Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function

Brain serotonin 2A receptor binding predicts subjective temporal and mystical effects of psilocybin in healthy humans

BACKGROUND

Psilocybin is a serotonergic psychedelic with psychoactive effects mediated by serotonin 2A receptor (5-HT2AR) activation. It produces an acute psychedelic altered state of consciousness with a unique phenomenology that can be temporally characterized by three intensity phases: onset of psychoactive effect, a peak plateau and return to normal consciousness.

AIMS

We evaluated whether pre-drug brain 5-HT2AR binding predicted the three phases of psilocybin subjective drug intensity (SDI) and retrospective self-report of mystical type experiences in healthy individuals.

METHOD

Sixteen participants completed a pre-drug [¹¹C]Cimbi-36 positron emission tomography scan to assess 5-HT2AR binding. On a separate day, participants completed a single psilocybin session (oral dose range 0.2-0.3 mg/kg), during which SDI was assessed every 20 min. The Mystical Experience Questionnaire (MEQ) was completed at the end of the session. The three SDI phases were modelled using segmented linear regressions. We evaluated the associations between neocortex 5-HT2AR binding and SDI/MEQ outcomes using linear regression models.

RESULTS

Neocortex 5-HT2AR was statistically significantly negatively associated with peak plateau duration and positively with time to return to normal waking consciousness. It was also statistically significantly negatively associated with MEQ total score.

CONCLUSION

This is the first study to investigate how individual brain 5-HT2AR binding predicts subjective effects of a single dose of psilocybin. Our findings reinforce the role of cerebral 5-HT2AR in shaping the temporal and mystical features of the psychedelic experience. Future studies should examine whether individual brain levels of 5-HT2AR have an impact on therapeutic outcomes in clinical studies.

Neural Correlates of the Shamanic State of Consciousness

Psychedelics have been recognized as model interventions for studying altered states of consciousness. However, few empirical studies of the shamanic state of consciousness, which is anecdotally similar to the psychedelic state, exist. We investigated the neural correlates of shamanic trance using high-density electroencephalography (EEG) in 24 shamanic practitioners and 24 healthy controls during rest, shamanic drumming, and classical music listening, followed by an assessment of altered states of consciousness. EEG data were used to assess changes in absolute power, connectivity, signal diversity, and criticality, which were correlated with assessment measures. We also compared assessment scores to those of individuals in a previous study under the influence of psychedelics. Shamanic practitioners were significantly different from controls in several domains of altered states of consciousness, with scores comparable to or exceeding that of healthy volunteers under the influence of psychedelics. Practitioners also displayed increased gamma power during drumming that positively correlated with elementary visual alterations. Furthermore, shamanic practitioners had decreased low alpha and increased low beta connectivity during drumming and classical music and decreased neural signal diversity in the gamma band during drumming that inversely correlated with insightfulness. Finally, criticality in practitioners was increased during drumming in the low and high beta and gamma bands, with increases in the low beta band correlating with complex imagery and elementary visual alterations. These findings suggest that psychedelic drug-induced and non-pharmacologic alterations in consciousness have overlapping phenomenal traits but are distinct states of consciousness, as reflected by the unique brain-related changes during shamanic trance compared to previous literature investigating the psychedelic state.

Combining Psychedelic and Mindfulness Interventions: Synergies to Inform Clinical Practice

Psychedelic and mindfulness interventions have been shown to improve mental ill-health and wellbeing, with a range of clinical processes and effects in common. However, each appear to contain specific challenges in the context of mental health treatment. In this Perspective, we focus on a set of distinct affordances, "useful differences", within psychedelic and mindfulness interventions that might address common challenges within the other intervention. Accordingly, we propose a set of applied synergies, indicating specific ways in which these two promising interventions might be combined for greater benefit. Metaphorically, on the journey toward mental health and wellbeing, we propose that psychedelic treatments may serve the role of Compass (initiating, motivating, and steering the course of mindfulness practice), with mindfulness interventions serving the role of Vehicle (integrating, deepening, generalizing, and maintaining the novel perspectives and motivation instigated by psychedelic experience). We outline a set of testable hypotheses and future research associated with the synergistic action of psychedelic and mindfulness interventions toward improved clinical outcomes.

Psychedelic Harm Reduction and Integration: A Transtheoretical Model for Clinical Practice

Psychedelic Harm Reduction and Integration (PHRI) is a transtheoretical and transdiagnostic clinical approach to working with patients who are using or considering using psychedelics in any context. The ongoing discussion of psychedelics in academic research and mainstream media, coupled with recent law enforcement deprioritization of psychedelics and compassionate use approvals for psychedelic-assisted therapy, make this model exceedingly timely. Given the prevalence of psychedelic use, the therapeutic potential of psychedelics, and the unique cultural and historical context in which psychedelics are placed, it is important that mental health providers have an understanding of the unique motivations, experiences, and needs of people who use them. PHRI incorporates elements of harm reduction psychotherapy and psychedelic-assisted psychotherapy, and can be applied in both brief and ongoing psychotherapy interactions. PHRI represents a shift away from assessment limited to untoward outcomes of psychedelic use and abstinence-based addiction treatment paradigms and toward a stance of compassionate, destigmatizing acceptance of patients' choices. Considerations for assessment, preparation, and working with difficult experiences are presented.

LSD alters dynamic integration and segregation in the human brain

Investigating changes in brain function induced by mind-altering substances such as LSD is a powerful method for interrogating and understanding how mind interfaces with brain, by connecting novel psychological phenomena with their neurobiological correlates. LSD is known to increase measures of brain complexity, potentially reflecting a neurobiological correlate of the especially rich phenomenological content of psychedelic-induced experiences. Yet although the subjective stream of consciousness is a constant ebb and flow, no studies to date have investigated how LSD influences the dynamics of functional connectivity in the human brain. Focusing on the two fundamental network properties of integration and segregation, here we combined graph theory and dynamic functional connectivity from resting-state functional MRI to examine time-resolved effects of LSD on brain networks properties and subjective experiences. Our main finding is that the effects of LSD on brain function and subjective experience are non-uniform in time: LSD makes globally segregated sub-states of dynamic functional connectivity more complex, and weakens the relationship between functional and anatomical connectivity. On a regional level, LSD reduces functional connectivity of the anterior medial prefrontal cortex, specifically during states of high segregation. Time-specific effects were correlated with different aspects of subjective experiences; in particular, ego dissolution was predicted by increased small-world organisation during a state of high global integration. These results reveal a more nuanced, temporally-specific picture of altered brain connectivity and complexity under psychedelics than has previously been reported.

