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.
Imaging Neuroscience
April 16, 2025
Lorenzo Pasquini, Alexander J. Simon, Courtney L. Gallen et al.
1 citation
DMT rapidly induces a short-lasting altered state of consciousness marked by physical transcendence, vivid auditory distortions, and visual imagery. Using simultaneous fMRI and EKG data from 14 healthy volunteers before, during, and after intravenous DMT or placebo, a brain substate emerged immediately after DMT injection, characterized by deactivations in the hippocampus and medial parietal cortex and increased activity in the superior temporal lobe. Hippocampal and medial parietal deactivations correlated with altered 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.
International review of neurobiology
January 1, 2025
Kate Godfrey, Lisa X Luan, Christopher Timmermann
1 citation
Classic psychedelics like LSD, psilocybin, ayahuasca, and DMT consistently reduce alpha power (8-13 Hz) in occipital regions, as measured by resting-state EEG and MEG. Below 30 Hz, desynchronization is typical, though DMT can preserve or increase delta/theta activity. Measures of signal diversity, such as Lempel-Ziv complexity, reliably increase during psychedelic states, indicating more variable neural firing. Real-time subjective intensity and plasma levels robustly covary with spectral and complexity changes, suggesting potential for real-time EEG biomarkers. Limited research on functional connectivity and cortical travelling waves hints at decreased top-down control and increased bottom-up signaling, a possible transient reversal of hierarchical organization, but replications are needed. EEG has yet to be evaluated in clinical studies.
bioRxiv (Cold Spring Harbor Laboratory)
December 22, 2024
Jakub Vohryzek, Morten L. Kringelbach, Edmundo Lopez-Sola et al.
1 citation
preprint
Both psychedelic states and reduced states of consciousness flatten the brain's functional hierarchy, yet their behavioral and phenomenological profiles differ. To resolve this paradox, researchers defined hierarchy by the brain's proximity to thermodynamic equilibrium and examined changes induced by three serotonergic psychedelics: psilocybin, LSD, and DMT. All three consistently reduced the functional hierarchy globally. Unlike loss of consciousness, psychedelics moved the brain toward equilibrium while increasing neural activity complexity, indicating a distinct mechanism involving altered configuration and differentiation of resting-state networks. This work demonstrates how statistical mechanics metrics can characterize different global brain states, advancing understanding of consciousness as an emergent collective process.
CPT: pharmacometrics & systems pharmacology
October 1, 2023
Emma Eckernäs, Jeroen Koomen, Christopher Timmermann et al.
1 citation
A modeling study designed an infusion protocol for the psychedelic compound DMT, aiming to maintain a specific level of psychedelic intensity. Using computer simulations based on pharmacokinetic/pharmacodynamic models, optimal doses to achieve intensity ratings between 7 and 9 on a 0-10 scale were a bolus of 14-16 mg DMT fumarate followed by an infusion rate of 1.2-1.4 mg/min. However, the proportion of simulated individuals achieving the target intensity was low (below 53%), indicating that individual dose adjustments would be necessary. Differences between the models were observed, particularly at scale boundaries, with bounded integer models predicting more cases exceeding the target than the continuous variable model.
March 24, 2021
Pedro J. Teixeira, Matthew W. Johnson, Christopher Timmermann et al.
1 citation
preprint
Unhealthy behaviors like poor diet, inactivity, and smoking are major contributors to cancer, diabetes, and cardiovascular disease, causing substantial suffering and public health costs. Interventions to promote healthy behaviors increasingly draw on psychobiological models. This article explores the potential of psilocybin, a psychedelic with low toxicity and no addictive properties, to assist positive lifestyle change. Psilocybin has shown favorable effects in patients with depression, anxiety, and substance misuse, conditions marked by rigid behavioral patterns. The authors describe proposed mechanisms and research findings linking psychedelics to health behavior change, noting that therapeutic models combining psychedelic experiences with methods like Cognitive Behavior Therapy and Motivational Interviewing are already being tested for addiction and eating disorders. They suggest this research may extend to promoting diet, exercise, nature exposure, and mindfulness.
bioRxiv : the preprint server for biology
June 1, 2026
Panagiotis Fotiadis, Hyunwoo Jang, Rui Dai et al.
Brain waves coordinate neural communication and shape conscious perception. Analyzing blood oxygen level-dependent activity from the Human Connectome Project and other datasets across sleep, propofol anesthesia, and psychedelic states (LSD, DMT, psilocybin, nitrous oxide, ketamine), four dominant wave propagation motifs were identified: a global synchronized wave, an anti-correlated unimodal-transmodal wave, an anti-correlated task-positive/task-negative wave, and an anti-correlated visual-somatomotor wave.
BMJ open
March 12, 2026
Rosalind McAlpine, Magdalena Jaglinska, Krisztina Jedlovszky et al.
