July 3, 2023
Hugh McGovern, Hilary Jane Grimmer, Manoj K. Doss et al.
12 citations
preprint
Psychedelics can reorient beliefs, but they may also lead to false insights and false beliefs. A review of laboratory research on false insights and false memories is connected to belief formation under psychedelics through the active inference framework. Psychedelics increase both the quantity and subjective intensity of insights and beliefs, including false ones. Future research should aim to minimize the risk of false and potentially harmful beliefs arising from psychedelics. Understanding this risk is crucial for safely leveraging the therapeutic potential of psychedelics.
Neuroscience of Consciousness
January 1, 2024
Charlotte Martial, Robin Carhart-Harris, Christopher Timmermann
9 citations
People who have had both a near-death experience (NDE) and a psychedelic experience (PE) report overlapping mystical-like effects, such as feelings of unity and transcendence, and similar attributions of reality, psychological insights, and lasting changes. However, low-level sensory phenomena differ: NDEs involve stronger disembodiment, while psychedelics produce more visual imagery. The study used an online survey of 31 adults who had experienced both an NDE (scoring ≥27 on the NDE-C scale) and a PE with classic psychedelics. Bayesian and frequentist analyses confirmed these overlaps and differences, suggesting psychedelics can model the mystical aspects of NDEs but not their sensory features.
PsyArXiv
April 13, 2023
Lisa Xiaolu Luan, Emma Eckernäs, Michael Ashton et al.
9 citations
preprint
A within-subjects, placebo-controlled study tested a novel method of administering N,N-Dimethyltryptamine (DMT) by combining a bolus injection with a constant-rate infusion to extend the experience to 30 minutes. The method effectively maintained stable and tolerable subjective effects over the infusion period. Anxiety ratings remained low, and heart rate habituated within 15 minutes, indicating psychological and physiological safety. Plasma DMT concentrations increased consistently starting ten minutes into administration, while psychological effects plateaued, suggesting acute psychological tolerance to DMT. These findings demonstrate the safety and effectiveness of continuous intravenous DMT administration for basic and clinical research.
Psychopharmacology
May 1, 2018
Mendel Kaelen, Bruna Giribaldi, Jordan Raine et al.
9 citations
correction
Music plays a central role in psychedelic therapy by helping to guide and support the therapeutic process. The article synthesizes evidence that music can influence emotional states, facilitate psychological insights, and enhance the overall therapeutic outcome when combined with psychedelic substances. The authors argue that music acts as a "hidden therapist" by directing the trajectory of the psychedelic experience, promoting emotional release, and supporting the integration of the experience afterward. This suggests that careful selection and use of music is crucial for optimizing the therapeutic benefits of psychedelic therapy.
Nature Medicine
April 1, 2026
Manesh Girn, Manoj K. Doss, Leor Roseman et al.
8 citations
Psychedelic drugs are being studied again for their therapeutic potential, but how they change brain function is not well understood. By combining 11 brain-scanning datasets from five different psychedelics (psilocybin, LSD, mescaline, DMT, and ayahuasca) across three continents, researchers found a common pattern: increased communication between brain networks that handle high-level thinking (default, frontoparietal, and limbic) and those that handle sensory input (visual and somatomotor). Key deep-brain regions (thalamus, caudate, putamen) and the cerebellum also changed how they connect with sensorimotor networks. Contrary to some earlier studies, reductions in within-network connectivity were weak to moderate and varied by drug. These findings help resolve previous inconsistencies and provide a comprehensive map of how psychedelics alter large-scale brain organization.
bioRxiv (Cold Spring Harbor Laboratory)
May 31, 2024
Jakub Vohryzek, Selen Atasoy, Gustavo Deco et al.
8 citations
preprint
Psychedelic substances like DMT, psilocybin, LSD, and ketamine alter brain function by reshaping the repertoire of connectome harmonics—patterns of neural activity that depend on the brain's structural network of white matter pathways. Under DMT, the entropy of these harmonics increases, indicating a more diverse range of brain states. For the first time, changes in the energy spectrum and entropy of connectome harmonics were shown to track the intensity of subjective experience in real time, suggesting a close link between the brain's harmonic activity and conscious experience.
Communications biology
April 18, 2025
S Parker Singleton, Christopher Timmermann, Andrea I Luppi et al.