Hazy memories in the courtroom: A review of alcohol and other drug effects on false memory and suggestibility

Alcohol and other psychoactive drugs are oftentimes implicated in legal cases. A pertinent question herein is whether such substances might adversely affect testimonies of victims, eyewitnesses, or suspects by propelling the formation of false memory and increasing susceptibility to suggestion. In the current review, we amassed all available evidence on the effects of intoxication on false memory formation and suggestibility, including the substances alcohol, benzodiazepines, cannabis, stimulants, hallucinogens, and antipsychotics. Our review indicated that alcohol and cannabis under certain conditions increased the susceptibility to false memories and/or suggestion with effect sizes ranging from medium to large. When intoxicated during an event, alcohol is most likely to increase this susceptibility at high intoxication levels or after a delay, whereas cannabis exerts detrimental effects during acute intoxication but not necessarily once sober. For other substances, ecologically valid research separating different memory phases is needed. Overall, differences between substances regarding false memory effects exist, suggesting that a nuanced approach is needed when dealing with intoxicated individuals in a legal context.

Trends in the Top-Cited Articles on Classic Psychedelics

This study was designed to identify trends in the top-cited classic psychedelic publications. The top 50 publications on classic psychedelics with the greatest total of number of citations and annual citation rate were identified and pooled. Unique articles (n = 77) were dichotomized by median year of publication (2010); the differential distribution of study characteristics between the "Recent Cohort" (n = 40) and "Older Cohort" (n = 37) were documented. The Recent Cohort had a greater annual citation rate (median 76.5, IQR 43.8 to 103.3) compared to the Older Cohort (median 8.8, IQR 4.2 to 17.2, p < .001). The Recent Cohort included a greater number of clinical studies (n = 27 [67.5%] vs. n = 10 [27.0%]) while the Older Cohort included more basic science and preclinical studies (n = 22 [59.5%] vs. n = 3 [7.5%], p < .001). Psilocybin was the predominant psychedelic studied in the Recent Cohort (n = 26 [40.6%] vs. n = 8 [17.4%]) while lysergic acid diethylamide (LSD) was predominantly studied in the Older Cohort (n = 26 [56.5%] vs. n = 19 [29.7%], p = .028). The Recent Cohort included more studies examining affective disorders (n = 16 [25.8%] vs. n = 1 [2.7%]) and substance use disorders (n = 6 [9.7%] vs. n = 1 [2.7%]), while the Older Cohort included a greater number of pharmacological outcomes (n = 26 [70.3%] vs. n = 11 [17.7%], p < .001). This study identified and documented trends in the top-cited classic psychedelic publications. The field is continuing to form a foundational understanding of the pharmacological effects of psychedelics and is now advancing with the identification of therapeutic uses within clinical populations.

Classic serotonergic psychedelics for mood and depressive symptoms: a meta-analysis of mood disorder patients and healthy participants

RATIONALE

Major depressive disorder is one of the leading global causes of disability, for which the classic serotonergic psychedelics have recently reemerged as a potential therapeutic treatment option.

OBJECTIVE

We present the first meta-analytic review evaluating the clinical effects of classic serotonergic psychedelics vs placebo for mood state and symptoms of depression in both healthy and clinical populations (separately).

RESULTS

Our search revealed 12 eligible studies (n = 257; 124 healthy participants, and 133 patients with mood disorders), with data from randomized controlled trials involving psilocybin (n = 8), lysergic acid diethylamide ([LSD]; n = 3), and ayahuasca (n = 1). The meta-analyses of acute mood outcomes (3 h to 1 day after treatment) for healthy volunteers and patients revealed improvements with moderate significant effect sizes in favor of psychedelics, as well as for the longer-term (16 to 60 days after treatments) mood state of patients. For patients with mood disorder, significant effect sizes were detected on the acute, medium (2-7 days after treatment), and longer-term outcomes favoring psychedelics on the reduction of depressive symptoms.

CONCLUSION

Despite the concerns over unblinding and expectancy, the strength of the effect sizes, fast onset, and enduring therapeutic effects of these psychotherapeutic agents encourage further double-blind, placebo-controlled clinical trials assessing them for management of negative mood and depressive symptoms.

Cellular Uptake of Psychostimulants - Are High- and Low-Affinity Organic Cation Transporters Drug Traffickers?

Psychostimulants are used therapeutically and for illegal recreational purposes. Many of these are inhibitors of the presynaptic noradrenaline, dopamine, and serotonin transporters (NET, DAT, and SERT). According to their physicochemical properties, some might also be substrates of polyspecific organic cation transporters (OCTs) that mediate uptake in liver and kidneys for metabolism and excretion. OCT1 is genetically highly polymorphic, with strong effects on transporter activity and expression. To study potential interindividual differences in their pharmacokinetics, 18 psychostimulants and hallucinogens were assessed in vitro for transport by different OCTs as well as by the high-affinity monoamine transporters NET, DAT, and SERT. The hallucinogenic natural compound mescaline was found to be strongly transported by wild-type OCT1 with a K_m of 24.3 µM and a v_max of 642 pmol × mg protein⁻¹ × min⁻¹. Transport was modestly reduced in variants *2 and *7, more strongly reduced in *3 and *4, and lowest in *5 and *6, while *8 showed a moderately increased transport capacity. The other phenylethylamine derivatives methamphetamine, para-methoxymethamphetamine, (-)-ephedrine, and cathine ((+)-norpseudoephedrine), as well as dimethyltryptamine, were substrates of OCT2 with K_m values in the range of 7.9–46.0 µM and v_max values between 70.7 and 570 pmol × mg protein⁻¹ × min⁻¹. Affinities were similar or modestly reduced and the transport capacities were reduced down to half in the naturally occurring variant A270S. Cathine was found to be a substrate for NET and DAT, with the K_m being 21-fold and the v_max 10-fold higher for DAT but still significantly lower compared to OCT2. This study has shown that several psychostimulants and hallucinogens are substrates for OCTs. Given the extensive cellular uptake of mescaline by the genetically highly polymorphic OCT1, strong interindividual variation in the pharmacokinetics of mescaline might be possible, which could be a reason for highly variable adverse reactions. The involvement of the polymorphic OCT2 in the renal excretion of several psychostimulants could be one reason for individual differences in toxicity.

