OPEN Foundation

R. Carhart-Harris

Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression

Abstract

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.

Stroud, J. B., Freeman, T. P., Leech, R., Hindocha, C., Lawn, W., Nutt, D. J., … & Carhart-Harris, R. L. (2017). Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression. Psychopharmacology, 1-8. 10.1007/s00213-017-4754-y
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Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms

Abstract

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.
Carhart-Harris, R. L., Roseman, L., Bolstridge, M., Demetriou, L., Pannekoek, J. N., Wall, M. B., … & Leech, R. (2017). Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms. Scientific reports7(1), 13187. 10.1038/s41598-017-13282-7
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Serotonin and brain function: a tale of two receptors

Abstract

Previous attempts to identify a unified theory of brain serotonin function have largely failed to achieve consensus. In this present synthesis, we integrate previous perspectives with new and older data to create a novel bipartite model centred on the view that serotonin neurotransmission enhances two distinct adaptive responses to adversity, mediated in large part by its two most prevalent and researched brain receptors: the 5-HT1A and 5-HT2A receptors. We propose that passive coping (i.e. tolerating a source of stress) is mediated by postsynaptic 5-HT1AR signalling and characterised by stress moderation. Conversely, we argue that active coping (i.e. actively addressing a source of stress) is mediated by 5-HT2AR signalling and characterised by enhanced plasticity (defined as capacity for change). We propose that 5-HT1AR-mediated stress moderation may be the brain’s default response to adversity but that an improved ability to change one’s situation and/or relationship to it via 5-HT2AR-mediated plasticity may also be important – and increasingly so as the level of adversity reaches a critical point. We propose that the 5-HT1AR pathway is enhanced by conventional 5-HT reuptake blocking antidepressants such as the selective serotonin reuptake inhibitors (SSRIs), whereas the 5-HT2AR pathway is enhanced by 5-HT2AR-agonist psychedelics. This bipartite model purports to explain how different drugs (SSRIs and psychedelics) that modulate the serotonergic system in different ways, can achieve complementary adaptive and potentially therapeutic outcomes.
Carhart-Harris, R. L., & Nutt, D. J. (2017). Serotonin and brain function: a tale of two receptors. Journal of Psychopharmacology (Oxford, England)31(9), 1091. 10.1177/0269881117725915
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Psychedelics and connectedness

Abstract

Psychedelic drugs are creating ripples in psychiatry as evidence accumulates of their therapeutic potential. An important question remains unresolved however: how are psychedelics effective? We propose that a sense of connectedness is key, provide some preliminary evidence to support this, and suggest a roadmap for testing it further.
Carhart-Harris, R. L., Erritzoe, D., Haijen, E., Kaelen, M., & Watts, R. (2017). Psychedelics and connectedness. Psychopharmacology, 1-4. 10.1007/s00213-017-4701-y
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Patients’ Accounts of Increased “Connectedness” and “Acceptance” After Psilocybin for Treatment-Resistant Depression

Objective:

To identify patients’ perceptions of the value of psilocybin as a treatment for depression.

Method:

Twenty patients enrolled in an open-label trial of psilocybin for treatment-resistant depression participated in a semistructured interview at 6-month follow-up. Thematic analysis was used to identify patients’ experiences of the treatment and how it compared with previous treatments.

Results:

Two main change processes were identified in relation to the treatment. The first concerned change from disconnection (from self, others, and world) to connection, and the second concerned change from avoidance (of emotion) to acceptance. A third theme concerned comparison between psilocybin and conventional treatments. Patients reported that medications and some short-term talking therapies tended to reinforce their sense of disconnection and avoidance, whereas treatment with psilocybin encouraged connection and acceptance.

Conclusion:

These results suggest that psilocybin treatment for depression may work via paradigmatically novel means, antithetical to antidepressant medications, and some short-term talking therapies.
Watts, R., Day, C., Krzanowski, J., Nutt, D., & Carhart-Harris, R. (2017). Patients’ Accounts of Increased “Connectedness” and “Acceptance” After Psilocybin for Treatment-Resistant Depression. Journal of Humanistic Psychology, 0022167817709585.

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The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future

Abstract

Plant-based psychedelics, such as psilocybin, have an ancient history of medicinal use. After the first English language report on LSD in 1950, psychedelics enjoyed a short-lived relationship with psychology and psychiatry. Used most notably as aids to psychotherapy for the treatment of mood disorders and alcohol dependence, drugs such as LSD showed initial therapeutic promise before prohibitive legislature in the mid-1960s effectively ended all major psychedelic research programs. Since the early 1990s, there has been a steady revival of human psychedelic research: last year saw reports on the first modern brain imaging study with LSD and three separate clinical trials of psilocybin for depressive symptoms. In this circumspective piece, RLC-H and GMG share their opinions on the promises and pitfalls of renewed psychedelic research, with a focus on the development of psilocybin as a treatment for depression.
Carhart-Harris, R. L., & Goodwin, G. M. (2017). The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future. Neuropsychopharmacology. 10.1038/npp.2017.84
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Psychedelics, Personality and Political Perspectives

