Survey of entity encounter experiences occasioned by inhaled N,N-dimethyltryptamine: Phenomenology, interpretation, and enduring effects

Essentials of Informed Consent to Psychedelic Medicine

Importance

Interest in administering psychedelic agents as mental health treatment is growing rapidly. As drugmakers invest in developing psychedelic medicines for several psychiatric indications, lawmakers are enacting legal reforms to speed access globally, and health agencies are preparing to approve these treatments. Meanwhile, US states, such as Oregon and Colorado, are making psychedelics available for supervised use outside the conventional health care system.

Observations

Despite legal change and potentially imminent regulatory approval in some countries, standards for integrating psychedelics into health care have lagged, including norms for designing and implementing informed consent processes. Informed consent is complicated by the unique features of psychedelics and their means of administration. Because no governments have approved any classic psychedelics for general medical or psychiatric use, only clinical researchers have obtained informed consent from trial participants. Accordingly, there is an unmet need for informed consent processes tailored to the challenges of administering psychedelics in nonresearch settings.

Conclusions and Relevance

Analysis of the challenges of designing and implementing psychedelic informed consent practices revealed 7 essential components, including the possibility of short- and long-term perceptual disturbances, potential personality changes and altered metaphysical beliefs, the limited role of reassuring physical touch, the potential for patient abuse or coercion, the role and risks of data collection, relevant practitioner disclosures, and interactive patient education and comprehension assessment. Because publicly available informed consent documents for psychedelic clinical trials often overlook or underemphasize these essential elements, sample language and procedures to fill the gap are proposed.

Psychological and physiological effects of extended DMT

N,N-Dimethyltryptamine (DMT) is a serotonergic psychedelic that induces a rapid and transient altered state of consciousness when inhaled or injected via bolus administration. Its marked and novel subjective effects make DMT a powerful tool for the neuroscientific study of consciousness and preliminary results show its potential role in treating mental health conditions. In a within-subjects, placebo-controlled study, we investigated a novel method of DMT administration involving a bolus injection paired with a constant-rate infusion, with the goal of extending the DMT experience. Pharmacokinetic parameters of DMT estimated from plasma data of a previous study of bolus intravenous DMT were used to derive dose regimens necessary to keep subjects in steady levels of immersion into the DMT experience over an extended period of 30 min, and four dose regimens consisting of a bolus loading dose and a slow-rate infusion were tested in eleven healthy volunteers (seven male, four female, mean age ± SD = 37.09 ± 8.93 years). The present method is effective for extending the DMT experience in a stable and tolerable fashion. While subjective effects were maintained over the period of active infusion, anxiety ratings remained low and heart rate habituated within 15 min, indicating psychological and physiological safety of extended DMT. Plasma DMT concentrations increased consistently starting 10 min into DMT administration, whereas psychological effects plateaued into the desired steady state, suggesting the development of acute psychological tolerance to DMT. Taken together, these findings demonstrate the safety and effectiveness of continuous IV DMT administration, laying the groundwork for the further development of this method of administration for basic and clinical research.

Religion and the brain: Jordan Grafman's contributions to religion and brain research and the special case of religious language

Grafman and colleagues' papers in religion and brain research have documented the extent to which religious beliefs and behaviors are mediated by standard social cognitive networks in brain. Grafman's work however also points beyond treatments of religious cognition as merely a species of more general social cognitive processes. Data emerging from experiments targeting mystical states as well as reports of encounters with supernatural agents during controlled experiments with psychedelics, suggest that brain mediation of mystical encounters with supernatural agents involves both disruption/downregulation of social cognitive networks and activation of an additional as yet only partially identified neural process suggesting that a full neuroscience account of religious beliefs, behaviors and experiences must extend beyond treatment of religion as an ordinary social process.

Epidemiology of classic psychedelic substances: results from a Norwegian internet convenience sample

Objective

In recent years, there has been a renewed interest in investigating the use of classic psychedelics such as psilocybin and lysergic acid diethylamide (LSD) in the treatment of mental disorders and substance use disorders. However, knowledge about the epidemiology of classic psychedelics in the Nordic countries is limited.

Methods

We recruited adult, Norwegian participants who have had a memorable experience after taking a classic psychedelic substance. They filled in an anonymous internet survey with 119 items covering matters related to recreational use of psychedelics using a secure, web-based application. Data are presented by using descriptive statistics (frequencies, means, and standard deviations).

Results

We recruited 841 participants, 770 (72% male; 88% 45 years or younger) of which were included in the data analysis. The intentions behind taking the psychedelic substance were mainly recreational (46.1%) or therapeutic (42.3%). Most participants reported that their most memorable experience was with psilocybin. As in modern era clinical trials, most participants were well-prepared before, did processing during, and did integration work after the experience, whereas only a minority were supported by a therapist. Self-perceived symptoms of various mental disorders and substance use disorders were prevalent in the sample. Most subjects reported improvements in their condition. Although adverse reactions were usually mild and short-lived, 4.2% lasted for 1 year or more. Persisting flashbacks were present for a year or more among 2.9% of the participants.

Conclusion

In this cross-sectional sample of Norwegian, self-selecting adults, we shed light on what characterizes the most memorable experience with a classic psychedelic substance, including short- and long-term risks and benefits. For the most part, the psychedelic experience led to improvements in self-perceived symptoms of mental disorders and substance use disorders. However, a small subset experienced persisting adverse reactions.

Mystical and Affective Aspects of Psychedelic Use in a Naturalistic Setting: A Linguistic Analysis of Online Experience Reports

Analyzing online retrospective experience reports of psychedelic use can provide valuable insight into their acute subjective effects. Such reports are unexplored in relation to mystical states, which are thought to be a therapeutic mechanism within psychedelic-assisted psychotherapy. We created a set of words that, when encountered in an experience report, indicate the occurrence of mystical elements within the experience. We used the Shroomery.org website to retrieve 7317 publicly available retrospective psychedelic experience reports of psychedelic use, primarily of psilocybin, and have a designated experience intensity level self-assessed by the text authors during submission of the report. We counted the mystical language words using Linguistic Inquiry and Word Count (LIWC) software and additionally performed sentiment analysis of all reports. We found that the occurrence of mystical language grew with increased self-reported experience intensity. We also found that negative sentiment increased, and positive sentiment decreased as self-reported psychedelic experience intensity increased. These two findings raise the question of whether mystical experiences can co-exist with challenging elements within the psychedelic experience, a consideration for future qualitative studies. We present a new mystical language dictionary measure for further use and expansion, with some suggestions on how it can be used in future studies.

Acute Subjective Effects of Psychedelics within and Beyond WEIRD Contexts

Reports of psychedelic experiences may contain similarities and differences across cultural contexts, but most current characterizations and quantifications of psychedelic experiences come from Western medical and naturalistic settings. In this article, we begin with a brief history of the diversity of psychedelic use in non-Western settings. We then compare and contrast accounts of psychedelic experiences within and beyond Western, educated, industrialized, rich, and democratic (WEIRD) contexts. We focus on specific reports of direct testimony of the acute subjective effects of psychedelics experienced across these contexts. We compare themes from each of these various contexts, with special emphasis on psychometric measures such as the mystical experiences questionnaire (MEQ), the five-dimensional altered states of consciousness (5D-ASC) scale, the Survey of God Encounters, and the Survey of Entity Encounters, the Challenging Experiences Questionnaire, and the Inventory of Nonordinary Experiences (INOE). Finally, we offer recommendations for future research to quantify these similarities and differences across cultures to assess them empirically in the future.