Ketamine and Serotonergic Psychedelics: Common Mechanisms Underlying the Effects of Rapid-Acting Antidepressants

BACKGROUND

The glutamatergic modulator ketamine has created a blueprint for studying novel pharmaceuticals in the field. Recent studies suggest that "classic" serotonergic psychedelics (SPs) may also have antidepressant efficacy. Both ketamine and SPs appear to produce rapid, sustained antidepressant effects after a transient psychoactive period.

METHODS

This review summarizes areas of overlap between SP and ketamine research and considers the possibility of a common, downstream mechanism of action. The therapeutic relevance of the psychoactive state, overlapping cellular and molecular effects, and overlapping electrophysiological and neuroimaging observations are all reviewed.

RESULTS

Taken together, the evidence suggests a potentially shared mechanism wherein both ketamine and SPs may engender rapid neuroplastic effects in a glutamatergic activity-dependent manner. It is postulated that, though distinct, both ketamine and SPs appear to produce acute alterations in cortical network activity that may initially produce psychoactive effects and later produce milder, sustained changes in network efficiency associated with therapeutic response. However, despite some commonalities between the psychoactive component of these pharmacologically distinct therapies-such as engagement of the downstream glutamatergic pathway-the connection between psychoactive impact and antidepressant efficacy remains unclear and requires more rigorous research.

CONCLUSIONS

Rapid-acting antidepressants currently under investigation may share some downstream pharmacological effects, suggesting that their antidepressant effects may come about via related mechanisms. Given the prototypic nature of ketamine research and recent progress in this area, this platform could be used to investigate entirely new classes of antidepressants with rapid and robust actions.

Pharmacotherapeutic Strategies and New Targets in OCD

Effective pharmacological and psychotherapeutic treatments are well established for obsessive-compulsive disorder (OCD). Serotonin reuptake inhibitors (SRIs) are first-line treatment and are of benefit to about half of patients. Augmentation of SRI treatment with low-dose neuroleptics is an evidence-based second-line strategy. Specialty psychotherapy is also used as both first-line and second-line treatment and can benefit many. However, a substantial number of patients do not respond to these treatments. New alternatives are urgently needed. This review summarizes evidence for these established pharmacotherapeutic strategies, and for others that have been investigated in refractory disease but are not supported by the same level of evidence. We focus on three neurotransmitter systems in the brain: serotonin, dopamine, and glutamate. We summarize evidence from genetic, neuroimaging, animal model, and other lines of investigation that probe these three systems in patients with OCD. We also review recent work on predictors of response to current treatments. While many studies suggest abnormalities that may provide insight into the pathophysiology of the disorder, most studies have been small, and non-replication of reported findings has been common. Nevertheless, the gradual accrual of evidence for neurotransmitter dysregulation may in time lead the way to new pharmacological strategies.

Psychedelics in Psychiatry: Neuroplastic, Immunomodulatory, and Neurotransmitter Mechanisms

Mounting evidence suggests safety and efficacy of psychedelic compounds as potential novel therapeutics in psychiatry. Ketamine has been approved by the Food and Drug Administration in a new class of antidepressants, and 3,4-methylenedioxymethamphetamine (MDMA) is undergoing phase III clinical trials for post-traumatic stress disorder. Psilocybin and lysergic acid diethylamide (LSD) are being investigated in several phase II and phase I clinical trials. Hence, the concept of psychedelics as therapeutics may be incorporated into modern society. Here, we discuss the main known neurobiological therapeutic mechanisms of psychedelics, which are thought to be mediated by the effects of these compounds on the serotonergic (via 5-HT2A and 5-HT1A receptors) and glutamatergic [via N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors] systems. We focus on 1) neuroplasticity mediated by the modulation of mammalian target of rapamycin-, brain-derived neurotrophic factor-, and early growth response-related pathways; 2) immunomodulation via effects on the hypothalamic-pituitary-adrenal axis, nuclear factor ĸB, and cytokines such as tumor necrosis factor-α and interleukin 1, 6, and 10 production and release; and 3) modulation of serotonergic, dopaminergic, glutamatergic, GABAergic, and norepinephrinergic receptors, transporters, and turnover systems. We discuss arising concerns and ways to assess potential neurobiological changes, dependence, and immunosuppression. Although larger cohorts are required to corroborate preliminary findings, the results obtained so far are promising and represent a critical opportunity for improvement of pharmacotherapies in psychiatry, an area that has seen limited therapeutic advancement in the last 20 years. Studies are underway that are trying to decouple the psychedelic effects from the therapeutic effects of these compounds. SIGNIFICANCE STATEMENT: Psychedelic compounds are emerging as potential novel therapeutics in psychiatry. However, understanding of molecular mechanisms mediating improvement remains limited. This paper reviews the available evidence concerning the effects of psychedelic compounds on pathways that modulate neuroplasticity, immunity, and neurotransmitter systems. This work aims to be a reference for psychiatrists who may soon be faced with the possibility of prescribing psychedelic compounds as medications, helping them assess which compound(s) and regimen could be most useful for decreasing specific psychiatric symptoms.

