeutic mechanisms are poorly understood. Here, cerebral blood flow (CBF) and blood oxygen-level dependent (BOLD) resting-state functional connectivity (RSFC) were measured with functional magnetic resonance imaging (fMRI) before and after treatment with psilocybin (serotonin agonist) for treatment-resistant depression (TRD). Quality pre and post treatment fMRI data were collected from 16 of 19 patients. Decreased depressive symptoms were observed in all 19 patients at 1-week post-treatment and 47% met criteria for response at 5 weeks. Whole-brain analyses revealed post-treatment decreases in CBF in the temporal cortex, including the amygdala. Decreased amygdala CBF correlated with reduced depressive symptoms. Focusing on a priori selected circuitry for RSFC analyses, increased RSFC was observed within the default-mode network (DMN) post-treatment. Increased ventromedial prefrontal cortex-bilateral inferior lateral parietal cortex RSFC was predictive of treatment response at 5-weeks, as was decreased parahippocampal-prefrontal cortex RSFC. These data fill an important knowledge gap regarding the post-treatment brain effects of psilocybin, and are the first in depressed patients. The post-treatment brain changes are different to previously observed acute effects of psilocybin and other ‘psychedelics’ yet were related to clinical outcomes. A ‘reset’ therapeutic mechanism is proposed.
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
Nutt D, 2016, Psilocybin for anxiety and depression in cancer care? Lessons from the past and prospects for the future, JOURNAL OF PSYCHOPHARMACOLOGY, Vol: 30, Pages: 1163-1164, ISSN: 0269-8811
Carhart-Harris RL, Nutt DJ, 2016, Question-based Drug Development for psilocybin Reply, LANCET PSYCHIATRY, Vol: 3, Pages: 807-807, ISSN: 2215-0374
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
Lysergic acid diethylamide (LSD) is a classic psychedelic drug that alters cognition in a characteristic way. It has been suggested that psychedelics expand the breadth of cognition via actions on the central nervous system. Previous work has shown changes in semantic processing under psilocybin (a related psychedelic to LSD) that are consistent with an increased spread of semantic activation. The present study investigates this further using a picture-naming task and the psychedelic, LSD. Ten participants completed the task under placebo and LSD. Results revealed significant effects of LSD on accuracy and error correction that were consistent with an increased spread of semantic activation under LSD. These results are consistent with a generalised “entropic” effect on the mind. We suggest incorporating direct neuroimaging measures in future studies, and to employ more naturalistic measures of semantic processing that may enhance ecological validity.
Carhart-Harris RL, Bolstridge M, Rucker J, et al., 2016, Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study, The Lancet Psychiatry, Vol: 3, Pages: 619-627, ISSN: 2215-0366
BACKGROUND: Psilocybin is a serotonin receptor agonist that occurs naturally in some mushroom species. Recent studies have assessed the therapeutic potential of psilocybin for various conditions, including end-of-life anxiety, obsessive-compulsive disorder, and smoking and alcohol dependence, with promising preliminary results. Here, we aimed to investigate the feasibility, safety, and efficacy of psilocybin in patients with unipolar treatment-resistant depression. METHODS: In this open-label feasibility trial, 12 patients (six men, six women) with moderate-to-severe, unipolar, treatment-resistant major depression received two oral doses of psilocybin (10 mg and 25 mg, 7 days apart) in a supportive setting. There was no control group. Psychological support was provided before, during, and after each session. The primary outcome measure for feasibility was patient-reported intensity of psilocybin's effects. Patients were monitored for adverse reactions during the dosing sessions and subsequent clinic and remote follow-up. Depressive symptoms were assessed with standard assessments from 1 week to 3 months after treatment, with the 16-item Quick Inventory of Depressive Symptoms (QIDS) serving as the primary efficacy outcome. This trial is registered with ISRCTN, number ISRCTN14426797. FINDINGS: Psilocybin's acute psychedelic effects typically became detectable 30-60 min after dosing, peaked 2-3 h after dosing, and subsided to negligible levels at least 6 h after dosing. Mean self-rated intensity (on a 0-1 scale) was 0·51 (SD 0·36) for the low-dose session and 0·75 (SD 0·27) for the high-dose session. Psilocybin was well tolerated by all of the patients, and no serious or unexpected adverse events occurred. The adverse reactions we noted were transient anxiety during drug onset (all patients), transient confusion or thought disorder (nine patients), mild and transient nausea (four patients), and transient headache (four patients). Relative to
Lebedev AV, Lövdén M, Rosenthal G, et al., 2015, Finding the self by losing the self: Neural correlates of ego-dissolution under psilocybin., Human Brain Mapping, ISSN: 1097-0193
Ego-disturbances have been a topic in schizophrenia research since the earliest clinical descriptions of the disorder. Manifesting as a feeling that one's "self," "ego," or "I" is disintegrating or that the border between one's self and the external world is dissolving, "ego-disintegration" or "dissolution" is also an important feature of the psychedelic experience, such as is produced by psilocybin (a compound found in "magic mushrooms"). Fifteen healthy subjects took part in this placebo-controlled study. Twelve-minute functional MRI scans were acquired on two occasions: subjects received an intravenous infusion of saline on one occasion (placebo) and 2 mg psilocybin on the other. Twenty-two visual analogue scale ratings were completed soon after scanning and the first principal component of these, dominated by items referring to "ego-dissolution", was used as a primary measure of interest in subsequent analyses. Employing methods of connectivity analysis and graph theory, an association was found between psilocybin-induced ego-dissolution and decreased functional connectivity between the medial temporal lobe and high-level cortical regions. Ego-dissolution was also associated with a "disintegration" of the salience network and reduced interhemispheric communication. Addressing baseline brain dynamics as a predictor of drug-response, individuals with lower diversity of executive network nodes were more likely to experience ego-dissolution under psilocybin. These results implicate MTL-cortical decoupling, decreased salience network integrity, and reduced inter-hemispheric communication in psilocybin-induced ego disturbance and suggest that the maintenance of "self"or "ego," as a perceptual phenomenon, may rest on the normal functioning of these systems. Hum Brain Mapp, 2015. © 2015 Wiley Periodicals, Inc.
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