Translation and Initial Psychometric Evaluation of Spanish Versions of Three Psychedelic Acute Effects Measures: Mystical, Challenging, and Insight Experiences

This study translated and tested the psychometric properties of acute psychedelic effects measures among Spanish-speaking people. The Psychological Insight Questionnaire (PIQ), Challenging Experiences Questionnaire (CEQ), and Mystical Experiences Questionnaire (MEQ) were translated before being incorporated into a web-based survey. We recruited native Spanish-speakers (N = 442; M_age = 30.8, SD = 10.9; Latino/Latina = 62%; Hispanic = 91.4%; male = 71.5%) to assess their previous experience with one of two psychedelics (LSD = 58.4%; Psilocybin = 41.6%) and their acute and enduring effects. Confirmatory factor analysis (confirming factor structure based on the English version) revealed a good fit for the MEQ, PIQ and the CEQ. Repeating our analysis in each drug subsample revealed consistency in factor structure for each assessment tool. Construct validity was supported by significant positive associations between the PIQ and MEQ, and between the PIQ and MEQ and changes in cognitive fusion and negative associations between changes in prosocial behaviors. As a signal of predictive validity, persisting effects (PEQ) were strongly related to scores on the MEQ and PIQ. Findings demonstrate that the Spanish versions of these measures can be reliably employed in studies of psychedelic use or administration in Spanish-speaking populations.

N, N-Dimethyltryptamine (DMT)-Occasioned Familiarity and the Sense of Familiarity Questionnaire (SOF-Q)

This study investigated the sense of familiarity attributed to N, N-dimethyltryptamine (DMT) experiences. 227 naturalistic inhaled-DMT experiences reporting a sense of familiarity were included. No experiences referenced a previous DMT or psychedelic experience as the source of the familiarity. A high prevalence of concomitant features discordant from ordinary consciousness were identified: features of a mystical experience (97.4%), ego-dissolution (16.3%), and a "profound experience of death" (11.0%). The Sense of Familiarity Questionnaire (SOF-Q) was developed assessing 19 features of familiarity across 5 themes: (1) Familiarity with the Feeling, Emotion, or Knowledge Gained; (2) Familiarity with the Place, Space, State, or Environment; (3) Familiarity with the Act of Going Through the Experience; (4) Familiarity with Transcendent Features; and (5) Familiarity Imparted by an Entity Encounter. Bayesian latent class modeling yielded two stable classes of participants who shared similar SOF-Q responses. Class 1 participants responded, "yes" more often for items within "Familiarity Imparted by an Entity Encounter" and "Familiarity with the Feeling, Emotion, or Knowledge Gained." Results catalogued features of the sense of familiarity imparted by DMT, which appears to be non-referential to a previous psychedelic experience. Findings provide insights into the unique and enigmatic familiarity reported during DMT experiences and offer a foundation for further exploration into this intriguing phenomenon.

Assessing potential of psilocybin for depressive disorders

INTRODUCTION

There has been increasing interest in the role psilocybin may play in the treatment of depressive disorders. Several clinical trials have shown psilocybin to have efficacy in reducing symptoms of depression.

AREASCOVERED

We discuss the current understanding of psilocybin's therapeutic mechanism of action and review existing clinical data investigating psilocybin as a novel therapeutic agent for the treatment of depression.

EXPERT OPINION

There is still much unknown regarding the risks of psilocybin treatment. When weighing the known risks and benefits of psilocybin treatment against those found in existing standards of care, among patients with depression, patients with treatment-resistant depression (TRD) may be the most suitable candidates for psilocybin treatment at this time.

An encounter with the self: A thematic and content analysis of the DMT experience from a naturalistic field study

Introduction

N,N-Dimethyltryptamine (DMT) is an endogenous serotonergic psychedelic capable of producing radical shifts in an experience that have significant implications for consciousness and its neural correlates, especially given the “disconnected consciousness” suggested by the “breakthrough” DMT state. Its increasing usage and clinical trial indicate the growing importance of a thorough elucidation of the experience's qualitative content, over and above the phenomenological structure. This is particularly in light of the intensely pervasive effects of DMT occasions in all dimensions of the self, which are often ontologically challenging yet potentially transformative.

Methods

This is the second report on the first naturalistic field study of DMT use exploring its qualitative analysis. Screened, healthy, anonymized, and experienced DMT users were observed during their non-clinical use of the drug at home (40–75-mg inhaled). In-depth semi-structured interviews, inspired by the micro-phenomenological technique, were employed immediately after their experience. This study reports on the thematic and content analysis of one major domain of the breakthrough experiences elicited, the “self”; where analyses of the “other” were previously reported. A total of 36 post-DMT experience interviews with mostly Caucasian (83%) men (eight women) of a mean of 37 years were predominantly inductively coded.

Results

Invariably, profound and highly intense experiences occurred. The first overarching category comprised the onset of effects, encompassing super-ordinate themes including sensory, emotion and body, and space-time shifts; the second category comprised bodily effects, encompassing themes including pleasurable, neutral/both, and uncomfortable; the third category comprised the sensorial effects, encompassing open-eye, visual, and cross-modal and other; the fourth comprised the psychological effects, encompassing memory and language, awareness and sense of self, and time distortions; and the fifth comprised the emotional effects, encompassing positive, neither/both, and challenging experiences. Many further subthemes also illuminate the rich content of the DMT experience.

Discussion

The present study provides a systematic and nuanced analysis of the content of the breakthrough DMT state pertaining to one's personal and self-referential experiences of the body, senses, psychology, and emotions. The resonances both with previous DMT studies and other types of extraordinary experiences, such as the alien abduction, shamanic and near-death experiences, are also elaborated upon. Putative neural mechanisms and their promise as a psychotherapeutic agent, especially owing to deep emotional impact, are discussed.

Reduced death anxiety as a mediator of the relationship between acute subjective effects of psychedelics and improved subjective well-being

Research over the past several decades suggests that meaningful psychedelic experiences can engender long-term effects on subjective wellbeing. However, less research has investigated the psychological mechanisms through which these effects may emerge. In the present study, participants (N = 201) completed an online survey that retrospectively measured the acute effects of a meaningful psychedelic experience, as well as changes in subjective well-being and death anxiety. Reductions in death anxiety significantly mediated the effects of mystical experience on satisfaction with life, positive affect, and negative affect. Reductions in death anxiety did not mediate any of the effects of psychological insight. Although correlational, the findings are consistent with the hypothesis that some of the benefits of psychedelic-induced mystical experiences on subjective well-being may emerge due to reductions in death anxiety. Nevertheless, further research is needed to establish a causal effect of reduced death anxiety on well-being in the context of psychedelic experiences.

Belief changes associated with psychedelic use

BACKGROUND

Psychedelic use is anecdotally associated with belief changes, although few studies have tested these claims.

AIM

Characterize a broad range of psychedelic occasioned belief changes.

