Psychopharmacology
November 26, 2018
Steliana Yanakieva, Naya Polychroni, Neiloufar Family et al.
169 citations
Microdoses of LSD (5, 10, and 20 μg) caused older adults to over-reproduce time intervals of 2000 milliseconds and longer, with the strongest effect at 10 μg. This temporal dilation occurred without noticeable changes in perception, mentation, or concentration, and was independent of any subjective drug effects. The findings suggest that LSD can directly alter interval timing at doses too low to produce conscious psychedelic effects, indicating a dissociation between neurochemical influences on time perception and altered states of consciousness.
PLoS ONE
October 24, 2023
Jules Evans, Oliver Robinson, Eirini K. Argyri et al.
166 citations
Long-term adverse experiences after psychedelic use can last weeks, months, or even years and are understudied. A mixed-method study of 608 participants who reported extended difficulties found the most common challenges were anxiety and fear, existential struggle, social disconnection, depersonalization, and derealization. For about one-third of participants, problems persisted over a year; for one-sixth, they lasted more than three years. Shorter difficulties were predicted by knowing the dose and drug type and by lower difficulty during the experience; a narrower range of difficulties was predicted by taking the drug in a guided setting. Implications for harm reduction are discussed.
Frontiers in Psychology
August 19, 2021
Jessica Sophie Corneille, David Luke
61 citations
Spontaneous Spiritual Awakenings (SSAs) are sudden experiences of oneness with ultimate reality, God, or the universe that have been little studied despite anecdotal reports of lasting positive change. A survey of 152 people who had their most powerful awakening found that Spontaneous Kundalini Awakenings (SKAs) were significantly more physical but not significantly more negative than SSAs; both were overwhelmingly positive overall. The experiences resembled drug-induced altered states, especially those from classic psychedelics like DMT and psilocybin, though greater in magnitude. Personality traits of absorption and temporal lobe lability predicted the likelihood of having such awakenings.
Frontiers in Psychology
December 16, 2021
Pascal Michael, David Luke, Oliver Robinson
39 citations
In a naturalistic field study, experienced users of the psychedelic N,N-dimethyltryptamine (DMT) were observed taking the drug at home (40–75 mg inhaled) and then interviewed immediately afterward. Thematic analysis of 36 interviews revealed that nearly all participants (94%) reported encountering other 'beings' with distinct roles, appearances, and forms of communication, while every participant described emerging into other 'worlds' with immersive scenes and contents. These findings systematically detail the hyper-real, otherworldly content of the breakthrough DMT experience and connect it to phenomena such as alien abduction accounts, shamanic journeys, and near-death experiences.
Drugs and Alcohol Today
June 1, 2008
David Luke
36 citations
No Summary
International Journal of Transpersonal Studies
January 1, 2012
David Luke
35 citations
This review examines the relationship between psychoactive substances and paranormal phenomena studied in parapsychology, focusing on extrasensory perception (telepathy, precognition, clairvoyance), out-of-body experiences, and near-death experiences. It draws from parapsychology, transpersonal studies, anthropology, ethnobotany, psychiatry, and neurobiology. The paper is organized into neurochemical models of paranormal experience, field reports of intentional and spontaneous phenomena, surveys of belief and experience, experimental research, and a methodological critique with recommendations. Psychokinesis, aura vision, encounter experiences, and sleep paralysis are minimally covered due to limited connections with psychoactive drugs in the literature.
PloS one
January 1, 2025
Eirini K Argyri, Jules Evans, David Luke et al.
27 citations
Psychedelic experiences can sometimes trigger long-lasting existential distress, marked by confusion about existence and purpose, alongside cognitive, emotional, social, and bodily difficulties. Interviews with 26 people who experienced such distress revealed that ontological challenges—struggles with understanding reality—were common. Participants alleviated distress primarily through 'grounding' practices: embodiment, social connection, and cognitive normalization of their experience. The findings suggest psychedelic experiences act as pivotal mental states that can facilitate transformative learning, challenging and expanding meaning-making. This work contributes to understanding how people reestablish coherence and grow after ontologically challenging psychedelic experiences.
