← Monthly Recaps· September 2021

Psychedelics Research Recap September 2021

Published October 1, 2021

September brought us nearly 30 new and exciting papers on psychedelics that we’ve added to the database. Some focus on the safety of psychedelics, showing the relative safety of LSD in clinical use for instance. Well-being after the ceremonial or therapeutic use of psychedelics and ego-dissolution as a possible mechanism is also explored.

We also learned more about the action of the atypical psychedelic salvinorin-A and get (re)introduced to 2C-X compounds. The use of ‘magic mushrooms’ in the US population is explored and we learn how open psychologists are to psychedelic-assisted therapies. This and much more in our September 2021 psychedelic research recap.

You can find all the papers in our database, and the ones that weren’t added in our September Link Overview.

Psychedelic use differences between the clinic and general population

People in the United States use psilocybin-containing mushrooms to self medicate for reasons related to mental health, with users reporting significantly higher levels of anxiety and depression, and lower quality of life than the average. This finding stands in direct contrast to the narrative that psychedelics lead to more positive mental health outcomes, though there are many confounding factors if we only look at a snapshot in a survey (e.g. those with mental health issues are more likely to try psychedelics).

This is also found when another survey looked at the use of MDMA in those with PTSD and substance use disorder (SUD). It was found that SUD patients with PTSD were more likely to use MDMA than those without PTSD and MDMA use was associated with avoidance symptoms. The authors conclude that MDMA use might reflect an attempt to self-medicate to deal with avoidance symptoms however, it may also be the case that MDMA use led to more severe avoidance symptoms.

The use of psychedelics, without the container of therapy, can be more unpredictable and less therapeutic. In contrast to the two above articles, a review finds that MDMA-assisted therapy could help treat the symptoms of social anxiety disorder (SAD). Disruptions in neurological, perceptual, receptive, and expressive systems regulating social behavior in SAD may take place as a result of MDMA-assisted therapy.

Using psychedelics outside of clinical settings can be challenging as 23 ‘underground’ practitioners report on the unique challenges faced in that context. The interview study reports on the themes identified that range from descriptive (e.g. use of touch) and prescriptive (e.g. grounding) ethical challenges. With recent revelations coming out against some practitioners, the substantial challenges also faced by patients should not be underestimated.

Psychedelics lead to ego dissolution

If you’ve been reading about psychedelics for a bit, you might have come across the term ‘ego dissolution‘. Also called ‘ego death’ the term stands for the complete loss of subjective self-identity, the lack of feeling like a ‘self’ or ‘I’. A theory-building article tackles this subject head-on and argues that although these selfless states of consciousness are rare, they reveal normally congruent processes of self-modelling which demonstrate the principle that phenomenal models of the self ‘shape’ the subjectivity of our experiences.

How this actually happens in the brain is further investigated in a pre-print article that finds that 5-HT2A receptor (the serotonin receptor psychedelics are so fond of) agonism, at the top of the cortical hierarchy, leads to both ego dissolution and long-term neural plasticity. Whether this plasticity may be used to lead to positive mental health outcomes is further investigated in a novel framework that proposes psychedelics may reopen “critical periods” in neurodevelopment whereby the brain is particularly sensitive (neuroplasticity) to environmental input.

Psychedelics can lead us to focus less on the outward-focused aspects of self (identity) and this effect was mediated by ego dissolution (and the intensity of mystical experiences) finds a survey study. The participants in the study also reported higher positive emotional reactivity.

Psychedelics disturb the stability of thought and conscious experience (e.g. dissolving the idea of an ego), and a recent review argues that we should also study this in specific regions of the brain (versus whole-brain models). In doing so, we may get a better grip on which area of the brain ‘generates’ different parts of conscious experience.

Well-being after different psychedelics

An open-label study with 30 participants looked at the improvements in well-being, healthy functioning (in society), depression, and suicidality ratings. Although a quarter of the participants did report healthy well-being, the effect was smaller than that on scores of depression and suicidality. Changes on those two domains may be necessary yet not sufficient for restoration to well-being.

A week after an ayahuasca ceremony, participants reported increased well-being, cognitive empathy, and less neuroticism. A single serving of ayahuasca was found to have these positive effects in an observational study. The study also found an enhanced ability to take an objective and non-judging stance towards the self (decentering), harkening back to the ego dissolution papers profiled above. As with many studies with ayahuasca, this study was done at a ceremony, with a new protocol on freeze-drying ayahuasca, we may be closer to also studying it in clinical settings.