SURVEY

A survey was conducted in 2374 respondents who endorsed having had a belief changing psychedelic experience. Participants rated their agreement with belief statements Before and After the psychedelic experience as well as at the time of survey administration.

RESULTS

Factor analysis of 45 belief statements revealed five factors: "Dualism," "Paranormal/Spirituality," "Non-mammal consciousness," "Mammal consciousness," and "Superstition." Medium to large effect sizes from Before to After the experience were observed for increases in beliefs in "Dualism" (β = 0.72), "Paranormal/Spirituality" (β = 0.90), "Non-mammal consciousness" (β = 0.72), and "Mammal consciousness" (β = 0.74). In contrast, negligible changes were observed for "Superstition" (β = -0.18).). At the individual item level, increases in non-physicalist beliefs included belief in reincarnation, communication with the dead, existence of consciousness after death, telepathy, and consciousness of inanimate natural objects (e.g., rocks). The percentage of participants who identified as a "Believer (e.g., in Ultimate Reality, Higher Power, and/or God, etc.)" increased from 29% Before to 59% After." At both the factor and individual item level, higher ratings of mystical experience were associated with greater changes in beliefs. Belief changes assessed after the experience (an average 8.4 years) remained largely unchanged at the time of survey.

CONCLUSIONS

A single psychedelic experience increased a range of non-physicalist beliefs as well as beliefs about consciousness, meaning, and purpose. Further, the magnitude of belief change is associated with qualitative features of the experience.

The content of complex psychedelic experiences resulting from inhalation of N,N-dimethyltryptamine

Aim

This study examines narratives describing complex psychedelic experiences after smoking N,N-dimethyltryptamine.

Methods

The narrative accounts examined here were gathered from a variety of online sites and analyzed in order to discover themes, categories and patterns in the phenomenon of the resulting psychedelic experiences.

Results

Subjects reported seeing complex and unusual visual and synesthetic phenomena, leaving this world and entering into extraordinary places, encounters with a variety of strange entities, interactions with unusual objects and a wide variety of powerful feelings. The general categories of Places, Objects, Entities and Feelings were found in the phenomena experienced by people who smoked N,N-Dimethyltryptamine. These provided a framework within which more detailed subcategories were found and the range of most frequent to least frequent experiences were identified.

Discussion

While DMT experiences are commonly described by people smoking N,N-dimethyltryptamine as indescribable, unique to everyone and taking place in a single domain called Hyperspace or the Hyperdimension, this research found distinct subcategories of frequently visited Places as well as frequently encountered Entities, Objects and Feelings. From these a more comprehensive understanding can be developed of the unusual and profound experiences resulting from inhalation of N,N,-Dimethyltryptamine.

Understanding subjective experience in psychedelic-assisted psychotherapy: The need for phenomenology

Psychedelic-assisted psychotherapy is being investigated as a treatment for a range of psychiatric illnesses. Current research suggests that the kinds of subjective experiences induced by psychedelic compounds play key roles in producing therapeutic outcomes. To date, most knowledge of therapeutic psychedelic experiences are derived from psychometric assessments with scales such as the Mystical Experience Questionnaire. While these approaches are insightful, more nuanced and detailed descriptions of psychedelic-induced changes to subjective experience are required. Drawing on recent advancements in qualitative methods arising from the interdisciplinary field of phenomenological psychopathology, we propose a systematic and comprehensive investigation into how psychedelic-assisted psychotherapy alters subjective experience. This research programme aims to characterise the nature of therapeutic psychedelic experiences by drawing on concepts from philosophical phenomenology. Such characterisations should, moreover, contribute to our understanding of the mechanisms of psychedelic therapy, the role of integration therapy, and related philosophical debates.

Comparison of psychedelic and near-death or other non-ordinary experiences in changing attitudes about death and dying

Both psychedelic drug experiences and near-death experiences can occasion changes in perspectives on death and dying, but there have been few direct comparisons of these phenomena. This study directly compared psychedelic occasioned and non-drug experiences which altered individuals’ beliefs about death. Individuals who reported an experience that altered their beliefs about death occasioned by either a psychedelic drug or a near-death or other non-ordinary experience completed an online survey. Circumstances of the experience, mystical and near-death subjective features, changes in attitudes about death, and other persisting effects were evaluated. The study sample (n = 3192) included five groups: non-drug near-death or other non-ordinary experiences (n = 933), and drug experiences occasioned by lysergic acid diethylamide (LSD) (n = 904), psilocybin (n = 766), ayahuasca (n = 282), or N,N-dimethyltryptamine (DMT) (n = 307). Analyses of differences in experiences were adjusted statistically for demographic differences between groups. Compared to the psychedelic groups, the non-drug group was more likely to report being unconscious, clinically dead, and that their life was in imminent danger. The groups were remarkably similar in the reported changes in death attitudes attributed to the experience, including a reduced fear of death and high ratings of positive persisting effects and personal meaning, spiritual significance, and psychological insight. Although both psychedelic and non-drug participants showed robust increases on standardized measures of mystical and near-death experiences, these measures were significantly greater in the psychedelic participants. Non-drug participants were more likely to rate their experiences as the single most meaningful of their lives. Comparing across psychedelic substances, ayahuasca and DMT groups tended report stronger and more positive enduring consequences of the experience than the psilocybin and LSD groups, which were largely indistinguishable. These data provide a detailed characterization and comparison of psychedelic occasioned and non-drug experiences that changed attitudes about death and suggest the importance of future prospective psychedelic administration studies.

Pharmacological, neural, and psychological mechanisms underlying psychedelics: A critical review

This paper provides a critical review of several possible mechanisms at different levels of analysis underlying the effects and therapeutic potential of psychedelics. At the (1) biochemical level, psychedelics primarily affect the 5-HT_2A receptor, increase neuroplasticity, offer a critical period for social reward learning, and have anti-inflammatory properties. At the (2) neural level, psychedelics have been associated with reduced efficacy of thalamo-cortical filtering, the loosening of top-down predictive signaling and an increased sensitivity to bottom-up prediction errors, and activation of the claustro-cortical-circuit. At the (3) psychological level, psychedelics have been shown to induce altered and affective states, they affect cognition, induce belief change, exert social effects, and can result in lasting changes in behavior. We outline the potential for a unifying account of the mechanisms underlying psychedelics and contrast this with a model of pluralistic causation. Ultimately, a better understanding of the specific mechanisms underlying the effects of psychedelics could allow for a more targeted therapeutic approach. We highlight current challenges for psychedelic research and provide a research agenda to foster insight in the causal-mechanistic pathways underlying the efficacy of psychedelic research and therapy.

Secular Mysticism

How a positive naturalist understanding of mystical experiences is possible and how these experiences and accompanying practices can be incorporated into a secular mysticism are discussed. Philosophical issues related to such a secular mysticism are also raised: is a truly secular mysticism possible? Are mystical experiences cognitive of transcendent non-natural realities? Can secular mysticism address the issue of the possible construction of mystical experiences? Can one find meaning or a purpose to life when non-natural realities and life after death are not parts of the picture?