Baseline Power of Theta Oscillations Predicts Mystical-Type Experiences Induced by DMT in a Natural Setting

N,N-Dimethyltryptamine (DMT) is a classic psychedelic capable of inducing short-lasting but profound changes in consciousness. As with other psychedelics, the experience induced by DMT strongly depends upon contextual factors, yet the neurobiological determinants of this variability remain unknown. The present study investigated changes in neural oscillations elicited by inhaled DMT, and whether baseline electroencephalography (EEG) recordings could predict the subjective effects reported by the participants. Healthy volunteers (N = 35) were measured with EEG before and during the acute effects of DMT consumed in a natural setting. Source-localized neural oscillations were correlated with the results of multiple questionnaires employed to assess the subjective effects of the drug. DMT resulted in a marked reduction of alpha and beta oscillations, and increased posterior spectral power in the delta, theta and gamma bands. The power of fronto-temporal theta oscillations was inversely correlated with scales indexing feelings of unity and transcendence, which are an integral part of the phenomenology of mystical-type experiences. The robustness of these results was supported using a machine learning model for regression trained and tested following a cross-validation procedure. These results are consistent with the observation that the state of mind prior to consuming a psychedelic drug influences the ensuing subjective experience of the user. They also suggest that baseline EEG screenings before administration of a serotonergic psychedelic could be useful to estimate the likelihood of inducing mystical-type experiences, previously linked to sustained positive effects in well-being and improved outcome of therapeutic interventions.

Consciousness, Religion, and Gurus: Pitfalls of Psychedelic Medicine

This viewpoint identifies pitfalls in the study of psychedelic compounds, including those that pose challenges for the potential use of psychedelics as medicines. They are as follows: (1) Sloppiness regarding use of the term "consciousness". (2) Inappropriate introduction of religious/spiritual beliefs of investigators or clinicians. (3) Clinical boundaries and other ethical challenges associated with psychedelic treatments.

Psilocybin-Assisted Group Therapy and Attachment: Observed Reduction in Attachment Anxiety and Influences of Attachment Insecurity on the Psilocybin Experience

Attachment insecurity is determined early in life, is a risk factor for psychopathology, and can be measured on two separate continuous dimensions: attachment anxiety and attachment avoidance. Therapeutic changes toward more secure attachment correlate with reduction in psychiatric symptoms. Psilocybin-assisted psychotherapy has demonstrated promise in the treatment of psychopathology, such as treatment-resistant depression and substance use disorders. We hypothesized that psilocybin-assisted psychotherapy would reduce attachment anxiety and attachment avoidance, thus increasing attachment security. We also hypothesized that baseline measures of attachment insecurity, which can reflect a diminished capacity for trust and exploration, would inform the quality of the psilocybin session. Participants were male long-term AIDS survivors with moderate-severe demoralization (n = 18). Using the Experiences in Close Relationships scale, we measured attachment insecurity at baseline as well as immediately, and 3 months, after completion of a brief group therapy course, which included a single midtreatment open-label psilocybin session conducted individually. Clinically important aspects of the psilocybin session were assessed using the revised Mystical Experience Questionnaire and the Challenging Experience Questionnaire the day following psilocybin administration. Self-reported ratings of attachment anxiety decreased significantly from baseline to 3-months post-intervention, t(16) = -2.2; p = 0.045; d _rm = 0.45; 95% CI 0.01, 0.87. Attachment avoidance did not change significantly. Baseline attachment anxiety was strongly correlated with psilocybin-occasioned mystical-type experiences, r(15) = 0.53, p = 0.029, and baseline attachment avoidance was strongly correlated with psilocybin-related challenging experiences, r(16) = 0.62, p = 0.006. These findings have important implications for the general treatment of psychopathology as well as optimizing psilocybin-assisted psychotherapy as a broadly applicable treatment modality.

The potential synergistic effects between psychedelic administration and nature contact for the improvement of mental health

Therapeutic psychedelic administration and contact with nature have been associated with the same psychological mechanisms: decreased rumination and negative affect, enhanced psychological connectedness and mindfulness-related capacities, and heightened states of awe and transcendent experiences, all processes linked to improvements in mental health amongst clinical and healthy populations. Nature-based settings can have inherently psychologically soothing properties which may complement all stages of psychedelic therapy (mainly preparation and integration) whilst potentiating increases in nature relatedness, with associated psychological benefits. Maximising enhancement of nature relatedness through therapeutic psychedelic administration may constitute an independent and complementary pathway towards improvements in mental health that can be elicited by psychedelics.

Psychedelic Psychiatry: Preparing for Novel Treatments Involving Altered States of Consciousness

The past decade has seen a renaissance of research interest into the psychotherapeutic potential of psychedelic compounds. In 2019, Oakland and Denver became the first two jurisdictions in the United States to decriminalize the possession of psychedelic-containing organisms. As research and public policy continue to evolve, it becomes increasingly plausible that psychedelics will become viable treatment options for psychiatric conditions. Psychiatrists should be integral to models of psychedelic prescription and patient management. The risk for adverse psychological and medical effects from psychedelic sessions necessitates psychiatric supervision. The literature on psychedelic-assisted psychotherapy may provide wisdom regarding practical aspects of managing patients' treatment sessions.

"Tobacco Is the Chief Medicinal Plant in My Work": Therapeutic Uses of Tobacco in Peruvian Amazonian Medicine Exemplified by the Work of a Maestro Tabaquero

Introduction

Harmful usage of tobacco is a public health problem of global concern and, in many countries, the main risk factor for non-communicable diseases. Yet, in the Peruvian Amazon, the geographical region believed to be tobacco’s historical birthplace, this plant is associated with a strikingly different usage and repute: Tobacco (especially Nicotiana rustica L.) in this area is described as a potent medicinal plant, used topically or via ingestion to treat a variety of health conditions. The goal of this transdisciplinary field study was to investigate clinical applications of the tobacco plant as per Amazonian medicine exemplified in the practice of a reputed Maestro Tabaquero, an Amazonian traditional healer whose medical specialization focuses on tobacco-based treatments.

Methods

Using a transdisciplinary clinical approach, we conducted in-depth interviews with the tabaquero applying the systematizing expert interview method, in order to map modes of preparation and administration, indications, contraindications, effects, risks, adverse effects, and systemic aspects of tobacco-based remedies.

