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David Erritzøe

Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Imperial College London, London, UK.

59 papers in the library · 6,061 citations · publishing 2011-2026

Papers

A Bayesian Reanalysis of a Trial of Psilocybin versus Escitalopram for Depression

June 30, 2022 Sandeep M. Nayak, Bilal A. Bari, David B. Yaden et al. 1 citation preprint

A Bayesian reanalysis of a trial comparing psilocybin (COMP360) to escitalopram for major depressive disorder found that psilocybin outperformed escitalopram, but not by a clinically meaningful amount. The analysis also found extremely strong evidence that psilocybin is non-inferior to escitalopram. Evidence for psilocybin's superiority varied by depression scale: indeterminate for one, strong for two, and extremely strong for another. For a clinically meaningful difference, evidence was moderate against it on one scale, indeterminate on two, and moderate supporting it on one. These results provide a more nuanced interpretation and support further research.

Psychedelics and Health Behavior Change - Journal of Psychopharmacology (in press)

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.

Author response: Self-blinding citizen science to explore psychedelic microdosing

December 11, 2020 Balázs Szigeti, Laura Kärtner, Allan Blemings et al. 1 citation

A self-blinding citizen science study tested whether psychedelic microdosing improves well-being and cognition beyond placebo. 191 participants who already planned to microdose were randomly assigned to receive four weeks of microdoses, placebos, or a mix. All psychological outcomes—including well-being, mindfulness, and life satisfaction—improved from baseline in the microdose group, but the placebo group also improved, and no significant differences emerged between groups. Small acute differences in mood, energy, and creativity were observed, but these could be explained by participants correctly guessing whether they took a microdose. The findings suggest that the anecdotal benefits of microdosing are likely due to the placebo effect.

Divergent changes in perturbation-induced brain reconfiguration following depression treatment with psilocybin and escitalopram

bioRxiv (Cold Spring Harbor Laboratory) June 26, 2026 Paulina Clara Dagnino, Irene Acero-Pousa, Robin Carhart‐Harris et al.

A central challenge in neuroscience is understanding how the human brain is organised to support optimal functioning and adaptability. One approach to characterise complex brain dynamics is by artificially perturbing whole-brain models. Here, we asked whether whole-brain organisation under perturbation in major depressive disorder (MDD) changes after intervention with psilocybin and escitalopram. First, we built whole-brain models of pre- and post-treatment resting-state functional magnetic resonance imaging (fMRI) and obtained an initial generative effective connectivity (GEC) matrix for each individual.

Sex-Specific Effects of Psilocybin Versus Escitalopram on Anxiety and Anhedonia: A Bayesian Reanalysis of Antidepressant Treatment Outcomes

Research Square June 19, 2026 Aline Frick, Grace Blest‐hopley, Manesh Grin et al.

In a reanalysis of a six-week randomized controlled trial comparing psilocybin with escitalopram for moderate-to-severe major depressive disorder, sex-related patterns emerged for anxiety and anhedonia. Women receiving psilocybin showed greater reductions in anxiety than men, while women receiving escitalopram showed greater reductions in anhedonia than men. For other depressive symptoms, thought suppression, and well-being, sex differences were small and uncertain. Sexual dysfunction severity was lower overall in the psilocybin group than in the escitalopram group and lower in women than in men, though the treatment-by-sex interaction was not significant. These preliminary findings suggest that responses to these serotonergic treatments may differ between women and men, supporting the need for adequately powered, sex-balanced trials.

Negative affective bias in depression following treatment with psilocybin or escitalopram – a secondary analysis from a randomized trial

Translational Psychiatry November 13, 2025 Bruna Giribaldi Cunha, David Nutt, Marieke Martens et al.

In a double-blind randomized trial, patients with long-standing moderate-to-severe depression received either two doses of 25 mg psilocybin plus daily placebo or two doses of 1 mg psilocybin plus daily escitalopram over six weeks. Both treatments comparably reduced negative bias in recognizing facial emotions, a measure of emotional information processing. However, changes in this bias were not linked to concurrent depression score changes. Only in the escitalopram group did a decrease in misclassifying positive faces as negative correlate with lower depression scores at a one-month follow-up. The findings suggest overlapping cognitive mechanisms between psilocybin and escitalopram, notable given psilocybin's short dosing regimen.

Human brain changes after first psilocybin use

October 14, 2024 Terence J. Lyons, Merle Spriggs, Leevi Kerkelä et al. preprint

A single high dose of psilocybin (25 mg) produced lasting functional and anatomical brain changes in healthy, psychedelic-naive adults, detected from one hour to one month later. Diffusion imaging showed decreased axial diffusivity in prefrontal-subcortical tracts, correlating with reduced brain network modularity, which in turn correlated with improved well-being. Increased cortical signal entropy shortly after dosing predicted better psychological well-being at one month, with next-day psychological insight mediating this relationship. No such effects occurred with a 1 mg placebo dose. Cognitive flexibility, psychological insight, and well-being also increased at one month.

Microdosing psychedelics: More questions than answers? An overview and suggestions for future research

Journal of Psychopharmacology July 14, 2019 Livia Ng, Luca Pani, Anaïs Soula et al.

Claims about the positive effects of microdosing psychedelics on mood and cognition have entered public discussion, but scientific studies are scarce and no consensus on what microdosing means exists. This critique identifies questions future research must answer and offers guidelines, focusing on psilocybin due to its potential clinical approval and short-lasting effects. While anecdotal reports emphasize benefits, the paper concludes that future studies should also investigate potential risks of repeated low-dose administrations. Preclinical and clinical research examining biological measures like heart rate and receptor turnover, as well as cognitive parameters such as memory and attention, is needed to uncover possible negative consequences.