Journal of Psychedelic Studies
August 8, 2022
Alexander Irvine, David Luke
27 citations
People with Hallucinogen Persisting Perceptual Disorder (HPPD) differ in personality and visual processing style depending on whether they experience the symptoms as distressing (HPPD II) or neutral/positive (HPPD I). In an online survey of 117 participants from HPPD and psychedelic user groups, those with HPPD I showed higher absorption and visual apophenia scores, and their group membership was predicted by higher drug use. Those with HPPD II had significantly higher trait anxiety, and their categorization was predicted by more negative precipitating experiences, lack of prior knowledge, and pre-existing anxiety diagnoses. Anxiety and negative experiences are linked to distressing persistent visual symptoms after hallucinogen use, while higher absorption and apophenia are linked to neutral or positive experiences.
Frontiers in Psychology
May 28, 2024
Oliver Robinson, Jules Evans, David Luke et al.
24 citations
After a psychedelic experience, some people face difficulties that last at least a day. An international survey of 608 such individuals found they used a variety of coping strategies. The most common individual strategies were meditation and prayer, followed by self-educational activities like reading and journaling. Social coping most often involved seeking support from friends or family, then from a therapist or coach. Helpful features of social support included feeling heard and accepted, a non-judgmental attitude, and sharing similar experiences. These findings can inform therapeutic interventions and educational resources for those experiencing extended post-psychedelic difficulties.
Journal of Psychopharmacology
March 1, 2022
Neiloufar Family, Peter S. Hendricks, Luke T. J. Williams et al.
23 citations
LSD doses of 50, 75, and 100 micrograms are tolerable and safe in healthy adults when administered in a novel group-based intervention paradigm with one attendant per participant. Thirty-two adults (mean age 28.8 years) received LSD or placebo across open-label and double-blind designs. No serious adverse events occurred; 28% of participants reported at least one mild expected adverse event and one moderate event. Peak blood plasma levels appeared 1.2 to 2 hours after administration, with an apparent half-life of 2.8 to 4.3 hours. LSD produced greater subjective effects than placebo, including mystical-type experiences. Further research is needed in clinical populations.
Psychoactives
May 25, 2023
Alexander Irvine, David Luke, Freya Harrild et al.
22 citations
People who had used psychedelics reported that the experiences strengthened or created a passionate, protective connection with nature. Those already close to nature felt psychedelics re-established and deepened that bond; those without a prior connection said psychedelics helped them form one. Central to these shifts were transpersonal experiences, especially a sense of interconnectedness, which was most often linked to changes in attitudes and behaviors. Participants also noted benefits of having the experience in a natural setting. The findings suggest psychedelics can foster a caring relationship with nature even in people not previously nature-oriented.
Journal of Psychedelic Studies
December 3, 2024
O. Robinson, J. Evans, R. Mcalpine et al.
21 citations
An online survey of 159 people who experienced difficulties lasting more than one day after using psychedelic drugs in the past 2–10 years found that social disconnection (72%), anxiety and panic attacks (68%), and existential struggle (65%) were the most common problems. Anxiety and panic attacks were rated as most severe, while existential struggle and diminished self-esteem lasted the longest, with average durations exceeding 15 months. Self-education was the most frequently used coping strategy for social disconnection and existential struggle, professional therapy worked best for depression and diminished self-esteem, and peer or family support helped most with anxiety and panic attacks. The findings point to the need for diverse support systems combining professional, educational, and community resources.
Journal of Psychedelic Studies
December 1, 2018
David Luke
20 citations
A letter reports a case of a person with apparent congenital aphantasia who experienced no visual imagery despite heavily smoking N,N-dimethyltryptamine, a psychedelic. This contrasts with a prior case in which an individual with aphantasia reported improved visual imagery after ayahuasca. The letter supports the idea that the prior case's aphantasia was acquired rather than congenital, and proposes further exploring this distinction in relation to psychedelics. It recommends that future psychedelic research include self-report measures like the Vividness of Visual Imagery Questionnaire and behavioral tasks such as binocular rivalry to index aphantasia.