Case Study of Recognition Patterns in Haunted People Syndrome

Haunted People Syndrome (HP-S) denotes individuals who recurrently report various “supernatural” encounters in everyday settings ostensibly due to heightened somatic-sensory sensitivities to dis-ease states (e.g., marked but sub-clinical levels of distress), which are contextualized by paranormal beliefs and reinforced by perceptual contagion effects. This view helps to explain why these anomalous experiences often appear to be idioms of stress or trauma. We tested the validity and practical utility of the HP-S concept in an empirical study of an active and reportedly intense ghostly episode that was a clinical referral. The case centered on the life story of the primary percipient, a retired female healthcare worker. Secondary percipients included her husband and adult daughter, all of whom reported an array of benign and threatening anomalies (psychological and physical in nature) across five successive residences. Guided by prior research, we administered the family online measures of transliminality, sensory-processing sensitivity, paranormal belief, locus of control, desirability for control, and a standardized checklist of haunt-type phenomena. The primary percipient also completed a measure of adverse childhood events and supplied an event diary of her anomalous experiences. We found reasonably consistent support for HP-S from a set of quantitative observations that compared five proposed syndrome features against the family members’ psychometric profiles and the structure and contents of their anomalous experiences. Specifically, the reported anomalies both correlated with the family’s scores on transliminality and paranormal belief, as well as elicited attributions and reaction patterns aligned with threat (agency) detection. There was also some evidence of perceptual congruency among the family members’ anomalous experiences. Putative psi cannot be ruled out, but we conclude that the family’s ordeal fundamentally involved the symptoms and manifestations of thin (or “permeable”) mental boundary functioning in the face of unfavorable circumstances or overstimulating environments and subsequently acerbated by poor emotion regulation, histrionic and catastrophizing reactions, and active confirmation biases.

Phenomenology and content of the inhaled N, N-dimethyltryptamine (N, N-DMT) experience

Understanding the phenomenology and content of the inhaled N, N, dimethyltryptamine (N, N-DMT) experience is critical to facilitate and support ongoing research and therapeutic models targeting mental health conditions and central nervous system pathology. A qualitative analysis was conducted of all N, N-DMT experiences posted to the r/DMT Reddit community over a 10-year period from 2009 to 2018. A total of 3778 experiences from 3305 posts were included in this study. A median dose of N, N-DMT of 40.0 mg [interquartile range (IQR), 27.5 to 50.0] and a median experience duration of 10 min (IQR, 5.0 to 15.0) were identified. The most common somatic effects were somaesthesias (n = 1415, 37.5%) and an auditory ringing (n = 583, 15.4%). Visualizations predominantly consisted of fractals, shapes, patterns (n = 1231, 32.6%) and vivid colours (n = 953, 25.2%). Entity encounters were reported in 45.5% (n = 1719) of the experiences and involved predominantly a feminine phenotype (n = 416, 24.2%); deities (n = 293, 17.0%); aliens (n = 281, 16.3%); creature-based entities (n = 158, 9.2%, including reptilian and insectoid beings); mythological beings (n = 144, 8.4%, including machine elves); and jesters (n = 112, 6.5%). Entity interactions were predominantly positive (n = 600, 34.9% of encounters) involving benevolent, comforting, protecting, or outwardly caring interactions. A companion-type, pedagogical, or guide-type interaction was identified 32.4% of encounters (n = 557). Common typology, architecture, and structural features of the "DMT world" included descriptions of alternate or higher dimensions (n = 952, 25.2%); rooms [n = 582, 15.4%, including the "waiting room" (n = 105, 2.8%)], and a tunnel (n = 390, 10.3%). Features of mystical and ego-dissolution experiences were common. Additional rewarding aspects were identified, including a sense of familiarity and the acceptance/removal of the fear of death. Challenging and difficult responses were less frequent but also documented. Statements of profundity were identified in 232 experiences (6.1%), including pronouncing the experience or an aspect of the experience as the most "beautiful" or feeling the most "beautiful" of their life (n = 47, 1.2%). This study identified common phenomenological themes and content of naturalistic inhaled N, N-DMT experiences. Major thematic domains included (1) physical and somatic experiences; (2) visualizations and imagery; (3) entity encounters including entity phenotype, descriptors, attributes, disposition, and characteristics of the interaction; (4) typology, architectural features, structural characteristics, and scenery of the "DMT world"; (5) alerations in consciousness (including mystical experiences, out-of-body experiences, and ego-dissolution); (6) emotional responses (including positive, rewarding, difficult, and challenging); and (7) statements of profundity.

Psychedelics and Psychotherapy: Cognitive-Behavioral Approaches as Default

The acute subjective effects of psychedelics are responsive to users' expectations and surroundings (i.e., "set and setting"). Accordingly, a great deal of thought has gone into designing the psychosocial context of psychedelic administration in clinical settings. But what theoretical paradigms inform these considerations about set and setting? Here, we describe several historical, sociological influences on current psychedelic administration in mainstream European and American clinical research settings, including: indigenous practices, new age spirituality from the 1960s, psychodynamic/psychoanalytic approaches, and cognitive-behavioral approaches. We consider each of these paradigms and determine that cognitive-behavioral therapies, including newer branches such as acceptance and commitment therapy (ACT), have the strongest rationale for psychedelic-assisted psychotherapy going forward. Our primary reasons for advocating for cognitive-behavioral approaches include, (1) they avoid issues of cultural insensitivity, (2) they make minimal speculative assumptions about the nature of the mind and reality, (3) they have the largest base of empirical support for their safety and effectiveness outside of psychedelic therapy. We then propose several concepts from cognitive-behavioral therapies such as CBT, DBT, and ACT that can usefully inform the preparation, session, and integration phases of psychedelic psychotherapy. Overall, while there are many sources from which psychedelic psychotherapy could draw, we argue that current gold-standard, evidence-based psychotherapeutic paradigms provide the best starting point in terms of safety and efficacy.

N,N-dimethyltryptamine and Amazonian ayahuasca plant medicine

OBJECTIVE

Reports have indicated possible uses of ayahuasca for the treatment of conditions including depression, addictions, post-traumatic stress disorder, anxiety and specific psychoneuroendocrine immune system pathologies. The article assesses potential ayahuasca and N,N-dimethyltryptamine (DMT) integration with contemporary healthcare. The review also seeks to provide a summary of selected literature regarding the mechanisms of action of DMT and ayahuasca; and assess to what extent the state of research can explain reports of unusual phenomenology.

DESIGN

A narrative review.

RESULTS

Compounds in ayahuasca have been found to bind to serotonergic receptors, glutaminergic receptors, sigma-1 receptors, trace amine-associated receptors, and modulate BDNF expression and the dopaminergic system. Subjective effects are associated with increased delta and theta oscillations in amygdala and hippocampal regions, decreased alpha wave activity in the default mode network, and stimulations of vision-related brain regions particularly in the visual association cortex. Both biological processes and field of consciousness models have been proposed to explain subjective effects of DMT and ayahuasca, however, the evidence supporting the proposed models is not sufficient to make confident conclusions. Ayahuasca plant medicine and DMT represent potentially novel treatment modalities.

CONCLUSIONS

Further research is required to clarify the mechanisms of action and develop treatments which can be made available to the general public. Integration between healthcare research institutions and reputable practitioners in the Amazon is recommended.