7 citations
After DMT injection, the brain requires less control energy to transition between states compared to placebo, indicating a more flexible and less constrained brain dynamic. These energy changes track with EEG signal diversity and subjective intensity of the drug experience. The regional pattern of DMT's effects aligns with serotonin 2a receptor density, and a model using receptor distribution and pharmacokinetics can predict the drug's impact on brain energy trajectories.
bioRxiv
August 21, 2023
Jakub Vohryzek, Joana Cabral, Christopher Timmermann et al.
7 citations
preprint
The brain's activity constantly reorganizes across space and time. A new framework called Harmonic Decomposition of Spacetime (HADES) was developed to track how spatial activity patterns (harmonic modes) change over time. As a proof-of-principle, HADES was applied to brain recordings from healthy participants under the psychedelic DMT and in a normal state. DMT significantly decreased contributions from most low-frequency harmonic modes. After normalizing by condition, a specific decrease appeared in the second functional harmonic, which represents the brain's hierarchy from unimodal to transmodal regions, supporting the hypothesis that psychedelics alter this functional hierarchy. Dynamic measures of fractional occupancy, lifetime, and latent space precisely described changes in the spacetime hierarchical organization of brain activity during the psychedelic state.
Elife
November 9, 2020
Andrea Alamia, Christopher Timmermann, David J Nutt et al.
7 citations
correction
No Summary
Communications biology
March 11, 2025
Juan Ignacio Piccinini, Yonatan Sanz Perl, Carla Pallavicini et al.
6 citations
The transition into a psychedelic brain state is often overlooked in favor of static descriptions of acute effects. Using a time-dependent whole-brain model and fMRI data from 15 volunteers given intravenous DMT, the work shows that a transient of heightened reactivity in fronto-parietal regions and visual cortices correlates with serotonin 5HT2a receptor density. Simulated perturbations suggest that minimal disturbances can achieve maximal effects during this brief period, and the temporal evolution of these features aligns with pharmacokinetics. These findings indicate a mechanism for how short psychedelic episodes may exert a lasting influence over time.
bioRxiv
March 20, 2024
Valerie Bonnelle, Amanda Feilding, Fernando E. Rosas et al.
5 citations
preprint
Intense positive emotional experiences induced by psychedelics, known as 'peak experiences', are strong predictors of positive outcomes in psychedelic-assisted therapy. This study investigated how the autonomic nervous system (ANS) relates to such experiences. Analyzing electrocardiogram data from 17 participants who received DMT or placebo, researchers found that coactivation of the sympathetic and parasympathetic branches of the ANS during the DMT experience was strongly correlated with ratings of 'Spiritual Experience' and 'Insightfulness', and also linked to improved wellbeing two weeks later. Additionally, the balance between these branches before DMT injection predicted 'Insightfulness' scores. These findings demonstrate the ANS's involvement in psychedelic-induced peak experiences and suggest potential for biofeedback tools to enhance therapy.
bioRxiv (Cold Spring Harbor Laboratory)
July 13, 2022
Andrea I. Luppi, Justine Y. Hansen, R. Adapa et al.
5 citations
preprint
Psychoactive drugs reshape brain function by engaging multiple neurotransmitter systems simultaneously. By mapping the distribution of 19 neurotransmitter receptors and transporters (via PET) and the connectivity changes caused by 10 drugs (anesthetics, psychedelics, and stimulants), the study shows that drug effects are organized along hierarchical gradients of brain structure and function. Additionally, brain regions susceptible to drug-induced changes are also vulnerable to structural alterations from brain disorders. These findings reveal systematic links between molecular neurochemistry and large-scale functional reorganization.
Nat Med
February 16, 2026
David Erritzøe, Tommaso Barba, Tiffanie Benway et al.
4 citations
A single 21.5-mg intravenous dose of the psychedelic DMT, given with psychotherapeutic support, produced a rapid and significant reduction in depressive symptoms in adults with moderate-to-severe major depressive disorder. In a double-blind, placebo-controlled trial with 34 participants, those receiving DMT showed a greater decrease in depression scores at two weeks compared to placebo. Antidepressant effects persisted up to three months in an open-label phase. Adverse events were mostly mild to moderate, and no serious adverse events occurred.
Journal of Psychedelic Studies
May 30, 2025
Esenia K. Cassidy, David Dupuis, Christopher Timmermann et al.