Frontiers in psychology
January 1, 2023
Pascal Michael, David Luke, Oliver Robinson
19 citations
A person who had a near-death experience (NDE) while in a coma from bacterial meningoencephalitis later took 5MeO-DMT, an endogenous psychedelic. A thematic analysis of the NDE account and an interview about the drug experience found high comparability, including ego dissolution and transcendence of time and space. However, the NDE uniquely included a life review, encounters with the deceased, and a threshold experience. Despite similarities, the participant felt the two experiences were not similar enough to attribute the NDE to endogenous psychedelics. The authors speculate that the brain inflammation may have triggered neural activity similar to that of psychedelics, but note this hypothesis is speculative.
Journal of Psychopharmacology
January 1, 2023
Matthias Forstmann, Christina Sagioglou, Alexander Irvine et al.
18 citations
Among people who have used psychedelics, only past use of psilocybin—not LSD, mescaline, Salvia divinorum, ketamine, ibogaine, or DMT—reliably predicted a stronger sense of connection to nature (nature relatedness). The finding held even when people who had never used psychedelics were included in the analysis. For those who had used only psilocybin, more frequent use was linked to higher nature relatedness. This suggests that psilocybin may have a unique association with nature relatedness, possibly due to its pharmacology or the contexts in which it is used.
Journal of Humanistic Psychology
March 1, 2022
David Luke
18 citations
This essay reviews ten types of anomalous experiences—synaesthesia, extra-dimensional percepts, out-of-body experiences, near-death experiences, entity encounters, alien abduction, sleep paralysis, interspecies communication, possession, and psi (telepathy, precognition, clairvoyance, and psychokinesis)—that occur both spontaneously and with psychedelic substances. Taking a multidisciplinary approach, it explores what these phenomena reveal about the nature of 'expanded consciousness' and their implications for humanistic and transpersonal psychology, parapsychology, and the underlying neuroscience of such experiences.
Frontiers in psychology
January 1, 2023
Pascal Michael, David Luke, Oliver Robinson
16 citations
A naturalistic field study analyzed the content of breakthrough experiences after inhaling 40-75 mg of DMT in non-clinical home settings. Based on 36 interviews with experienced users (83% Caucasian, eight women, mean age 37), five overarching categories emerged: onset effects (sensory, emotion, body, space-time shifts), bodily effects (pleasurable, neutral, uncomfortable), sensorial effects (open-eye, visual, cross-modal), psychological effects (memory, language, awareness, sense of self, time distortions), and emotional effects (positive, neutral, challenging). The findings systematically detail the rich, self-referential content of the DMT state and its resonances with alien abduction, shamanic, and near-death experiences.
Seeing and Perceiving
January 1, 2012
David Luke, Devin Terhune, Ross Friday
11 citations
Synaesthesia, a condition where stimulation of one sense triggers perception in another, is frequently induced by psychedelic substances that act on the serotonin system, such as LSD and psilocybin. A survey of recreational drug users found that these serotonergic agonists commonly cause synaesthetic experiences and can also intensify existing synaesthesia in those who have the congenital form. The findings suggest that the serotonergic system plays a key role in the neurobiology of synaesthesia, offering a pathway to understand broader questions about consciousness and how the brain binds sensory information.
Drug Science Policy and Law
September 1, 2025
David Nutt, David Erritzøe, Anne Katrin Schlag et al.
9 citations
The field of psychedelic research lacks standardized terminology for clinical development, dosing, safety monitoring, and regulatory classification. A comprehensive framework is proposed that classifies psychedelics by pharmacology (serotonergic, glutamatergic, kappaergic, GABAergic, and atypical), introduces dose-dependent categories (microdose, minidose, mididose, macrodose), and standardizes terms like “short-acting” with specific pharmacokinetic parameters. Safety considerations include cardiovascular and psychological effects, with risk mitigation protocols for higher-risk compounds like ibogaine. A three-phase treatment model—preparation, dosing, and integration—is recommended as a minimum standard. The lack of comparative research on psychotherapy modalities is identified as a critical gap.