Psychedelic Experiences and Mindfulness are Associated with Improved Wellbeing

Both psychedelics and mindfulness are recently emerging topics of interest in academia and popular culture. The Prevalence of personal meditation practices and recreational psychedelic use has consistently increased in the past decade. While clinical work has shown both to improve long-term wellbeing, data on naturalistic applications of psychedelics and mindfulness are lacking. The current study examined the relationship between psychedelic use, mindfulness, and multi-faceted wellbeing as an outcome. Hierarchical regression was used to quantify these associations on a sample of people (N = 1,219) who engage in both meditation practices and psychedelic use. Results show that both mindfulness and mystical experiences are associated with substantial increases in wellbeing. Psychedelics were found to be a moderator of the relationship between mystical experience wellbeing. These data are among the first to establish a strong relationship between personal mindfulness practice, recreational psychedelic use, and overall psychological wellbeing in a naturalistic framework.

A Single Belief-Changing Psychedelic Experience Is Associated With Increased Attribution of Consciousness to Living and Non-living Entities

Introduction

Although the topic of consciousness is both mysterious and controversial, psychedelic drugs are popularly believed to provide unique insights into the nature of consciousness despite a lack of empirical evidence.

Methods

This study addresses the question of whether psychedelics change the attribution of consciousness to a range of living and non-living entities. A survey was conducted in 1,606 respondents who endorsed a belief changing psychedelic experience.

Results

Participants rated their attributions of consciousness to a range of living and non-living entities before and after their psychedelic experience. Superstitious beliefs and belief in freewill were also assessed. From before the experience to after, there were large increases in attribution of consciousness to various entities including non-human primates (63-83%), quadrupeds (59-79%), insects (33-57%), fungi (21-56%), plants (26-61%), inanimate natural objects (8-26%), and inanimate manmade objects (3-15%). Higher ratings of mystical experience were associated with greater increases in the attribution of consciousness. Moreover, the increased attributions of consciousness did not decrease in those who completed the survey years after the psychedelic experience. In contrast to attributions of consciousness, beliefs in freewill and superstitions did not change. Notably, all findings were similar when restricted to individuals reporting on their first psychedelic experience.

Discussion

This study demonstrates that, among people who reported belief-changing psychedelic experiences, attribution of consciousness to various entities increases. Future prospective psychedelic drug administration studies that control for expectancies are needed.

Presence, Trust, and Empathy: Preferred Characteristics of Psychedelic Carers

Research into psychedelic-assisted psychotherapy (PAP) is rapidly increasing with best practice guidelines being continuously updated. Yet the key principals of such guidelines are based on evidence accumulated during earlier research into these treatments and trans-disciplinary psychotherapeutic knowledge. One area of practice-based evidence that has not been considered is that accumulated by people who use psychedelics (PWUP) outside of clinical contexts. We conducted a thematic analysis of 403 posts on two online discussion forums with the aim of gathering information regarding the preferences of PWUP for characteristics they value in their carers in nonclinical contexts. We found three key distinct characteristics that PWUP preferred among their carers: presence, trust, and empathy. The characteristics were often consistent with the existing literature on PAP, though at times extended current understandings of key characteristics of PAP therapists, with the notion of carers being able to “hold space” during the psychedelic experience seen as an integral component of effective therapeutic outcomes that deserves more attention. Data obtained from PWUP in nonclinical contexts can be used to triangulate existing principles contained within PAP treatment guidelines and identify areas for further investigation.

Validation of the Psychological Insight Scale: A new scale to assess psychological insight following a psychedelic experience

INTRODUCTION

As their name suggests, 'psychedelic' (mind-revealing) compounds are thought to catalyse processes of psychological insight; however, few satisfactory scales exist to sample this. This study sought to develop a new scale to measure psychological insight after a psychedelic experience: the Psychological Insight Scale (PIS).

METHODS

The PIS is a six- to seven-item questionnaire that enquires about psychological insight after a psychedelic experience (PIS-6) and accompanied behavioural changes (PIS item 7). In total, 886 participants took part in a study in which the PIS and other questionnaires were completed in a prospective fashion in relation to a planned psychedelic experience. For validation purposes, data from 279 participants were analysed from a non-specific 'global psychedelic survey' study.

RESULTS

Principal components analysis of PIS scores revealed a principal component explaining 73.57% of the variance, which displayed high internal consistency at multiple timepoints throughout the study (average Cronbach's α = 0.94). Criterion validity was confirmed using the global psychedelic survey study, and convergent validity was confirmed via the Therapeutic-Realizations Scale. Furthermore, PIS scores significantly mediated the relationship between emotional breakthrough and long-term well-being.

CONCLUSION

The PIS is complementary to current subjective measures used in psychedelic studies, most of which are completed in relation to the acute experience. Insight - as measured by the PIS - was found to be a key mediator of long-term psychological outcomes following a psychedelic experience. Future research may investigate how insight varies throughout a psychedelic process, its underlying neurobiology and how it impacts behaviour and mental health.

The incubus phenomenon: Prevalence, frequency and risk factors in psychiatric inpatients and university undergraduates

BACKGROUND

The incubus phenomenon is a paroxysmal sleep-related disorder characterized by the visuotactile sensation of a person or entity exerting pressure on one's thorax during episodes of sleep paralysis and (apparent) wakefulness. This terrifying phenomenon is relatively unknown even though a previous meta-analysis indicated a lifetime prevalence of 0.11 for individuals in the general population and of 0.41 for selected at-risk groups, including people diagnosed with schizophrenia and students. Since the studies reviewed did not always make a strict distinction between the incubus phenomenon and isolated sleep paralysis, we carried out a cross-sectional study in a contemporary patient and student sample to attain current, more detailed data on the incubus phenomenon.

MATERIALS AND METHODS

In a cross-sectional design, we used the Waterloo Unusual Sleep Experience Questionnaire (WUSEQ) to screen patients with severe psychiatric disorders and university undergraduates to establish and compare prevalence rates, frequencies of occurrence, and risk factors for the incubus phenomenon.

RESULTS

Having interviewed 749 people, comprising 606 students and 143 patients with a schizophrenia spectrum or related disorder who had been acutely admitted to a secluded nursing ward, we computed a reported lifetime prevalence of 0.12 and 0.09, respectively, which rates were not statistically different. In both groups, the phenomenon was more common in people with a non-Western European background. Risk factors noted for the students were the use of psychotropic medication and the lifetime presence of an anxiety disorder, eating disorder, or sleeping disorder. We found no associations with age or gender in either group.

CONCLUSION

The 0.09 and 0.12 lifetime prevalence rates we recorded for the incubus phenomenon in students and psychiatric inpatients is substantially lower than the 0.41 found in an earlier meta-analysis. We tentatively attribute this difference to an overgeneralization in previous studies but also discuss alternative explanations. The elevated prevalence among non-Western European participants may well be due to the fact that the topic continues to be part of the cultural and religious heritage of many non-Western countries.