Integrating psychedelic experiences is, as far as we now know, vital for positive outcomes. This perspective is confirmed by ayahuasca ceremony leaders who were interviewed about their views on preparation, integration, and what could go wrong in those processes. Another group that will have a large impact on the well-being of those using psychedelics are psychologists. A survey among them found cautious optimistic attitudes towards psychedelics as medicines.

The rest of the studies in September 2021

A case study from 1959 where psilocybin was used in the treatment of anorexia has recently been translated. Imperial College London is currently recruiting patients for the first modern study of psilocybin-assisted therapy for anorexia.

Multiple review articles have taken a look at the existing literature and conclude that 1) serotonergic psychedelics appear to be effective and safe in improving symptoms of anxiety and depression, and 2) that we have relatively sparse data on neuropsychological function after psychedelics use, especially for psilocybin.

A number of synthetic psychoactive drugs, such as the 2C-family, show activity on the serotonin receptor 5-HT7R (in mice), prompting the authors to argue that this could be a potential target for treating autism. This is in contrast to, as detailed in a meta-analysis of brain imaging studies, to 5-HT1a/2a receptor activity observed with most psychedelics.

Another area where psychedelics show promise is in the treatment of neurodegenerative disorders (e.g. Alzheimer’s). Psychedelics may act as modulators of the immune system by reducing levels of pro-inflammatory biomarkers.

Finally, a hypothesis paper argues for four factors that may have contributed to (early) humans including psychedelics in their diet: 1) management of psychological distress, 2) enhanced social interactions, 3) facilitation of collective rituals, and 4) enhanced group decision making.

Papers Published in September 2021

29 studies from the Blossom database published this month.

Perspectives on psychedelic treatment and research in eating disorders: a web-based questionnaire study of people with eating disorders

Journal of Integrative Neuroscience· Sep 30, 2021· Harding, F., Seynaeve, M., Keeler, J. et al.

In a web-based survey of 200 people with eating disorders, 70% had used complementary treatments and most regarded psychedelic research as worthwhile despite moderate concerns. Participants emphasised the need for education and professional endorsement, plus a safe, monitored setting and strong patient–therapist rapport to address those concerns and support future trials.

Novel Treatment Approaches for Substance Use Disorders: Therapeutic Use of Psychedelics and the Role of Psychotherapy

Current Addiction Reports· Sep 29, 2021· Johnson, M. W., Gründer, G., Betzler, F. et al.

This review (2022) explores how psychedelics can be used to treat substance use disorders (SUDs) Specifically, the authors discuss the role of different forms of psychotherapy such as psychodynamic and cognitive behavioural.

Psychedelics, sociality, and human evolution

Frontiers in Psychology· Sep 29, 2021· Rodríguez Arce, J. M., Winkelman, M. J.

This hypothesis paper (2021) puts forward evidence for a model of the co-evolution and advantages to the consumption of psychedelics by humans in pre-history. Four factors may have contributed to the inclusion of psychedelics in their diet: 1) management of psychological distress, 2) enhanced social interactions, 3) facilitation of collective rituals, and 4) enhanced group decision making.

Self-reported PTSD is associated with increased use of MDMA in adolescents with substance use disorders

European Journal of Psychotraumatology· Sep 28, 2021· Basedow, L. A., Kuitunen-Paul, S., Wiedmann, M. F. et al.

This survey study (n=121) explored the co-occurrence of PTSD in patients with a substance use disorder (SUD). It was found that SUD patients with PTSD were more likely to use MDMA than those without PTSD and MDMA use was associated with avoidance symptoms. The authors conclude that MDMA use might reflect an attempt to self-medicate to deal with avoidance symptoms however, it may also be the case that MDMA use led to more severe avoidance symptoms.

MDMA-Assisted Therapy as a Means to Alter Affective, Cognitive, Behavioral, and Neurological Systems Underlying Social Dysfunction in Social Anxiety Disorder

Frontiers in Psychiatry· Sep 27, 2021· Luoma, J. B., Lear, M. K.

This review (2021) explores the potential of MDMA-assisted therapy for treating the various symptoms of social anxiety disorder (SAD). The authors hypothesize how disruptions in neurological, perceptual, receptive, and expressive systems regulating social behavior in SAD may take place as a result of MDMA-assisted therapy, thereby acting as a stimulus for further research.

