Christopher Timmermann

Christopher Timmermann
Imperial College London | Imperial · Division of Brain Sciences

PhD

About

83
Publications
63,084
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2,801
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Introduction
Christopher Timmermann currently works at the Psychedelic Research Group in Imperial College London. He is currently leading a study involving the effects of DMT in the human brain and experience.

Publications

Publications (83)
Preprint
Full-text available
Psychedelics profoundly alter subjective experience and brain dynamics. Brain oscillations express signatures of near-critical dynamics, relevant for healthy function. Alterations in the proximity to criticality have been suggested to underlie the experiential and neurological effects of psychedelics. Here, we investigate the effects of a psychedel...
Preprint
The potential of meditation as a preparatory tool for psychedelic experiences lacks empirical investigation. We surveyed experienced practitioners (N=123) with substantial histories in both meditation and psychedelic use to examine meditation’s role in psychedelic preparation. Respondents expected meditation training to primarily enhance acceptance...
Preprint
DMT reliably induces profound experiences of immersion in other worlds and encounters with seemingly autonomous presences, yet the lived qualities and unfolding of these experiences remain poorly understood. Using micro-phenomenological interviews with twenty-three healthy participants who received DMT during fMRI scanning, this study explores how...
Preprint
Full-text available
It has been proposed that psychedelics induce profound functional changes to the hierarchical organisation of the human brain. Yet the term hierarchy is currently not well defined in neuroscience. Here, we use a precise definition of hierarchy, grounded in the theory of thermodynamics, which allows the quantification of temporal asymmetry in the di...
Preprint
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How is language related to consciousness? Language functions to categorise perceptual experiences (e.g., labelling interoceptive states as 'happy') and higher-level constructs (e.g., using 'I' to represent the narrative self). Psychedelic use and meditation might be described as altered states that impair or intentionally modify the capacity for li...
Article
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Background Psilocybin therapy (PT) produces rapid and persistent antidepressant effects in major depressive disorder (MDD). However, the long-term effects of PT have never been compared with gold-standard treatments for MDD such as pharmacotherapy or psychotherapy alone or in combination. Methods This is a 6-month follow-up study of a phase 2, doub...
Article
Background Non-ordinary states of consciousness induced by psychedelics can be accompanied by so-called “peak experiences,” characterized at the emotional level by their intensity and positive valence. These experiences are strong predictors of positive outcomes following psychedelic-assisted therapy, and it is therefore important to better underst...
Article
Full-text available
Psychedelics are recognised for their potential to re-orient beliefs. We propose a model of how psychedelics can, in some cases, lead to false insights and thus false beliefs. We first review experimental work on laboratory-based false insights and false memories. We then connect this to insights and belief formation under psychedelics using the ac...
Article
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Mystical-like states of consciousness may arise through means such as psychedelic substances, but may also occur unexpectedly during near-death experiences (NDEs). So far, research studies comparing experiences induced by serotonergic psychedelics and NDEs, along with their enduring effects, have employed between-subject designs, limiting direct co...
Preprint
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Exploring the intricate relationship between brain's structure and function, and how this affects subjective experience is a fundamental pursuit in neuroscience. Psychedelic substances offer a unique insight into the influences of specific neurotransmitter systems on perception, cognition and consciousness. Specifically, their impact on brain funct...
Article
The human brain is a complex system, whose activity exhibits flexible and continuous reorganisation across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over...
Preprint
Full-text available
Non-ordinary states of consciousness induced by psychedelics can be accompanied by so-called peak experiences, characterized at the emotional level by their intensity and positive valence. These experiences are strong predictors of positive outcomes following psychedelic-assisted therapy, and it is therefore important to better understand their bio...
Preprint
Full-text available
N,N-Dimethyltryptamine (DMT) is a serotonergic psychedelic, known to rapidly induce short-lasting alterations in conscious experience, characterized by a profound and immersive sense of physical transcendence alongside rich and vivid auditory distortions and visual imagery. Multimodal neuroimaging data paired with dynamic analysis techniques offer...