Abstract

The psychedelic experience (including psychedelic-induced ego dissolution) can effect lasting change in a person’s attitudes and beliefs. Here, we aimed to investigate the association between naturalistic psychedelic use and personality, political perspectives, and nature relatedness using an anonymous internet survey. Participants (N = 893) provided information about their naturalistic psychedelic, cocaine, and alcohol use, and answered questions relating to personality traits of openness and conscientiousness (Ten-Item Personality Inventory), nature relatedness (Nature-Relatedness Scale), and political attitudes (one-item liberalism-conservatism measure and five-item libertarian-authoritarian measure). Participants also rated the degree of ego dissolution experienced during their “most intense” recalled psychedelic experience (Ego-Dissolution Inventory). Multivariate linear regression analysis indicated that lifetime psychedelic use (but not lifetime cocaine use or weekly alcohol consumption) positively predicted liberal political views, openness and nature relatedness, and negatively predicted authoritarian political views, after accounting for potential confounding variables. Ego dissolution experienced during a participant’s “most intense” psychedelic experience positively predicted liberal political views, openness and nature relatedness, and negatively predicted authoritarian political views. Further work is needed to investigate the nature of the relationship between the peak psychedelic experience and openness to new experiences, egalitarian political views, and concern for the environment.

Nour, M. M., Evans, L., & Carhart-Harris, R. L. (2017). Psychedelics, Personality and Political Perspectives. Journal of Psychoactive Drugs, 1-10. 10.1080/02791072.2017.1312643
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Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin

Abstract

What is the level of consciousness of the psychedelic state? Empirically, measures of neural signal diversity such as entropy and Lempel-Ziv (LZ) complexity score higher for wakeful rest than for states with lower conscious level like propofol-induced anesthesia. Here we compute these measures for spontaneous magnetoencephalographic (MEG) signals from humans during altered states of consciousness induced by three psychedelic substances: psilocybin, ketamine and LSD. For all three, we find reliably higher spontaneous signal diversity, even when controlling for spectral changes. This increase is most pronounced for the single-channel LZ complexity measure, and hence for temporal, as opposed to spatial, signal diversity. We also uncover selective correlations between changes in signal diversity and phenomenological reports of the intensity of psychedelic experience. This is the first time that these measures have been applied to the psychedelic state and, crucially, that they have yielded values exceeding those of normal waking consciousness. These findings suggest that the sustained occurrence of psychedelic phenomenology constitutes an elevated level of consciousness – as measured by neural signal diversity.
Schartner, M. M., Carhart-Harris, R. L., Barrett, A. B., Seth, A. K., & Muthukumaraswamy, S. D. (2017). Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin. Scientific Reports, 7. 10.1038/srep46421
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Psychedelics and the science of self-experience

Abstract

Altered self-experiences arise in certain psychiatric conditions, and may be induced by psychoactive drugs and spiritual/religious practices. Recently, a neuroscience of self-experience has begun to crystallise, drawing upon findings from functional neuroimaging and altered states of consciousness occasioned by psychedelic drugs. This advance may be of great importance for psychiatry.

Nour, M. M., & Carhart-Harris, R. L. (2017). Psychedelics and the science of self-experience. 10.1192/bjp.bp.116.194738
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Altered Insula Connectivity Under MDMA

Abstract

Recent work with noninvasive human brain imaging has started to investigate the effects of 3, 4-methylenedioxymethamphetamine (MDMA) on large-scale patterns of brain activity. MDMA, a potent monoamine-releaser with particularly pronounced serotonin- releasing properties, has unique subjective effects that include: marked positive mood, pleasant/unusual bodily sensations and pro-social, empathic feelings. However, the neurobiological basis for these effects is not properly understood, and the present analysis sought to address this knowledge gap. To do this, we administered MDMA-HCl (100 mg p.o.) and, separately, placebo (ascorbic acid) in a randomized, double-blind, repeated-measures design with twenty-five healthy volunteers undergoing fMRI scanning. We then employed a measure of global resting-state functional brain connectivity and follow-up seed-to-voxel analysis to the fMRI data we acquired. Results revealed decreased right insula/salience network functional connectivity under MDMA. Furthermore, these decreases in right insula/salience network connectivity correlated with baseline trait anxiety and acute experiences of altered bodily sensations under MDMA. The present findings highlight insular disintegration (ie, compromised salience network membership) as a neurobiological signature of the MDMA experience, and relate this brain effect to trait anxiety and acutely altered bodily sensations-both of which are known to be associated with insular functioning.

Walpola, I. C., Nest, T., Roseman, L., Erritzoe, D., Feilding, A., Nutt, D. J., & Carhart-Harris, R. L. (2017). Altered Insula Connectivity Under MDMA. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology. 10.1038/npp.2017.35
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