Psychedelic mushrooms in the USA: Knowledge, patterns of use and association with health outcomes

MedRvix· Sep 22, 2021· Matzopoulos, R., Morlock, A., Morlock, R. et al.

In a nationally representative US online survey (Nov 2020–Mar 2021), adults reporting psychedelic mushroom use—often to self-treat general mental health—had worse mental-health indicators (higher anxiety and depression scores and lower mental-quality-of-life), were less likely to have health insurance, yet used more healthcare services than non-users. The authors highlight this mismatch with positive media and clinical narratives and call for research into drivers of self‑medication and a national harm‑reduction strategy.

Ibogaine Blocks Cue- and Drug-Induced Reinstatement of Conditioned Place Preference to Ethanol in Male Mice

Frontiers in Pharmacology· Sep 21, 2021· Henriques, G. M., Anjos-Santos, A., Rodrigues, I. R. et al.

In male mice, repeated oral ibogaine (10 or 30 mg/kg) did not produce conditioned place preference but blocked both cue‑ and drug‑induced reinstatement of ethanol‑conditioned place preference in priming‑injection and context‑re‑exposure tests. This indicates ibogaine at non‑rewarding doses may reduce relapse‑like alcohol seeking and warrants consideration as a potential treatment for alcohol use disorder.

Critical Period Plasticity as a Framework for Psychedelic-Assisted Psychotherapy

Frontiers in Neuroscience· Sep 20, 2021· Yehuda, R., Lepow, L., Morishita, H.

The paper proposes a critical-period framework for psychedelic‑assisted psychotherapy, hypothesising that psychedelics transiently remove brakes on adult neuroplasticity to create a development‑like state during which psychotherapeutic and environmental input can produce enduring clinical change. It argues that ocular dominance plasticity in the visual system offers a tractable model for identifying the biological ingredients of such critical periods and for translating those insights to limbic circuits relevant to psychiatric disorders.

Prefrontal contributions to the stability and variability of thought and conscious experience

Neuropsychopharmacology· Sep 20, 2021· Zamani, A., Carhart-Harris, R. L., Christoff, K.

This review (2021) examines how the prefrontal cortex and other brain networks influence the variability and stability of mental phenomena, such as executive functions, mind-wandering, and psychedelic experiences. Specifically, they highlight how different brain networks contribute to these dynamics in the short and long term while acknowledging that the stability of conscious experiences are also contingent upon the stability or variability of the internal and external environments. Since most research on psychedelics has mostly focussed on investigating large-scale brain networks, the authors conclude that future research should also study how specific regions contribute to the variability and stability of conscious experiences depending on their functional specialization.

The kappa opioid receptor and the sleep of reason: Cortico-subcortical imbalance following salvinorin-A

International Journal of Neuropsychopharmacology· Sep 19, 2021· Ona, G., Sampedro, F., Romero, S. et al.

Acute administration of salvinorin-A, a highly selective kappa opioid receptor agonist, produced dramatic dissociative psychotomimetic effects without dysphoria and revealed a cortico–subcortical imbalance. Neurophysiologically this was reflected by widespread cortical hypoperfusion and reduced cortical EEG alpha (with increased delta and gamma) alongside increased blood flow in medial temporal regions (amygdala, hippocampal gyrus) and the cerebellum.

Ayahuasca Lyophilization (Freeze-drying) Protocol with Pre- and Post-procedure Alkaloids Quantification

Journal of Psychoactive Drugs· Sep 17, 2021· Daldegan-Bueno, D., Favaro, V. M., Tófoli, L.F. et al.

This methodological paper (2021) describes a standardized protocol for freeze-drying ayahuasca and compares its alkaloid composition before and after the procedure.

A Qualitative Exploration of Relational Ethical Challenges and Practices in Psychedelic Healing

Journal of Humanistic Psychology· Sep 16, 2021· Brennan, W., Jackson, M. A., MacLean, K. A.

Interviewing 23 practitioners who administered MDMA or psilocybin in underground contexts, the study identifies distinctive relational ethical challenges—such as client nudity, use of non‑sexual touch, and expectations that therapists must have their own psychedelic experiences—and organises these into descriptive themes. It also outlines prescriptive themes (supervision, boundary‑setting, staying within one’s competence) and discusses implications for training and regulation as psychedelic therapies move toward clinical approval.