Article
Full-text available
Psilocybin, a serotonergic psychedelic, is being increasingly researched in clinical studies for the treatment of psychiatric disorders. The relatively lengthy duration of oral psilocybin’s acute effects (4–6 h) may have pragmatic and cost-effectiveness limitations. Here, we explored the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT), a c...
Preprint
The transition towards the brain state induced by psychedelic drugs is frequently neglected in favor of a static description of their acute effects. We used a time-dependent whole-brain model to reproduce large-scale brain dynamics measured with fMRI from 15 volunteers under 20 mg of bolus intravenous N,N-Dimethyltryptamine (DMT), a short-lasting p...
Article
Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes, such as personality changes. These findings are particularly intriguing, given that a decrease of brain entropy is a robust indicator of loss o...
Article
Full-text available
Background Due to their potential impact on mood and wellbeing there has been increasing interest in the potential of serotonergic psychedelics such as N,N-dimethyltryptamine (DMT) in the treatment of major depressive disorder (MDD). Aim The aim of Part A of this study was to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodyn...
Preprint
Full-text available
A growing body of work shows that autonomic signals provide a privileged evidence stream to capture various aspects of subjective and neural states. This work investigates the potential for autonomic markers to track the effects of psychedelics - potent psychoactive drugs with important scientific and clinical value. For this purpose, we introduce...
Article
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 me...
Article
Integrating independent but converging lines of research on brain function and neurodevelopment across scales, this article proposes that serotonin 2A receptor (5-HT2AR) signaling is an evolutionary and developmental driver and potent modulator of the macroscale functional organization of the human cerebral cortex. A wealth of evidence indicates th...
Article
Full-text available
N,N‐dimethyltryptamine (DMT) is a psychedelic compound that is being studied as a therapeutic option in various psychiatric disorders. Due to its short half‐life, continuous infusion of DMT has been proposed to extend the psychedelic experience and potential therapeutic effects. The primary aim of this work was to design an infusion protocol for DM...
Preprint
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Experiences of collective creative activities play an essential role in human societies, yet these experiences are particularly hard to capture, making their scientific scrutiny extremely challenging. Here we investigate the experience of audience members during a musical concert associated with collective improvisation by analysing the audience's...
Preprint
Full-text available
The human brain is a complex system, whose activity exhibits flexible and continuous reorganisation across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over...
Article
Full-text available
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 nat...
Article
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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 f...
Preprint
Full-text available
Psychedelics are recognised for their therapeutic potential and ability to re-orient beliefs. However, the prospect that psychedelics can induce false or maladaptive beliefs has been under- considered. Here, we review experimental work on false insights and false memories. We then connect this to insights and belief formation under psychedelics usi...
Poster
Full-text available
Psychedelic survey research in predominantly white, middle-to-upper class English-speaking participants suggests that naturalistic psychedelic use is associated with positive perceived effects on mental health conditions. Little is known about what benefits Spanish-speaking users experience from the use of psychedelic drugs or the strategies they u...
Poster
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Previous research on harm reduction (HR) strategies related to psychedelic use has been limited to primarily white, middle-to-upper class, English-speaking participants, finding a relationship between HR strategy use and acute psychedelic effects. However, nothing is known about the relationship between HR strategy use and acute psychedelic effects...
Article
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To understand how pharmacological interventions can exert their powerful effects on brain function, we need to understand how they engage the brain's rich neurotransmitter landscape. Here, we bridge microscale molecular chemoarchitecture and pharmacologically induced macroscale functional reorganization, by relating the regional distribution of 19...
Preprint
Full-text available
Psychedelics offer a profound window into the functioning of the human brain and mind through their robust acute effects on perception, subjective experience, and brain activity patterns. In recent work using a receptor-informed network control theory framework, we demonstrated that the serotonergic psychedelics lysergic acid diethylamide (LSD) and...