The Watts Connectedness Scale: a new scale for measuring a sense of connectedness to self, others, and world

RATIONALE

A general feeling of disconnection has been associated with mental and emotional suffering. Improvements to a sense of connectedness to self, others and the wider world have been reported by participants in clinical trials of psychedelic therapy. Such accounts have led us to a definition of the psychological construct of 'connectedness' as 'a state of feeling connected to self, others and the wider world'. Existing tools for measuring connectedness have focused on particular aspects of connectedness, such as 'social connectedness' or 'nature connectedness', which we hypothesise to be different expressions of a common factor of connectedness. Here, we sought to develop a new scale to measure connectedness as a construct with these multiple domains. We hypothesised that (1) our scale would measure three separable subscale factors pertaining to a felt connection to 'self', 'others' and 'world' and (2) improvements in total and subscale WCS scores would correlate with improved mental health outcomes post psychedelic use.

OBJECTIVES

To validate and test the 'Watts Connectedness Scale' (WCS).

METHODS

Psychometric validation of the WCS was carried out using data from three independent studies. Firstly, we pooled data from two prospective observational online survey studies. The WCS was completed before and after a planned psychedelic experience. The total sample of completers from the online surveys was N = 1226. Exploratory and confirmatory factor analysis were performed, and construct and criterion validity were tested. A third dataset was derived from a double-blind randomised controlled trial (RCT) comparing psilocybin-assisted therapy (n = 27) with 6 weeks of daily escitalopram (n = 25) for major depressive disorder (MDD), where the WCS was completed at baseline and at a 6-week primary endpoint.

RESULTS

As hypothesised, factor analysis of all WCS items revealed three main factors with good internal consistency. WCS showed good construct validity. Significant post-psychedelic increases were observed for total connectedness scores (η2 = 0.339, p < 0.0001), as well as on each of its subscales (p < 0.0001). Acute measures of 'mystical experience', 'emotional breakthrough', and 'communitas' correlated positively with post-psychedelic changes in connectedness (r = 0.42, r = 0.38, r = 0.42, respectively, p < 0.0001). In the RCT, psilocybin therapy was associated with greater increases in WCS scores compared with the escitalopram arm (η_p2 = 0.133, p = 0.009).

CONCLUSIONS

The WCS is a new 3-dimensional index of felt connectedness that may sensitively measure therapeutically relevant psychological changes post-psychedelic use. We believe that the operational definition of connectedness captured by the WCS may have broad relevance in mental health research.

Administration of N,N-dimethyltryptamine (DMT) in psychedelic therapeutics and research and the study of endogenous DMT

As with all drugs, the route, form, and/or dose of a substance administered or applied can play a defining role in its overall pharmacology and use as a therapeutic. This review will focus on these factors as they relate to the psychedelic N,N-dimethyltryptamine (DMT). It will examine the positive and negative aspects of different formulations and routes of administration of DMT and the observed effects from such administrations in the form of ayahuasca teas; oral "pharmahuasca"; injections by intravenous (IV) and intramuscular (IM) routes; inhalation, insufflation; and other routes; and high-dose, low-dose, and "micro-dose" effects. The review will consider possible oral route of administration alternatives that would not require concomitant use of a monoamine oxidase inhibitor. The review will then address the current research findings for DMT from in vivo and in vitro studies as well as the possibility that these findings may be revealing the role of endogenous DMT in normal brain function.

An Encounter With the Other: A Thematic and Content Analysis of DMT Experiences From a Naturalistic Field Study

Introduction: N,N-dimethyltryptamine (DMT) is an endogenous serotonergic psychedelic capable of producing radical shifts in conscious experience. Increasing trends in its use, as well as new trials administering DMT to patients, indicate the growing importance of a thorough elucidation of the qualitative content, over and above structure, which the drug occasions. This is particularly in light of the hyper-real, otherworldly, and often ontologically challenging yet potentially transformative, nature of the experience, not least encounters with apparently non-self social agents. Laboratory studies have been limited by clinical setting and lacking qualitative analyses of experiential content, while online surveys' limitations lie in retrospective design, uncontrolled use, and both of which not guaranteeing 'breakthrough' experiences, i.e., producing very strong psychoactive effects. Methods: We report on the first naturalistic field study of DMT use including its qualitative analysis. Screened, healthy, anonymised and experienced DMT users were observed during their non-clinical use of the drug at home (40-75 mg inhaled). In-depth semi-structured interviews (inspired by the micro-phenomenological technique) were employed immediately after their experience. This paper reports on the thematic analysis of one major domain of the breakthrough experiences elicited, the 'other'. Thirty-six post-DMT experience interviews with mostly Caucasian (83%) males (eight female) of average 37 years were predominantly inductively coded. Results: Invariably, profound and highly intense experiences occurred. The first overarching category comprised the encounter with other 'beings' (94% of reports), encompassing super-ordinate themes including the entities' role, appearance, demeanour, communication and interaction; while the second overarching category comprised experiences of emerging into other 'worlds' (100% of reports), encompassing super-ordinate themes of the scene, the contents and quality of the immersive spaces. Many further mid-level themes and subthemes also illuminate the rich content of the DMT experience. Discussion: The present study provides a systematic and in-depth analysis of the nuanced content of the otherworldly encounter within the breakthrough DMT experience, as well as elaborating on the resonances both with previous DMT studies focusing on entity encounters and other types of extraordinary experiences entailing such encounters. These include the alien abduction, folkloric, shamanic and near-death experience. Putative neural mechanisms of these features of the DMT experience and its promise as a psychotherapeutic agent are discussed in light of such findings.

Psychedelic Epistemology: William James and the “Noetic Quality” of Mystical Experience

William James proposed in 1902 that states of mystical experience, central to his idea of religious experience, can be identified based on their ineffability and their noetic quality. The epistemological category of the noetic quality, modified by W. T. Stace in 1960, plays a central but somewhat confounding role in today’s biomedical research involving psychedelic drugs such as psilocybin and LSD. Using scales based on James, it can be shown that psychedelics “reliably occasion” intense subjective states of experience or mystical states. It is debated whether these states are necessary for the wide range of possible mental health therapeutic benefits that appear to follow. This paper reviews what James said about the noetic quality and its relationship to religious experience, epistemology, and states of mystical experience. It explores how the noetic quality is measured in today’s research, addressing a growing list of concerns that psychedelic science can be epistemologically biased, that it is hostile to atheistic or physicalist views, that it injects religion unduly into science, or that it needs to find ways to eliminate the mystical element, if not the entire intense subjective experience altogether.

Psychedelics alter metaphysical beliefs

Can the use of psychedelic drugs induce lasting changes in metaphysical beliefs? While it is popularly believed that they can, this question has never been formally tested. Here we exploited a large sample derived from prospective online surveying to determine whether and how beliefs concerning the nature of reality, consciousness, and free-will, change after psychedelic use. Results revealed significant shifts away from 'physicalist' or 'materialist' views, and towards panpsychism and fatalism, post use. With the exception of fatalism, these changes endured for at least 6 months, and were positively correlated with the extent of past psychedelic-use and improved mental-health outcomes. Path modelling suggested that the belief-shifts were moderated by impressionability at baseline and mediated by perceived emotional synchrony with others during the psychedelic experience. The observed belief-shifts post-psychedelic-use were consolidated by data from an independent controlled clinical trial. Together, these findings imply that psychedelic-use may causally influence metaphysical beliefs-shifting them away from 'hard materialism'. We discuss whether these apparent effects are contextually independent.