Results

The informant’s descriptions revealed refined knowledge on this plant’s therapeutic properties and scope, safety profile, and application techniques. The main indications mentioned included “problems of the mind,” of the respiratory system, parasitic illnesses (intestinal/skin), gout, and Amazonian epistemic conditions described as spiritual-energetic in nature. A liquid remedy taken orally was his most commonly used preparation, with acute/sub-acute effects involving a pronounced psychoactive component (altered state of consciousness) and physiological response (emesis, nausea). A skilled tabaquero that knows how to dose, administer, and intervene in case of adverse effects was considered imperative for safe treatment delivery.

Conclusions

To our knowledge, this is the first study employing a transdisciplinary clinical approach to examine therapeutic applications of tobacco by an Amazonian tabaquero. Our findings significantly contribute to the growing research literature on Amazonian medicine and emergent psychedelic-assisted therapies and could, in the long-term, open new treatment avenues in several domains. Forthcoming studies should assess toxicity/safety and clinical outcomes of patients receiving Amazonian tobacco-based treatment.

Compassionate use of psychedelics

In the present paper, we discuss the ethics of compassionate psychedelic psychotherapy and argue that it can be morally permissible. When talking about psychedelics, we mean specifically two substances: psilocybin and MDMA. When administered under supportive conditions and in conjunction with psychotherapy, therapies assisted by these substances show promising results. However, given the publicly controversial nature of psychedelics, compassionate psychedelic psychotherapy calls for ethical justification. We thus review the safety and efficacy of psilocybin- and MDMA-assisted therapies and claim that it can be rational for some patients to try psychedelic therapy. We think it can be rational despite the uncertainty of outcomes associated with compassionate use as an unproven treatment regime, as the expected value of psychedelic psychotherapy can be assessed and can outweigh the expected value of routine care, palliative care, or no care at all. Furthermore, we respond to the objection that psychedelic psychotherapy is morally impermissible because it is epistemically harmful. We argue that given the current level of understanding of psychedelics, this objection is unsubstantiated for a number of reasons, but mainly because there is no experimental evidence to suggest that epistemic harm actually takes place.

Psilocybin occasioned mystical-type experiences

OBJECTIVE

Research into psychedelic therapy models has shown promise for the treatment of specific psychiatric conditions. Mystical-type experiences occasioned by psilocybin have been correlated with therapeutic benefits and long-term improvements in positive mental outlook and attitudes. This article aims to provide an overview of the topic, highlight strengths and weaknesses in current research, generate novel perspectives and discussion, and consider future avenues for research.

DESIGN

This narrative review was designed to summarise and assess the state of research on psilocybin occasioned mystical-type experiences and applications for the treatment of specific psychiatric conditions.

RESULTS

Contemporary methods on the quantification of mystical-type experiences and their acute subjective effects are discussed. Recent studies provide some understanding of the pharmacological actions of psychedelics although the neurological similarities and differences between spontaneous and psychedelic mystical-type experiences are not well described. Applicability to modern clinical settings is assessed. Potential novel therapeutic applications include use in positive psychology interventions in healthy individuals.

CONCLUSIONS

Since 2006 significant advancements in understanding the therapeutic potential of psilocybin-assisted psychotherapy have been made; however, more work is required to understand the neuromechanistic processes and applicability in modern clinical settings. Despite promising results in recent studies, funding issues for clinical trials, legal concerns and socio-cultural resistance provide a counterpoint to experimental evidence.

Post-Psychedelic Reductions in Experiential Avoidance Are Associated With Decreases in Depression Severity and Suicidal Ideation

Psychedelic therapy shows promise as a novel intervention for a wide range of mental health concerns but its therapeutic action is incompletely understood. In line with acceptance and commitment therapy's (ACT's) transdiagnostic model, qualitative research has suggested that reductions in experiential avoidance are an important component of therapeutic outcomes associated with psychedelics. However, limited research has quantitatively explored the association between decreases in experiential avoidance and therapeutic outcomes associated with psychedelics. Therefore, in two prospective studies, using convenience samples of individuals with plans to use a psychedelic, we explored the impact of psychedelic use on experiential avoidance, depression severity, and suicidal ideation, as well as relationships between changes in these outcomes. Participants (Study 1, N=104; Study 2, N=254) completed self-report questionnaires of depression severity, suicidal ideation, and experiential avoidance: 1) before using a psychedelic (in ceremonial and non-ceremonial contexts), as well as 2) 2-weeks and 3) 4-weeks after psychedelic use. Across both studies, repeated measures ANOVAs indicated significant decreases in experiential avoidance, depression severity, and suicidal ideation after psychedelic use. Furthermore, decreases in experiential avoidance were significantly associated with decreases in depression severity and suicidal ideation. These results suggest that psychedelics may lead to significant decreases in experiential avoidance, depression severity, and suicidal ideation. Additionally, these findings imply that reduced experiential avoidance may be a transdiagnostic mechanism mediating treatment success within psychedelic therapy. We conclude that integrating psychedelics with psychotherapeutic interventions that target experiential avoidance (e.g. ACT) may enhance therapeutic outcomes.

DMT analogues: N-ethyl-N-propyl-tryptamine and N-allyl-N-methytryptamine as their hydro-fumarate salts

The solid-state structures of the hydro-fumarate salts of two N,N-di-alkyl-tryptamines, namely N-ethyl-N-propyl-tryptammonium (EPT) hydro-fumarate {systematic name: [2-(1H-indol-3-yl)eth-yl](meth-yl)propyl-aza-nium 3-carb-oxy-prop-2-enoate}, C15H23N2 +·C4H3O4 -, and N-allyl-N-methyl-tryptammonium (MALT) hydro-fumarate {systematic name: [2-(1H-indol-3-yl)eth-yl](meth-yl)(prop-2-en-1-yl)aza-nium 3-carb-oxy-prop-2-enoate}, C14H19N2 +·C4H3O4 -, are reported. Both compounds possess a protonated tryptammonium cation, and a hydro-fumarate anion in the asymmetric unit. The ethyl group of the EPT cation is modeled as a two-component disorder with 50% occupancy for each component. In the extended structure, N-H⋯O and O-H⋯O hydrogen bonds generate infinite two-dimensional networks parallel to the (001) plane for both compounds.