Article
Full-text available
Psychedelics have attracted medical interest, but their effects on human brain function are incompletely understood. In a comprehensive, within-subjects, placebo-controlled design, we acquired multimodal neuroimaging [i.e., EEG-fMRI (electroencephalography-functional MRI)] data to assess the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT)...
Article
Full-text available
N,N-dimethyltryptamine (DMT) is a psychedelic substance and is being used as a research tool in investigations of the neurobiology behind the human consciousness using different brain imaging techniques. The effects of psychedelics have commonly been studied using EEG and have been shown to produce suppression of alpha power and increase in signal...
Article
Full-text available
No contemporary unifying framework has been provided for the study of non-ordinary states of consciousness (NSCs) despite increased interest in hypnosis, meditation, and psychedelics. NSCs induce shifts in experiential contents (what appears to the experiencer) and/or structure (how it appears). This can allow the investigation of the plastic and d...
Article
This theoretical article revives a classical bridging construct, canalization, to describe a new model of a general factor of psychopathology. To achieve this, we have distinguished between two types of plasticity, an early one that we call 'TEMP' for 'Temperature or Entropy Mediated Plasticity', and another, we call 'canalization', which is close...
Article
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Background Psilocybin is a serotonin type 2A (5-HT 2A ) receptor agonist and naturally occurring psychedelic. 5-HT 2A receptor density is known to be associated with body mass index (BMI), however, the impact of this on psilocybin therapy has not been explored. While body weight-adjusted dosing is widely used, this imposes a practical and financial...
Article
Full-text available
Psychedelics are a unique class of drug which commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterised by increased temporal coherence at rest have been termed the 'Default Mode Network' (DMN). The DMN has been the focus of numerous studies assessing i...
Article
Full-text available
Psychedelic drugs show promise as safe and effective treatments for neuropsychiatric disorders, yet their mechanisms of action are not fully understood. A fundamental hypothesis is that psychedelics work by dose-dependently changing the functional hierarchy of brain dynamics, but it is unclear whether different psychedelics act similarly. Here, we...
Article
Full-text available
N,N‐dimethyltryptamine (DMT) is a psychedelic compound that is believed to have potential as a therapeutic option in several psychiatric disorders. The number of clinical investigations with DMT is increasing. However, very little is known about the pharmacokinetic properties of DMT as well as any relationship between its exposure and effects. This...
Article
Full-text available
Schizophrenia and states induced by certain psychotomimetic drugs may share some physiological and phenomenological properties, but they differ in fundamental ways: one is a crippling chronic mental disease, while the others are temporary, pharmacologically-induced states presently being explored as treatments for mental illnesses. Building towards...
Article
Full-text available
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’ a...
Article
Full-text available
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 c...
Preprint
Aim: N,N-dimethyltryptamine (DMT) is a psychedelic compound under development for the treatment of major depressive disorder (MDD). This study evaluated the in vitro metabolism and clinical pharmacokinetics (PK) of DMT fumarate (SPL026) in healthy subjects. Methods: Results are from the Phase I component of an ongoing Phase I/IIa randomised, double...
Preprint
Full-text available
Background: 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. Methods: Qualitative analysis of all N, N-DMT experiences posted to the r/DMT Red...
Article
Full-text available
Psilocybin therapy shows antidepressant potential, but its therapeutic actions are not well understood. We assessed the subacute impact of psilocybin on brain function in two clinical trials of depression. The first was an open-label trial of orally administered psilocybin (10 mg and 25 mg, 7 d apart) in patients with treatment-resistant depression...
Article
A highly sensitive LC-MS/MS method for the quantification of N,N-dimethyltryptamine (DMT) and its metabolites indole-3-acetic acid and DMT N-oxide in human plasma has been developed and validated. Chromatography was performed using a diphenyl column with gradient elution (0.1% formic acid in methanol/water). The mass spectrometer was operated in mu...