4 citations
Attachment patterns and psychedelic use jointly influence worldview transformations and enculturation processes. Both may operate through common mechanisms: heightened epistemic trust at the psychological level and heightened serotonin 2a receptor-binding with associated hyper-plastic states at the neural level. The synthesis draws on attachment-religion research, anthropological studies of Ayahuasca use in shamanic tourism, and preliminary attachment-psychedelics research. Future research directions and ethical considerations for psychedelic-assisted therapies and cross-cultural research are outlined.
PsyArXiv
May 14, 2025
James W. Sanders, Raphaël Millière, Ema Demšar et al.
4 citations
preprint
Under DMT, immersive experiences and perceived presences follow a consistent structural pattern: bodily sensations arise first, then visual and auditory elements, and only after multisensory integration and 3D spatial characteristics develop do perceived sentient presences emerge. Micro-phenomenological interviews with 23 participants who received intravenous DMT (20mg) during fMRI-EEG recordings identified 125 phenomenological categories structuring immersion, including modal sensory dimensions, amodal feelings, self/world configurations, and social engagement modes. Perceived presences varied in sensory manifestation, semantic complexity, and social interaction modes. The findings advance understanding of non-ordinary states of consciousness and support future neurophenomenological research.
bioRxiv
February 8, 2025
Mona Irrmischer, Marco Aqil, Lisa Luan et al.
4 citations
preprint
The psychedelic DMT shifts brain oscillations away from criticality—a state thought to support healthy brain function—in alpha and adjacent frequency bands, moving toward subcritical regimes. Entropy increases while complexity decreases during this shift. The magnitude of the criticality shift in alpha and theta bands correlates with the intensity of ego-dissolution, a core feature of the psychedelic experience. These results suggest that altered proximity to critical brain dynamics may underlie the neurological and subjective effects of psychedelics, with implications for understanding altered states of consciousness.
bioRxiv : the preprint server for biology
August 12, 2024
Lorenzo Pasquini, Alexander J Simon, Courtney L Gallen et al.
4 citations
preprint
The psychedelic DMT rapidly alters consciousness, producing physical transcendence, vivid auditory distortions, and visual imagery. Using simultaneous fMRI and EKG data from 14 healthy volunteers before, during, and after intravenous DMT (versus placebo), a brain substate emerged immediately after injection characterized by deactivations in the hippocampus and medial parietal cortex alongside increased superior temporal lobe activity. Hippocampal and medial parietal deactivations correlated with disruptions in the sense of time, space, and self-referential processes, reflecting a deconstruction of ordinary consciousness. Superior temporal lobe activations correlated with audio/visual hallucinations and the experience of "entities.
Journal of Psychoactive Drugs
July 14, 2023
Christopher Timmermann, Aki Nikolaidis, Alan K. Davis et al.
4 citations
Spanish translations of three questionnaires measuring acute psychedelic effects—the Psychological Insight Questionnaire (PIQ), Challenging Experiences Questionnaire (CEQ), and Mystical Experiences Questionnaire (MEQ)—showed good psychometric properties in a sample of 442 native Spanish speakers. Confirmatory factor analysis confirmed that the factor structures matched the original English versions, and this consistency held across subgroups who had used LSD or psilocybin. Construct validity was supported by positive associations between the PIQ and MEQ and between these measures and changes in cognitive fusion, alongside negative associations with changes in prosocial behaviors. Predictive validity was indicated by strong relationships between persisting effects and scores on the MEQ and PIQ. The Spanish versions can be reliably used in research with Spanish-speaking populations.
bioRxiv
July 18, 2019
Christopher Timmermann, Leor Roseman, Michael Schartner et al.
4 citations
preprint
Intravenous DMT, a fast-acting psychedelic, markedly alters human brain activity. Compared with a placebo, DMT reduced oscillatory power in alpha and beta brainwaves and increased spontaneous signal diversity. Time-referenced analyses linked changes in subjective experience to changes in brain activity. Emergence of delta and theta frequency oscillations correlated with the peak of the experience, particularly its eyes-closed visual component. These findings advance understanding of the neurobiological underpinnings of immersive states of consciousness.
Meghan Good, Tiffanie Benway, Zelah Joel et al.