Tactile and Somatic Hallucinations in a Muslim Population of Psychotic Patients

Background: Tactile and somatic hallucinations are distressing phenomena that have hardly been researched. The few studies that have been published focus on their occurrence in neurodegenerative disorders and substance use, and, surprisingly, not on schizophrenia spectrum disorders. Objective: To fill this gap in our knowledge, we sought to explore the phenomenological characteristics of tactile and somatic hallucinations in a group of psychotic Muslim patients. Since many Muslims attribute such experiences to jinn (invisible spirits) and jinn are often perceived in multiple sensory modalities, we not only charted the involvement of the tactile and somatic modalities but also their interrelatedness with hallucinations in other sensory modalities. Methods: We performed a cross-sectional study using a semi-structured interview and dedicated questionnaire. Results: Of the 42 Muslim inpatients mostly diagnosed with a schizophrenia spectrum disorder, 62% reported to suffer from tactile and/or somatic hallucinations. Their phenomenological characteristics varied, with 96% being multimodal in nature and 38% taking the form of full-blown entity/jinn encounters. In comparison to other entity experiences, the involvement of the tactile and somatic modalities was exceptionally high, as was the level of ensuing distress. Regarding the order of recruitment of the various sensory modalities, we suggest the involvement of an underlying stochastic process. Conclusion: Muslim patients with severe psychosis can have tactile and somatic hallucinations, of which a large number are multimodal or full-blown entity/jinn encounters, which are almost invariably appreciated as harrowing. On the basis of our findings we make recommendations for further research and clinical practice.

Psychedelics, Sociality, and Human Evolution

Our hominin ancestors inevitably encountered and likely ingested psychedelic mushrooms throughout their evolutionary history. This assertion is supported by current understanding of: early hominins' paleodiet and paleoecology; primate phylogeny of mycophagical and self-medicative behaviors; and the biogeography of psilocybin-containing fungi. These lines of evidence indicate mushrooms (including bioactive species) have been a relevant resource since the Pliocene, when hominins intensified exploitation of forest floor foods. Psilocybin and similar psychedelics that primarily target the serotonin 2A receptor subtype stimulate an active coping strategy response that may provide an enhanced capacity for adaptive changes through a flexible and associative mode of cognition. Such psychedelics also alter emotional processing, self-regulation, and social behavior, often having enduring effects on individual and group well-being and sociality. A homeostatic and drug instrumentalization perspective suggests that incidental inclusion of psychedelics in the diet of hominins, and their eventual addition to rituals and institutions of early humans could have conferred selective advantages. Hominin evolution occurred in an ever-changing, and at times quickly changing, environmental landscape and entailed advancement into a socio-cognitive niche, i.e., the development of a socially interdependent lifeway based on reasoning, cooperative communication, and social learning. In this context, psychedelics' effects in enhancing sociality, imagination, eloquence, and suggestibility may have increased adaptability and fitness. We present interdisciplinary evidence for a model of psychedelic instrumentalization focused on four interrelated instrumentalization goals: management of psychological distress and treatment of health problems; enhanced social interaction and interpersonal relations; facilitation of collective ritual and religious activities; and enhanced group decision-making. The socio-cognitive niche was simultaneously a selection pressure and an adaptive response, and was partially constructed by hominins through their activities and their choices. Therefore, the evolutionary scenario put forward suggests that integration of psilocybin into ancient diet, communal practice, and proto-religious activity may have enhanced hominin response to the socio-cognitive niche, while also aiding in its creation. In particular, the interpersonal and prosocial effects of psilocybin may have mediated the expansion of social bonding mechanisms such as laughter, music, storytelling, and religion, imposing a systematic bias on the selective environment that favored selection for prosociality in our lineage.

New Insights Into the Clinical and Nonclinical Effects of Psychedelic Substances

Abstract. After decades of stagnation, research on psychedelic substances (such as lysergic acid diethylamide [LSD], psilocybin, or N,N-dimethyltryptamine [DMT]) has experienced a renaissance over the last 10 years, with various major research programs being conducted across Europe and the United States. This research primarily investigates the potential of psychedelics in the treatment of mental health disorders, their short- and long-term effects on recreational users, and the neurological and cognitive processes responsible for their effects. The present review provides a concise summary of the most recent insights gained from this research. We briefly outline the history of psychedelic research, the objective and subjective effects caused by these substances, the prevalence and socio-psychological correlates of their use, as well as their potential for harm. Subsequently, we review empirical research on the beneficial effects of psychedelics in clinical samples, focusing on their efficacy in the treatment of major depression, anxiety, and substance use disorders, and discuss research on the proposed neural and cognitive mechanisms behind these effects. We then review research on their effects on healthy subjects, focusing on psychological well-being as well as changes in personality, nature-relatedness, and creativity. Finally, we review empirical evidence regarding the long-term effects of single experiences with psychedelics and conclude with a summary and outlook.

On Revelations and Revolutions: Drinking Ayahuasca Among Palestinians Under Israeli Occupation

The ritualistic use of ayahuasca can induce a feeling of unity and harmony among group members. However, such depoliticized feelings can come in the service of a destructive political status quo in which Palestinians are marginalized. Through 31 in-depth interviews of Israelis and Palestinians who drink ayahuasca together, and through participatory observations, such rituals were examined. In this setting marginalization was structurally rooted by the group's inability to recognize Palestinian national identity or admit the ongoing Israeli injustice toward Palestinians. Although the groups avoided politics, they still find their way into these rituals. This happened through occasional ayahuasca-induced revelatory events, in which individuals were confronted with a pressing truth related to the oppressive relations between Jewish Israelis and Palestinians. Three case studies of such revelatory events are described in this paper. Affected by emotions of pain, anger, and guilt, these participants developed resistance toward the hegemonic Israeli ritual structure. This was followed by an urge to deliver an emancipatory message to the rest of the group, usually through a song. Moreover, affected subjects developed a long-lasting fidelity to the truth attained at these events. In time, this fidelity led to the expansion of ayahuasca practices to other Palestinians and the politicization of the practice. The article draws on Badiou's theory in Being and Event (1988) to analyze the relations between the Israeli ritual structure, the Palestinian revelatory event, and the emancipatory fidelity that followed. Badiou's theory elucidates the egalitarian revolutionary potential, which is part of the sociopsychopharmacology of psychedelics.

Psychedelic Drugs and Atheism: Debunking the Myths

Two recent surveys of people who took psychedelic drugs and reported “God experience encounters”, along with successful clinical trials using psychedelic therapy for depression, have given rise to public misconceptions about psychedelics and atheism. Specifically, three inferences have been drawn: (1) that the psychedelic experience tends to dissolve atheist convictions; (2) that atheist convictions, once dissolved, are replaced with traditional monotheist beliefs; and (3) that atheism and depression somehow correlate as afflictions for which psychedelic drugs offer relief. This paper argues, based on analysis of the studies and trials along with relevant supplemental evidence, that each of these popular inferences is substantially misleading. Survey data do not indicate that most psychedelic atheists have cleanly cut ties with their former convictions, and there is strong evidence that they have not traded atheism for traditional monotheism. Both personal testimony and the effectiveness of microdose clinical trials serve to complicate any notion that a psychedelic drug alleviates symptoms of depression by “curing” atheism. The paper then extends its focus to argue that the broader field of neurotheology includes elements that contribute to these popular misconceptions.