Neuropsychological Functioning in Users of Serotonergic Psychedelics - A Systematic Review and Meta-Analysis

Frontiers in Pharmacology· Sep 16, 2021· Basedow, L. A., Riemer, T. G., Reiche, S. et al.

This review paper (2021) investigated the persisting effects of psychedelics on neuropsychological function. There is relatively little reliable data on neuropsychological consequences of psychedelics, especially studies with psilocybin (now most commonly used in trials) are lacking.

Do Psychedelics Change Beliefs?

Psyarxiv· Sep 15, 2021· McGovern, H., Leptourgos, P., Hutchinson, B. et al.

The review argues that psychedelics rarely induce wholly new beliefs but instead alter how affective states and social suggestions shape the attribution and updating of beliefs, with individuals’ baseline beliefs moderating both acute and long-term effects. The authors emphasise that these mechanisms must be tested empirically if psychedelics are to be harnessed safely and effectively in clinical and wellbeing contexts.

Assessing the effects of methodological differences on outcomes in the use of psychedelics in the treatment of anxiety and depressive disorders: A systematic review and meta-analysis

Journal of Psychopharmacology· Sep 14, 2021· Leger, R. F., Unterwald, E. M.

This systematic review and meta-analysis of nine clinical trials found that psilocybin, ayahuasca and LSD produced large, rapid and sustained reductions in anxiety (Cohen’s d = 1.26) and depression (Cohen’s d = 1.38) with no serious adverse reactions reported. Methodological differences in agent type did not significantly affect outcomes, but trials using multiple dosing sessions showed significantly greater efficacy than single‑session protocols.

Discovery of G Protein-Biased Antagonists against 5-HT7R

Journal of Medicinal Chemistry· Sep 14, 2021· Lee, H., Lee, J., Kim, D. et al.

This mouse study explored the effects of a number of synthetic psychoactive drugs, such as the 2C-family, on the serotonin receptor 5-HT7R. The ability of a particular 2C compound to bind 5-HT7R over other subtypes and reduce self-grooming time in mice suggests that 5-HT7R could be a potential target for treating autism.

Safety pharmacology of acute LSD administration in healthy subjects

Psychopharmacology· Sep 13, 2021· Holze, F., Caluori, T. V., Vizeli, P. et al.

This pooled analysis (n=83) finds that LSD (25-200 µg) is physiologically and psychologically safe in healthy subjects when administrated in a controlled research setting.

The effects of tryptamine psychedelics in the brain: a meta-analysis of functional and review of molecular imaging studies

Frontiers in Pharmacology· Sep 7, 2021· Castelhano, J. M., Lima, G. M., Teixeira, M. et al.

This meta-analysis (2021) of brain imaging studies finds that under the influence of psychedelics (tryptamines), the most changes in connectivity are indeed the ones where there are the most 5-HT1a/2a receptors. Other regions are also highlighted, and these regions most influenced are responsible for mental imagery, theory of mind, and affective regulation.

LSD-stimulated behaviors in mice require β-arrestin 2 but not β-arrestin 1

Scientific Reports· Sep 3, 2021· Rodriguiz, R. M., Nadkarni, V., Means, C. R. et al.

This mice study finds that, using mice with specific receptor deficiencies, the signals are β-arrestin-2 (βArr; type of protein important in signalling) mediated, but not βarr1 mediated. This line of evidence points towards the requirement of βArr2 for LSD's psychedelic effects.

“Meeting the Medicine Halfway”: Ayahuasca Ceremony Leaders’ Perspectives on Preparation and Integration Practices for Participants

Journal of Humanistic Psychology· Sep 2, 2021· Callon, C., Williams, M., Lafrance, A.

In a qualitative study of 15 ayahuasca ceremony leaders, the authors identify the practices these leaders view as important for promoting safe and productive ceremonial experiences. Key themes were facilitative factors for preparation (participant honesty, readiness and resources), complementary modalities aiding preparation and integration (psychotherapy, spiritual/contemplative practices and creative expression), and integration processes (sharing experiences and working with insights), alongside recognition of ineffective integration practices.

Attitudes and Beliefs about the Therapeutic Use of Psychedelic Drugs among Psychologists in the United States

Journal of Psychoactive Drugs· Sep 1, 2021· Davis, A. K., Agin-Liebes, G. I., España, M. et al.

This survey study (n=366) among clinical psychologists finds cautious optimistic attitudes towards psychedelics as medicines. Most psychologists indicate that they lack education or knowledge of effectiveness surrounding treatments with psychedelics.