4 citations
DMT (N,N-dimethyltryptamine) is being developed as a treatment for major depressive disorder. In a phase I trial, 24 healthy adults received escalating intravenous doses of DMT fumarate (SPL026) that were safe and well-tolerated. DMT exposure increased proportionally with dose over the 9–21.5 mg range. Peak plasma concentration occurred at about 10 minutes, and the mean elimination half-life was 9–12 minutes. In vitro experiments showed that DMT is cleared by monoamine oxidase A (MAO-A) and modified by the enzymes CYP2D6 and CYP2C19. The unbound fraction of DMT in plasma was approximately 70%. These findings support the development of DMT infusion regimens for treating major depressive disorder.
PsyArXiv
December 29, 2024
James W. Sanders, Raphaël Millière, Zachary G. Daily et al.
3 citations
preprint
DMT reliably produces profound experiences of immersion in other worlds and encounters with seemingly autonomous presences, but the lived qualities and unfolding of these experiences remain poorly understood. Micro-phenomenological interviews with twenty-three healthy participants who received DMT during fMRI scanning revealed rich dimensions of immersive experience—from multisensory engagement to radical reconfigurations of self and world—and illuminated varied ways presences can be seen, felt, or otherwise sensed. The analysis identified structural features and temporal dynamics, particularly the layering of sensory effects followed by spatial, self-related, and social effects, extending beyond traditional constructs like ego dissolution or mystical experience. This mapping advances understanding of DMT's effects and conscious experience, inviting comparisons with meditation, lucid dreaming, and presence phenomena in lab-induced hallucinations or Parkinson's disease.
Journal of psychoactive drugs
January 1, 2024
David Wyndham Lawrence, Alex P DiBattista, Christopher Timmermann
3 citations
Among 227 naturalistic DMT experiences that felt familiar, the familiarity was not attributed to a prior psychedelic experience. Most (97.4%) included features of a mystical experience, 16.3% involved ego-dissolution, and 11.0% a profound sense of death. A new questionnaire identified five themes of familiarity: feeling or knowledge gained; place or environment; the act of going through the experience; transcendent features; and familiarity imparted by an entity encounter. Two stable participant classes emerged: one class more often reported familiarity from an entity encounter and from the feeling or knowledge gained. The sense of familiarity during DMT appears non-referential to past psychedelic use.
Neuroscience and biobehavioral reviews
July 1, 2026
Marcus J Glennon, Catherine I V Bird, Prateek Yadav et al.
2 citations
Setting up a psychedelic research study involves a long, arduous, and Kafkaesque process with many unstandardised challenges. These complexities challenge existing assumptions about psychiatric prescribing, the placebo effect, and definitions of selfhood. This review brings together major UK psychedelic research teams to formalise these unique considerations, addressing sociocultural, political, legal, pharmacological, safety, study design, and experiential facets. It identifies continuing areas of debate and provides a practical, experience-based guide with recommendations for policymakers and future researchers intending to set up a psychedelic study or clinical trial.
December 4, 2025
Avery Ostrand, Matthew M. Nour, Christopher Timmermann et al.
2 citations
preprint
The term 'psychedelic' was coined in 1956 from Greek roots meaning 'soul-manifesting' or 'soul-illuminating,' intended to name a drug category defined by its ability to induce a characteristic subjective state. This study examined the main subjective effects of psilocybin, ketamine, and MDMA. Over two hundred participants rated items about their experiences with all three drugs. Factor analyses revealed three or four independent dimensions of subjective experience. A machine learning classifier successfully predicted which drug a person had taken from the effects reported, confirming that the three drugs produce categorically distinct experiences: psilocybin induces visions and psychological insight, ketamine induces dissociation, and MDMA induces pro-social feelings such as love. Psilocybin is thus an exemplar psychedelic drug, definable by its induction of a psychedelic state characterized by visions and insight.
Neuropsychopharmacology
September 12, 2025
Jakub Vohryzek, Andrea I. Luppi, Selen Atasoy et al.
2 citations
The brain's function depends on its structural wiring, and psychedelics alter this relationship. Using connectome harmonic decomposition, a method linking brain activity to the network of white matter pathways, the authors show that under N,N-dimethyltryptamine (DMT), the brain's harmonic repertoire shifts similarly to that seen with psilocybin, LSD, and ketamine. Repertoire entropy—a measure of the diversity of brain states—increases under DMT. For the first time, the energy spectrum difference and repertoire entropy of connectome harmonics track the intensity of subjective experience in real time, indicating a close coupling between brain network dynamics and conscious experience.