Understanding the neurobiological effects of drug abuse: Lessons from zebrafish models

Drug abuse and brain disorders related to drug comsumption are public health problems with harmful individual and social consequences. The identification of therapeutic targets and precise pharmacological treatments to these neuropsychiatric conditions associated with drug abuse are urgently needed. Understanding the link between neurobiological mechanisms and behavior is a key aspect of elucidating drug abuse-related targets. Due to various molecular, biochemical, pharmacological, and physiological features, the zebrafish (Danio rerio) has been considered a suitable vertebrate for modeling complex processes involved in drug abuse responses. In this review, we discuss how the zebrafish has been successfully used for modeling neurobehavioral phenotypes related to drug abuse and review the effects of opioids, cannabinoids, alcohol, nicotine, and psychedelic drugs on the central nervous system (CNS). Moreover, we summarize recent advances in zebrafish-based studies and outline potential advantages and limitations of the existing zebrafish models to explore the neurochemical bases of drug abuse and addiction. Finally, we discuss how the use of zebrafish models may present fruitful approaches to provide valuable clinically translatable data.

Novel harmala-ocudelic tuning (HOT) for ocular disorders

The eye contains serotonin, and possesses serotonergic receptors and modulators. Selective serotonin reuptake inhibitors (SSRIs) may impair ocular function, while other serotonin receptor-binding drugs might improve it. A putative vision-improving drug must be safe at therapeutic doses, most preferably with long-lasting benefits from a single or very few administration(s). One drug potentially satisfying these criteria is the common, botanically-occurring indole alkaloid and "major hallucinogen," harmine. Harmine is prominent in the leaves of the Generally Recognized as Safe (GRAS) Passiflora, and in Peganum and Banisteriopsis, the two preeminent "sacred" medicinal plants of India/pre-Islamic Persia/modern Iran and the Amazon respectively. Though the possibility of drug-drug or herb-drug interactions exists, especially with SSRIs, at correct patient-individualized dosages, these plants, used alone, are minimally hallucinogenic, well tolerated, potentially exerting profound therapeutic effects on vision from a single or few administration(s) lasting months or years. The hypothesized mechanism for this extraordinary action is tuning of the serotonergic receptors in the eye in their binding affinity for serotonin, a putative neurochemical "ocudelic" homologue to the psychedelic phenomenon, likely potentiated, according to clinical experience with classical hallucinogens, by therapeutic music, positive psychological "set," and conducive environmental "setting." Blinded research with harmala alkaloid-containing plants in ocular patients using psychedelic therapy accoutrements, viz. eyeshades, high fidelity classical music, headphones, two guides, pre-dosing preparation, and post-dosing integration, could non-invasively assess visual acuity in presbyopia. Significant results would stimulate further exploration of this novel approach to ocular disorders. Deeper benefit, particularly when the retina is compromised, might follow co-ingestion of the harmala alkaloid-containing plants with plants containing dimethyltryptamine.

Psychedelics and Psychedelic-Assisted Psychotherapy

OBJECTIVE

The authors provide an evidenced-based summary of the literature on the clinical application of psychedelic drugs in psychiatric disorders.

METHODS

Searches of PubMed and PsycINFO via Ovid were conducted for articles in English, in peer-reviewed journals, reporting on "psilocybin," "lysergic acid diethylamide," "LSD," "ayahuasca," "3,4-methylenedioxymethamphetamine," and "MDMA," in human subjects, published between 2007 and July 1, 2019. A total of 1,603 articles were identified and screened. Articles that did not contain the terms "clinical trial," "therapy," or "imaging" in the title or abstract were filtered out. The 161 remaining articles were reviewed by two or more authors. The authors identified 14 articles reporting on well-designed clinical trials investigating the efficacy of lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), psilocybin, and ayahuasca for the treatment of mood and anxiety disorders, trauma and stress-related disorders, and substance-related and addictive disorders as well as in end-of-life care.

RESULTS

The most significant database exists for MDMA and psilocybin, which have been designated by the U.S. Food and Drug Administration (FDA) as "breakthrough therapies" for posttraumatic stress disorder (PTSD) and treatment-resistant depression, respectively. The research on LSD and ayahuasca is observational, but available evidence suggests that these agents may have therapeutic effects in specific psychiatric disorders.

CONCLUSIONS

Randomized clinical trials support the efficacy of MDMA in the treatment of PTSD and psilocybin in the treatment of depression and cancer-related anxiety. The research to support the use of LSD and ayahuasca in the treatment of psychiatric disorders is preliminary, although promising. Overall, the database is insufficient for FDA approval of any psychedelic compound for routine clinical use in psychiatric disorders at this time, but continued research on the efficacy of psychedelics for the treatment of psychiatric disorders is warranted.

Construction, comparison and evolution of networks in life sciences and other disciplines

Network approaches have become pervasive in many research fields. They allow for a more comprehensive understanding of complex relationships between entities as well as their group-level properties and dynamics. Many networks change over time, be it within seconds or millions of years, depending on the nature of the network. Our focus will be on comparative network analyses in life sciences, where deciphering temporal network changes is a core interest of molecular, ecological, neuropsychological and evolutionary biologists. Further, we will take a journey through different disciplines, such as social sciences, finance and computational gastronomy, to present commonalities and differences in how networks change and can be analysed. Finally, we envision how borrowing ideas from these disciplines could enrich the future of life science research.

Prospective examination of synthetic 5-methoxy-N,N-dimethyltryptamine inhalation: effects on salivary IL-6, cortisol levels, affect, and non-judgment

RATIONALE

5-methoxy-N,N-dimethyltryptamine is a psychotropic substance found in various plant and animal species and is synthetically produced. 5-methoxy-N,N-dimethyltryptamine is used in naturalistic settings for spiritual exploration, recreation, or to address negative affect and mood problems. However, scientific knowledge on the effects of 5-methoxy-N,N-dimethyltryptamine in humans is scarce.