Preprint
Full-text available
Schizophrenia and states induced by certain psychotomimetic drugs may share some physiological and phenomenological properties, but they differ in fundamental ways: one is a crippling chronic mental disease, while the others are temporary, pharmacologically-induced states presently being explored as treatments for mental illnesses. Building towards...
Article
Full-text available
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...
Article
Full-text available
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, c...
Article
Full-text available
Many people who have had a near-death experience (NDE) describe, as part of it, a disturbed sense of having a “distinct self”. However, no empirical studies have been conducted to explore the frequency or intensity of these effects. We surveyed 100 NDE experiencers (Near-Death-Experience Content [NDE-C] scale total score ≥27/80). Eighty participant...
Preprint
Are psychedelics able to induce lasting changes in metaphysical beliefs? While it is popularly believed that they can, this has never been systematically 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...
Article
Full-text available
Healthful behaviours such as maintaining a balanced diet, being physically active and refraining from smoking have major impacts on the risk of developing cancer, diabetes, cardiovascular diseases and other serious conditions. The burden of the so-called ‘lifestyle diseases’—in personal suffering, premature mortality and public health costs—is cons...
Article
Full-text available
Background: Mescaline is a naturally occurring psychoactive phenethylamine found in several cacti and historically used ceremonially by Indigenous and Latin American populations. Broader recognition of its possible therapeutic value in Western science began in the 1950s; however, knowledge of the safety profile of mescaline and the extent of its u...
Article
Full-text available
Background: Recent years have seen a resurgence of research on the potential of psychedelic substances to treat addictive and mood disorders. Historically and contemporarily, psychedelic studies have emphasized the importance of contextual elements ('set and setting') in modulating acute drug effects, and ultimately, influencing long-term outcomes....
Preprint
Healthful behaviors such as maintaining a balanced diet, being physically active, and refraining from smoking have major impacts on the risk of developing cancer, diabetes, cardiovascular diseases, and other serious conditions. The burden of the so-called “lifestyle diseases” - in personal suffering, premature mortality, and public health costs - i...
Article
Full-text available
Background: N,N-dimethyltryptamine is a short-acting psychedelic tryptamine found naturally in many plants and animals. Few studies to date have addressed the neural and psychological effects of N,N-dimethyltryptamine alone, either administered intravenously or inhaled in freebase form, and none have been conducted in natural settings. Aims: Our...
Article
Full-text available
Psychedelic microdosing describes the ingestion of near-threshold perceptible doses of classic psychedelic substances. Anecdotal reports and observational studies suggest that microdosing may promote positive mood and well-being, but recent placebo-controlled studies failed to find compelling evidence for this. The present study collected web-based...
Article
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A striking feature of psychedelics is their ability to increase attribution of truth and meaningfulness to specific contents and ideas experienced, which may persist long after psychedelic effects have subsided. We propose that processes underlying conferral of meaning and truth in psychedelic experiences may act as a double-edged sword: while thes...
Article
Full-text available
The regulatory role of the serotonergic system on conscious perception can be investigated perturbatorily with psychedelic drugs such as N,N-Dimethyltryptamine. There is increasing evidence that the serotonergic system gates prior (endogenous) and sensory (exogenous) information in the construction of a conscious experience. Using two generative de...
Article
Full-text available
Therapeutic psychedelic administration and contact with nature have been associated with the same psychological mechanisms: decreased rumination and negative affect, enhanced psychological connectedness and mindfulness-related capacities, and heightened states of awe and transcendent experiences, all processes linked to improvements in mental healt...
Preprint
Full-text available
Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes such as personality changes. These findings are particularly intriguing given that a decrease of brain entropy is a robust indicator of loss of...
Article
Full-text available
Psychedelic drugs are potent modulators of conscious states and therefore powerful tools for investigating their neurobiology. N,N, Dimethyltryptamine (DMT) can rapidly induce an extremely immersive state of consciousness characterized by vivid and elaborate visual imagery. Here, we investigated the electrophysiological correlates of the DMT induce...