Consciousness in active inference: Deep self-models, other minds, and the challenge of psychedelic-induced ego-dissolution

Neuroscience of Consciousness· Sep 1, 2021· Deane, G.

The paper argues that phenomenal consciousness can be explained within predictive processing via active inference as ‘subjective valuation’—a deep inference about the precision of self‑evidencing outcomes instantiated in deep self‑models—and that this framework can guide attributions of experience to other systems through sensory‑attenuation mechanisms. It further contends that psychedelic‑induced ego‑dissolution does not undermine this account but rather corroborates subjective valuation as constitutive of experience and highlights psychedelic research’s value for consciousness science and computational psychiatry.

Improving cognitive functioning in major depressive disorder with psychedelics: a dimensional approach

Neurobiology of Learning and Memory· Sep 1, 2021· Kuiperes, Z., Schreiber, R.

This theory-building literature review (2021) proposes a model that explains how psychedelics can reduce the negativity bias in depressed patients according to Research Domain Criteria (RDoC), a framework that investigates the underlying neurobiology of clinical symptoms across multiple levels of explanation. It is proposed that psychedelics improve depressive symptoms via a similar mechanism as the antidepressant vortioxetine, by stimulating neuroplasticity in the prefrontal cortex and the hippocampus, and decreasing negativity bias through the restoration of deficits in pattern separation.

LSD degrades hippocampal spatial representations and suppresses hippocampal-visual cortical interactions

Cell Reports· Sep 1, 2021· Domenico, C., Haggerty, D., Mou, X. et al.

This rat study investigated the neural correlates of LSD-induced abnormal perceptions while animals navigated a familiar track. It finds that LSD suppresses hippocampal-cortical interactions and degrades internal spatial representations, isolating them from external sensory input, which may underlie the phenomenon of hallucinations.

Neurocognitive aspects of ketamine and esketamine on subjects with treatment-resistant depression: A comparative, randomized and double-blind study

Psychiatry Research· Sep 1, 2021· Araújo-de-Freitas, L., Santos-Lima, C., Mendonça-Filho, E. et al.

This randomised, double-blind, placebo-controlled study (n=54) finds that both esketamine and (racemic) ketamine improve cognition immediately and up to 7 days later for those suffering from depression (TRD). There were virtually no differences between both subgroups. The study found improvements in executive functions, processing speed, and more.

Nitrous oxide as an adjunctive therapy in major depressive disorder: a randomized controlled double-blind pilot trial

brazilian Journal of Psychiatry· Sep 1, 2021· Guimarães, M. C., Guimarães, T. M., Hallak, J. E. et al.

This double-blind placebo-controlled between-subjects study (n=23) tested the antidepressant efficacy of inhaled nitrous oxide (50% N2O|50% O2 versus 100% O2) in patients diagnosed with major depression (MDD). Across multiple treatment sessions administered across a period of 4 weeks, there were significant reductions in depressive symptoms in the acute response to treatment and accumulatively across sessions.

Psilocybin-induced changes in brain network integrity and segregation correlate with plasma psilocin level and psychedelic experience

European Neuropsychopharmacology· Sep 1, 2021· Madsen, M. K., Stenbaek, D. S., Arvidsson, A. et al.

This fMRI study (n=15) investigated the effects of psilocybin (14-21mg/70kg) on the brain and found that the higher the psilocin (active metabolite of psilocybin) and subjective drug experience (SDI) correlated with lower network integrity and segregation (less top-down, more bottom-up).

Spiritual experiences in psychedelic-assisted psychotherapy: Case reports of communion with the divine, the departed, and saints in research using psilocybin for the treatment of alcohol dependence

Spirituality in Clinical Practice· Sep 1, 2021· Podrebarac, S. K., O'donnell, K. C., Mennenga, S. E. et al.

This paper (n=3) presents case studies of experiences with the divine in an ongoing clinical trial at NYU exploring the effects of psilocybin on alcohol dependence.

Visitors of the Dutch drug checking services: Profile and drug use experience

International Journal of Drug Policy· Sep 1, 2021· Koning, R., Benschop, A., Wijffels, C. et al.

This survey study (n=1530) examined the demographic profiles of people who made use of drug checking services in the Netherlands in 2018 and found that most participants who acquired this service had longstanding experience and a higher lifetime prevalence of using ecstasy/MDMA than the average Dutch citizen.