OBJECTIVES

The first objective was to assess the effects of inhalation of vaporized synthetic 5-methoxy-N,N-dimethyltryptamine on neuroendocrine markers. The second objective was to assess effects of the substance on affect and mindfulness. In addition, we assessed whether ratings of subjective measures were associated with changes in stress biomarkers (i.e., cortisol) and immune response (i.e., IL-6, CRP, IL-1β), as well as the acute psychedelic experience.

METHODS

Assessments (baseline, immediately post-session, and 7-day follow-up) were made in 11 participants. Salivary samples were collected at baseline and post-session and analyzed by high-sensitivity enzyme-linked immunosorbent assay (ELISA).

RESULTS

5-methoxy-N,N-dimethyltryptamine significantly increased cortisol levels and decreased IL-6 concentrations in saliva immediately post-session. These changes were not correlated to ratings of mental health or the psychedelic experience. Relative to baseline, ratings of non-judgment significantly increased, and ratings of depression decreased immediately post-session and at follow-up. Ratings of anxiety and stress decreased from baseline to 7-day follow-up. Participant ratings of the psychedelic experience correlated negatively with ratings of affect and positively with ratings of non-judgment.

CONCLUSION

Inhalation of vaporized synthetic 5-methoxy-N,N-dimethyltryptamine produced significant changes in inflammatory markers, improved affect, and non-judgment in volunteers. Future research should examine the effect of 5-methoxy-N,N-dimethyltryptamineamine with healthy volunteers in a controlled laboratory setting.

Mystical and Other Alterations in Sense of Self: An Expanded Framework for Studying Nonordinary Experiences

Although many researchers in psychology, religious studies, and psychiatry recognize that there is overlap in the experiences their subjects recount, disciplinary silos and challenges involved in comparing reported experiences have left us with little understanding of the mechanisms, whether biological, psychological, and/or sociocultural, through which these experiences are represented and differentiated. So-called mystical experiences, which some psychologists view as potentially sui generis, provide a test case for assessing whether we can develop an expanded framework for studying unusual experiences across disciplines and cultures. Evidence for the special nature of "mystical experience" rests on the operationalization of a metaphysically untestable construct in two widely used self-report scales: the Mysticism Scale and the Mystical Experiences Questionnaire. Consideration of the construct in light of research on alterations in sense of self induced by psychoactive drugs and meditation practices suggests that "positive experiences of undifferentiated unity" are not sui generis, but rather a type of "ego dissolution." To better understand the nature and effects of unusual experiences, such as alterations in the sense of self, we need self-report measures that distinguish between generically worded experiences and the way they are appraised in terms of valence, significance, cause, and long-term effects in different contexts.

Therapeutic Use of LSD in Psychiatry: A Systematic Review of Randomized-Controlled Clinical Trials

Lysergic acid diethylamide (LSD) was studied from the 1950s to the 1970s to evaluate behavioral and personality changes, as well as remission of psychiatric symptoms in various disorders. LSD was used in the treatment of anxiety, depression, psychosomatic diseases and addiction. However, most of the studies were not performed under contemporary standards, and it has taken several decades for a resurgence of interest in LSD research and its therapeutic potential for psychiatry. The aim of this review is to identify controlled and randomized clinical trials that assess the potential use of LSD in psychiatry. PRISMA guidelines for systematic review were followed. A literature search of PubMed and Psychedelic bibliography from Multidisciplinary Association for Psychedelic Studies (MAPS) databases was performed as well as a manual search of references from evaluated studies. Only randomized-controlled clinical trials were included. Study quality was systematically calculated by using the Cochrane Collaboration Tool for assessing risk of bias. A final selection of 11 articles was made after considering inclusion and exclusion criteria. LSD was administered to 567 patients in a dose ranging from 20 to 800 mcg. Despite the design heterogeneity of clinical trials, positive results were observed, thus revealing the therapeutic potential of LSD to reduce psychiatric symptomatology, mainly in alcoholism. The vast majority of authors describe significant and positive short-term changes in patients, despite the fact that in some studies an important homogenization was observed between the LSD treatment group and control group at long-term follow-up. Multiple variables regarding LSD treatment therapeutic approach and quality of experience were revealed and related to therapeutic outcomes. LSD is revealed as a potential therapeutic agent in psychiatry; the evidence to date is strongest for the use of LSD in the treatment of alcoholism. Despite the difficulty of designing proper double blind clinical trials with this substance, new studies that conform to modern standards are necessary in order to strengthen our knowledge on its use and open new doors in the future.

Using the pharmacy retail model to examine perceptions and biases of a UK population sample towards regulation of specific psychoactive drugs

Background:

Contemporary research indicates that the legal classifications of cannabis (Schedule 2, Class B), 3,4-methylenedioxymethamphetamine (MDMA) (Schedule 1, Class A) and psilocybin (Schedule 1, Class A) in the United Kingdom are not entirely based on considerations of harm and therapeutic utility. The legal classifications of the substances discussed are typically determined by legislators such as Parliament and, therefore, may be a reflection of the views or perceived views of the general public.

Objective:

The aim of the study was to provide an indication of the underlying psychology regarding the legislated sale of alcohol, tobacco, cannabis, MDMA and psilocybin in pharmacies according to a UK general population sample.

Methods:

A sample of 105 UK nationals was selected for the survey. Participants were asked questions on perceived relative harm of the five substances. After viewing contemporary information on reported relative harm and therapeutic applications, the participants were asked questions related to using the pharmacy retail model for the sale of the substances discussed. Participants who opposed the substances being sold primarily in pharmacies were asked to explain their rationale according to a predetermined list of options for each of the five drugs. Participants were also asked whether they consider it a human right to be legally permitted to consume the substances.

Results:

The participants' perceptions of relative harm (tobacco > MDMA > psilocybin > alcohol > cannabis) were not in agreement with the relative harm reported in the literature (alcohol > tobacco > cannabis > MDMA > psilocybin). Principal objections to the currently illicit substances being legally available in pharmacies include it sending the wrong message; it feels wrong; it is too dangerous; disliking the smell of cannabis; disapproval of the people; and not liking the idea of people using psychoactive drugs for entertainment or to have mystical/religious experiences. Overall, the participants determined that being legally permitted to consume the substances discussed is an issue of relevance to human rights. A majority of the male participants concluded that being legally permitted to consume alcohol, tobacco, cannabis and Psilocybe mushrooms is a human right in contrast to the majority of female participants who solely considered alcohol consumption to be a human right.