A 21-day mobile-accessible programme called the Digital Intervention for Psychedelic Preparation (DIPP) is being tested for feasibility and preliminary efficacy in a randomised controlled trial. The study will recruit 40 non-treatment-seeking adults without a clinical diagnosis, randomly assigning them to either a guided meditation with music condition or a music-only condition. After the digital intervention, all participants will attend an in-person supervised psilocybin session with a standardised 25 mg dose. Primary outcomes include recruitment efficiency, retention, and adherence; secondary outcomes assess preparedness, quality of the psychedelic experience, and wellbeing, with follow-ups up to 9 months. The trial is registered as NCT06815653.
Neuroscience of consciousness
January 1, 2026
Jonas Mago, George Deane, Lars Sandved-Smith et al.
People under the influence of psychedelics often report encountering autonomous entities such as spirits, elves, or ancestors. A neurocomputational model, grounded in the active inference framework, explains these experiences by proposing that psychedelics reduce the predictability of sensory perceptions, leading the brain to interpret both internal and external perceptions as coming from non-self agents. The model synthesizes earlier theories including the entropic brain model, computational accounts of felt presence, and sensory attenuation theories of self-other discrimination. It aims to account for how the brain supports entity encounters and for the diversity and similarity of these experiences across cultural contexts.
The Journal of neuroscience : the official journal of the Society for Neuroscience
November 24, 2025
Mona Irrmischer, Marco Aqil, Lisa Luan et al.
A psychedelic substance (DMT) shifts brain oscillations away from criticality—a state of balanced, complex activity—toward a quieter subcritical regime, particularly in alpha and adjacent frequency bands. This shift increases entropy while reducing complexity. The magnitude of the criticality shift in alpha and theta bands correlates with the intensity of self-dissolution, a core feature of the psychedelic experience. These findings suggest that altered proximity to critical dynamics underlies both the neurological and experiential effects of psychedelics, with implications for understanding altered states of consciousness.
Psychedelics
November 15, 2025
Meghan DellaCrosse, Shoval Gilead, Rafael Lancelotta et al.
Spanish-speaking individuals who had a memorable psilocybin or LSD experience reported two main themes: deep connection (to nature, others, the present moment, and the substance) and emotion-related experiences (from joy and peace to emotional processing, catharsis, and challenging experiences). The findings are based on a secondary qualitative analysis of open-ended survey responses from 379 Spanish-speaking participants. Similarities appeared across both substances, with some unique nuances. The work underscores the need for diverse populations in psychedelic research to improve generalizability and cultural relevance, and highlights the therapeutic potential of psychedelics while calling for culturally sensitive tools.
bioRxiv Preprint Server
June 12, 2026
Dante Sebastián Galván Rial, Gabriel A. Della Bella, Lorina Naci et al.
preprint
States of consciousness can be ordered along a single dimension defined by the entropy of spontaneous neural activity, as proposed by the Entropic Brain Theory. Applying the same analytical pipeline to pharmacological (psychedelics, modafinil, propofol anaesthesia) and clinical (schizophrenia) fMRI datasets, the temporal irregularity of brain network topology was quantified. Propofol anaesthesia occupied the low-entropy end; psychedelic states and schizophrenia occupied the high end. This ordering tracks combined modulations of the level and content of consciousness, from reduced awareness under anaesthesia to heightened arousal and expanded experience under psychedelics and disorganised processing in schizophrenia. The result was not reducible to fluctuations in mean functional connectivity and was supported by convergent reorganisation of higher-order association cortex.
Neuroscience of consciousness
January 1, 2026
James W Sanders, Raphaël Millière, Ema Demšar et al.
The psychedelic compound DMT induces highly immersive experiences that often include encounters with seemingly sentient presences. Using micro-phenomenology, immersion under DMT was characterized as a structured continuum from subtle to gross forms. Twenty-three participants received 20 mg intravenous DMT during fMRI-EEG, followed by detailed interviews. Analysis yielded 125 phenomenological categories describing structural dimensions like sensory faculties, spatial organization, and self-world configuration. Bodily effects typically preceded visual and auditory ones, and perceived presences emerged only after multisensory integration and 3D spatial characteristics had developed, illustrating a hierarchical relationship between subtle and gross immersion. Perceived presences varied widely in sensory modality, semantic complexity, and relational mode, showing immersion as a dynamic, constructive process.
arXiv Preprint Archive
March 28, 2025
Marcus J. Glennon, Catherine I. V. Bird, Prateek Yadav et al.
Setting up a psychedelic study is a long and complex process that presents unique challenges not yet standardized. This review brings together major UK research teams to formalize these considerations, identify ongoing debates, and provide a practical guide for researchers and policymakers. It addresses challenges to existing assumptions about psychiatric prescribing, the placebo effect, and definitions of selfhood. The paper can be read end-to-end or used as a manual with sections for specific needs.