Four individuals' experiences during and following a psilocybin truffle retreat in the Netherlands

This article reports on the experiences of four healthy individuals who attended a legal psilocybin truffle retreat in the Netherlands. The study employed a qualitative phenomenological approach, using semi-structured interviews to gain an understanding of participants' psilocybin experiences and their after-effects. The experiential themes that emerged from these case studies closely match themes that have been identified in previous studies of psilocybin, including variability of the experience, the presence of mystical-type features, significant changes to subjective sense of self, and a generalized sense of connectedness. Participants framed their narrative accounts around moments of key insight, and these insights were related to a sense of connection: to self, others, and to a broader relational ontology. Embodiment, currently an understudied topic in psychedelic research, also emerged as a theme. The case studies presented here provide preliminary evidence to suggest that for healthy individuals in a well-controlled and supportive retreat setting, a high dose of psilocybin can lead to enduring positive after-effects that last up to twelve months.

The Subjective Effects of Psychedelics May Not Be Necessary for Their Enduring Therapeutic Effects

Psychedelics represent one of the most promising classes of experimental medicines for the treatment of neuropsychiatric disorders due to their ability to promote neural plasticity and produce both rapid and sustained therapeutic effects following a single administration. Conventional wisdom holds that peak mystical experiences induced by psychedelics are a critical component of their therapeutic mechanisms of action, though evidence supporting that claim is largely correlational. Here, I present data suggesting that the subjective effects induced by psychedelics may not be necessary to produce long-lasting changes in mood and behavior. Understanding the role of subjective effects in the therapeutic mechanisms of psychedelics will have important implications for both basic neuroscience and for increasing patient access to the next generation of medicines developed as a result of psychedelic research.

Leroy's elusive little people: A systematic review on lilliputian hallucinations

Lilliputian hallucinations concern hallucinated human, animal or fantasy entities of minute size. Having been famously described by the French psychiatrist Raoul Leroy in 1909, who wrote from personal experience, to date they are mentioned almost routinely in textbooks of psychiatry, albeit with little in-depth knowledge. I therefore systematically reviewed 145 case reports and case series comprising 226 case descriptions, concluding that lilliputian hallucinations are visual (61 %) or multimodal (39 %) in nature. In 97 % of the cases, they are perceived as grounded in the actual environment, thus indicating involvement of higher-level regions of the perceptual network subserving the fusion of sensory and hallucinatory content. Perceptual release and deafferentiation are the most likely underlying mechanisms. Etiology is extremely diverse, with schizophrenia spectrum disorder, alcohol use disorder and loss of vision accounting for 50 % of the cases and neurological disease for 36 %. Recovery was obtained in 62 % of the cases, whereas 18 % of the cases ended in chronicity and 8 % in death. Recommendations are made for clinical practice and future research.

The acute effects of classic psychedelics on memory in humans

RATIONALE

Memory plays a central role in the psychedelic experience. The spontaneous recall and immersive reliving of autobiographical memories has frequently been noted by researchers and clinicians as a salient phenomenon in the profile of subjective effects of classic psychedelic drugs such as psilocybin, LSD, and ayahuasca. The ability for psychedelics to provoke vivid memories has been considered important to their clinical efficacy.

OBJECTIVE

This review aims to examine and aggregate the findings from experimental, observational, and qualitative studies on the acute modulation of memory by classic psychedelics in humans.

METHOD

A literature search was conducted using PubMed and PsycInfo as well as manual review of references from eligible studies. Publications reporting quantitative and/or qualitative findings were included; animal studies and case reports were excluded.

RESULTS

Classic psychedelics produce dose-dependently increasing impairments in memory task performance, such that low doses produce no impairment and higher doses produce increasing levels of impairment. This pattern has been observed in tasks assessing spatial and verbal working memory, semantic memory, and non-autobiographical episodic memory. Such impairments may be less pronounced among experienced psychedelic users. Classic psychedelics also increase the vividness of autobiographical memories and frequently stimulate the recall and/or re-experiencing of autobiographical memories, often memories that are affectively intense (positively or negatively valenced) and that had been avoided and/or forgotten prior to the experience.

CONCLUSIONS

Classic psychedelics dose-dependently impair memory task performance but may enhance autobiographical memory. These findings are relevant to the understanding of psychological mechanisms of action of psychedelic-assisted psychotherapy.

Entity encounters and the therapeutic effect of the psychedelic mystical experience

Research suggests that the clinical and therapeutic effects of psychedelics are related to their ability to induce a mystical-type experience. One particularly interesting feature of the psychedelic mystical experience is the entity encounter - people who take psychedelics sometimes describe meetings with seemingly autonomous entities which appear to possess intelligence and agency. While there has been little empirical research into psychedelic entity phenomena, qualitative studies and anecdotal reports suggest that entity encounters can have profound and lasting positive after-effects. Based on the existing data, this article argues that there is value in exploring the therapeutic potential of psychedelic entity encounters. Specifically, it proposes three possible ways that entity encounters might mediate the therapeutic effect of the psychedelic mystical experience.

A Spectrum of Selves Reinforced in Multilevel Coherence: A Contextual Behavioural Response to the Challenges of Psychedelic-Assisted Therapy Development

Psychedelic-assisted therapy research for depression and PTSD has been fast tracked in the United States with the Food and Drugs Administration (FDA) granting breakthrough designations for MDMA (post-traumatic stress disorder) and psilocybin (major depressive disorder). The psychotherapeutic treatments accompanying these psychedelics have not been well-studied and remain controversial. This article reviews the challenges unique to psychedelic-assisted therapy and introduces a newly optimised psychological flexibility model that adapts Contextual Behavioural Science (CBS)/Acceptance and Commitment Therapy (ACT) to those multiple challenges, including ego inflation, traumatic memories, and the perceived presence of entities. A methodology aligned with biological mechanisms, psychological processes and therapeutic contexts may be advantageous for improving outcomes. This model expands ACT by integrating practices and data from psychedelic-assisted therapy research into a Contextual Behavioural Science framework, allowing both fields to inform each other. Psychological flexibility processes are questioned and adapted to a psychedelic context, and interventions that operationalise these processes are considered. The principle through-line of the paper is to consider varied constructs of Self, as understood by these fields, and integrates respective elements of varied self-models, interventions and data into a Spectrum of Selves model for psychedelic-assisted therapy. Secondly the paper examines how to select and retain new self-perspectives and their corresponding behaviours systemically, drawing from evolutionary science principles. A case example of such behavioural reinforcement is provided, as well as a psychedelic integration checklist to guide the practical implementation of such an approach. This method can enable a coherent therapeutic framework with clear operational relationships between (1) problematic behaviour patterns that an individual wishes to address (2) the guided psychedelic experiences of that individual, and (3) the barriers to maintaining any changes, thus increasing theoretical-practical coherence, broadening treatment benefits and reducing relapse in psychedelic-assisted therapy. Research questions for further developing a CBS-consistent psychedelic-assisted therapy are offered.