Conclusions:

The data suggest that the legal classifications may not simply be based on considerations of harm. Misperceptions of the dangers, biases and non-health-related aversions likely contribute to the continuation of policies that do not reflect the state of scientific research.

Accounting for Microdosing Classic Psychedelics

Microdosing classic psychedelics (e.g., LSD [lysergic acid diethylamide] and psilocybin) is the practice of taking small amounts of these substances to bring about various positive life changes. Little is known about the subjective experiences and perceptions of those who engage in the practice. Accordingly, we use the sociology of accounts as a theoretical framework to explore the ways that those who microdose excuse or justify their practice. Using data from semistructured interviews with 30 people who had microdosed, we find that none provided excuses for their microdosing, but all offered one or more justifications. When discussing their microdosing, participants emphasized six key justifications: denial of injury, self-sustaining, self-fulfillment, appeal to normality, appeal to loyalties, and knowledgeableness. Findings provide insights into the subjective experiences of those who microdose, including the ways that they attempt to align their actions with societal expectations.

Novel pharmacological targets in drug development for the treatment of anxiety and anxiety-related disorders

Current medication for anxiety disorders is suboptimal in terms of efficiency and tolerability, highlighting the need for improved drug treatments. In this review an overview of drugs being studied in different phases of clinical trials for their potential in the treatment of fear-, anxiety- and trauma-related disorders is presented. One strategy followed in drug development is refining and improving compounds interacting with existing anxiolytic drug targets, such as serotonergic and prototypical GABAergic benzodiazepines. A more innovative approach involves the search for compounds with novel mechanisms of anxiolytic action using the growing knowledge base concerning the relevant neurocircuitries and neurobiological mechanisms underlying pathological fear and anxiety. The target systems evaluated in clinical trials include glutamate, endocannabinoid and neuropeptide systems, as well as ion channels and targets derived from phytochemicals. Examples of promising novel candidates currently in clinical development for generalised anxiety disorder, social anxiety disorder, panic disorder, obsessive compulsive disorder or post-traumatic stress disorder include ketamine, riluzole, xenon with one common pharmacological action of modulation of glutamatergic neurotransmission, as well as the neurosteroid aloradine. Finally, compounds such as D-cycloserine, MDMA, L-DOPA and cannabinoids have shown efficacy in enhancing fear-extinction learning in humans. They are thus investigated in clinical trials as an augmentative strategy for speeding up and enhancing the long-term effectiveness of exposure-based psychotherapy, which could render chronic anxiolytic drug treatment dispensable for many patients. These efforts are indicative of a rekindled interest and renewed optimism in the anxiety drug discovery field, after decades of relative stagnation.

Narrative identity, rationality, and microdosing classic psychedelics

BACKGROUND

Microdosing involves ingesting a small dose of a classic psychedelic (e.g., LSD and psilocybin) at regular intervals for prolonged periods. The practice is said to reduce anxiety, improve mood, and offer several creative and practical benefits to users. Using the narrative identity theoretical framework, our aim was to explore the experiences of those who microdosed classic psychedelics. Specifically, we sought to understand how and why they began microdosing and how they made sense of their actions in the context of their conventional lives.

METHODS

To understand the experiences of those who microdose classic psychedelics, we rely on data collected from semi-structured interviews with 30 people who had microdosed.

RESULTS

Participants saw themselves as conventional citizens who microdosed for rational and instrumental purposes. They emphasized the rationality of microdosing by discussing (1) the practicality of their procurement and administration processes, (2) the connection between their microdosing practice and their general awareness in health and wellness, and (3) the benefits of the practice.

CONCLUSION

Participants described their microdosing in the context of embracing traditional middle-class values. This created social distance between themselves and those who use drugs recreationally. While people who use drugs recreationally typically construct boundaries by distancing themselves from symbolic others (i.e., "crackheads," "meth heads," "junkies"), microdosers constructed boundaries by emphasizing connections to conventional citizens who embrace middle-class values. This connection to conventional citizens allows them to normalize their drug use and facilitates persistence.

Population Survey Data Informing the Therapeutic Potential of Classic and Novel Phenethylamine, Tryptamine, and Lysergamide Psychedelics

INTRODUCTION

The majority of contemporary psychedelic research has focused on ayahuasca, lysergic acid diethylamide, and psilocybin, though there are hundreds of novel psychedelic compounds that may have clinical utility. The purpose of the present study was to evaluate the therapeutic potential of classic and novel phenethylamine, tryptamine, and lysergamide psychedelics via a large, nationally representative population-based survey.

METHODS

We tested the unique associations of lifetime classic and novel phenethylamine, tryptamine, and lysergamide psychedelics with past month psychological distress and past year suicidality among respondents pooled from years 2008-2017 of the National Survey on Drug Use and Health (weighted N = 260,964,827).

RESULTS

Lifetime classic tryptamine use was associated with a decreased odds of past month psychological distress [aOR = 0.76; (0.69-0.83)] and past year suicidal thinking [aOR = 0.79; (0.72-0.87)]. Lifetime novel phenethylamine use, on the other hand, was associated with an increased odds of past year suicidal thinking [aOR = 1.44; (1.06-1.95)] and past year suicidal planning [aOR = 1.60; (1.06-2.41)]. No other significant associations were found.

DISCUSSION AND CONCLUSIONS

These findings, which may be driven by differences in pharmacodynamics, suggest that classic tryptamines may hold the greatest therapeutic potential of the psychedelics, whereas novel phenethylamines may pose risk for harm. The present findings thus support continued research on the clinical application of classic tryptamines. Though the current results caution against the clinical utility of novel phenethylamines, further study of these and other novel psychedelic substances is nonetheless warranted to better understand their potential application.