Transpersonal Psychology Review
January 1, 2020
Freya Harrild, David Luke
9 citations
This paper examines transpersonal psychology and ecopsychology together, focusing on their relationship with mystical experiences and the effects of nature-induced mystical experiences on ego-boundaries and psychological wellbeing. It argues that the re-emerging study of psychedelics—as positive agents for mental health, wellbeing, spiritual and creative growth, and social change—belongs inherently to a transpersonal ecopsychology. The paper concludes with a critical evaluation of these concepts and their implications for modern psychology.
Time and Mind
January 1, 2011
David Luke
6 citations
The article examines the ritual use of ayahuasca in Brazil, tracing its historical and cultural significance within indigenous and syncretic religious contexts. It describes how ayahuasca, a psychoactive brew, is employed in ceremonies to facilitate spiritual insight, healing, and community bonding. The text highlights the continuity of these practices from pre-colonial times to contemporary urban settings, noting their adaptation and legal recognition in Brazil. It argues that ayahuasca rituals represent a form of embodied knowledge and cultural heritage, challenging Western dichotomies between nature and culture, and between the sacred and the secular.
May 31, 2021
Jessica Sophie Corneille, David Luke
4 citations
preprint
Spontaneous spiritual awakenings (SSAs) are sudden experiences of merging with ultimate reality, the universe, or the divine. This study compared SSAs to spontaneous kundalini awakenings (SKAs), which the authors hypothesized might involve more physical and negative effects. In 152 participants, SKAs were significantly more physical and negative than SSAs, yet both were overwhelmingly positive overall. The phenomenological patterns of both experiences resembled other altered states of consciousness, especially drug-induced states from classic psychedelics like DMT and psilocybin. Personality traits absorption and temporal lobe lability predicted these awakening experiences.
International Journal of Transpersonal Studies
December 31, 2024
Pascal Michael, David Luke, Oliver Robinson
3 citations
Two individuals who had both a near-death experience (NDE) and an experience with changa (a smoked mixture of DMT and MAOI-containing plants) reported medium to high perceived similarity between the two states. One case (SR) had an NDE from a misaligned vertebra and rated his changa experience as highly similar, though only 36% of specific features matched his NDE; however, his changa experience shared 83% of features with NDEs in general. The other case (DA), whose NDE began from an allergic reaction, reported medium similarity, with 42% feature overlap with his own NDE and also 83% similarity with NDEs generally. Content differences were typically DMT-like, but the sequence and presence of many features closely resembled NDEs.
Psychoactives
March 4, 2025
Nadine Loh, David Luke
2 citations
Eight adults with chronic eating disorders (mean age of onset 13) reported their experiences with psychedelics in naturalistic and clinical settings. Seven of the eight reported lasting cessation or reduction of eating disorder symptoms, with two attributing full recovery to psychedelic use. Two participants relapsed months later due to environmental factors. Thematic analysis identified two overarching themes: 'Exploring' as a 'gateway to healing' covering mental, emotional, and transcendental aspects of the experience, and 'Transformation' enabling cognitive and behavioral changes alongside retrospective safety perceptions. The findings offer detailed insights into potential benefits and risks of psychedelic experiences for people with eating disorders and may guide future research into psychedelic-assisted therapy.
Frontiers in psychology
January 1, 2025
Pascal Michael, David Luke, Oliver Robinson
2 citations
A thematic and content analysis comparing naturalistic DMT experiences with near-death experiences (NDEs) found that DMT shares a basic phenomenological structure with NDEs, including canonical themes such as translocation, bright lights, sense of dying, the void, disembodiment, tunnel-like structures, light beings, deceased family, life review-like experiences, and hyper-empathic experiences. 95% of DMT participants reported at least one such theme. However, five classical NDE features were entirely absent from DMT, and DMT exhibited a broader array of features not present in NDEs. The two experiences diverge at a more nuanced qualitative level, with DMT being more prodigious, kaleidoscopic, and stereotypical. A minority of NDEs share significant content with DMT. The authors suggest DMT could be considered an 'NDE-mimetic' and discuss potential clinical applications.