Improved mental health outcomes and normalized spontaneous EEG activity in veterans reporting a history of traumatic head injuries following participation in a psilocybin retreat
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Type
Journal Article
Abstract
Introduction: Psilocybin, a serotonergic psychedelic, has shown therapeutic potential in treating mental health disorders by, amongst the many effects, promoting neuroplasticity and reorganising functional connectivity across cortical and subcortical networks involved in emotion and cognition. Veterans with traumatic brain injuries (TBI) often experience chronic neurological and psychological symptoms such as post-traumatic stress disorder (PTSD) and depression. This study investigates the effects of psilocybin administered in retreat settings on veterans with a history of TBI, focusing on mental health outcomes and changes in brain connectivity as measured by EEG.
Methods: A total of 21 participants were recruited through the Heroic Hearts Project, which facilitated access to two six-day psilocybin retreats in Jamaica. Before the retreat, participants underwent three individual and three group coaching sessions to prepare for the experience. During the retreat, two psilocybin ceremonies were held, spaced 48 hours apart. Participants received an initial dose of 1.5g to 3.5g of dried psilocybin mushrooms, with the option to increase the second dose up to 5g. Psilocybin was administered in a tea format, under the supervision of experienced facilitators. Psychological outcomes were assessed using validated questionnaires (PCL-5, PHQ-9, STAI) at baseline (four weeks pre-retreat) and four weeks post-retreat. Electroencephalography (EEG) was used to measure brainwave activity pre- and post-treatment. Paired t-tests were used to analyze changes in psychological scores, while EEG frequency band analysis assessed changes in brain function and connectivity.
Results: Improvements were observed across several mental health measures: PTSD (PCL-5 scores decreased by 50%, p=0.010), depression (PHQ-9 scores decreased by 65%, p<0.001), and anxiety (STAI) scores decreased by 28%, p<0.001). EEG data showed decreased delta and theta power in frontal and temporal regions, indicating potential improvements in cognitive control and emotional processing. Enhanced coherence in alpha and beta bands suggested improved neural communication.
Discussion: The study suggests that psilocybin retreats might provide improvements in psychological well-being and brain connectivity in veterans with TBI. Reduced delta power and normalised theta activity suggest better emotional regulation, while improved coherence in alpha and beta bands may reflect increased cognitive engagement. Further, these preliminary outcomes provide a potential rationale for the design and implementation of larger-scale, controlled studies to validate and expand upon these initial findings.
Methods: A total of 21 participants were recruited through the Heroic Hearts Project, which facilitated access to two six-day psilocybin retreats in Jamaica. Before the retreat, participants underwent three individual and three group coaching sessions to prepare for the experience. During the retreat, two psilocybin ceremonies were held, spaced 48 hours apart. Participants received an initial dose of 1.5g to 3.5g of dried psilocybin mushrooms, with the option to increase the second dose up to 5g. Psilocybin was administered in a tea format, under the supervision of experienced facilitators. Psychological outcomes were assessed using validated questionnaires (PCL-5, PHQ-9, STAI) at baseline (four weeks pre-retreat) and four weeks post-retreat. Electroencephalography (EEG) was used to measure brainwave activity pre- and post-treatment. Paired t-tests were used to analyze changes in psychological scores, while EEG frequency band analysis assessed changes in brain function and connectivity.
Results: Improvements were observed across several mental health measures: PTSD (PCL-5 scores decreased by 50%, p=0.010), depression (PHQ-9 scores decreased by 65%, p<0.001), and anxiety (STAI) scores decreased by 28%, p<0.001). EEG data showed decreased delta and theta power in frontal and temporal regions, indicating potential improvements in cognitive control and emotional processing. Enhanced coherence in alpha and beta bands suggested improved neural communication.
Discussion: The study suggests that psilocybin retreats might provide improvements in psychological well-being and brain connectivity in veterans with TBI. Reduced delta power and normalised theta activity suggest better emotional regulation, while improved coherence in alpha and beta bands may reflect increased cognitive engagement. Further, these preliminary outcomes provide a potential rationale for the design and implementation of larger-scale, controlled studies to validate and expand upon these initial findings.
Date Issued
2025-08-06
Date Acceptance
2025-07-01
Citation
Frontiers in Psychiatry, 2025, 16
ISSN
1664-0640
Publisher
Frontiers Media S.A.
Journal / Book Title
Frontiers in Psychiatry
Volume
16
Copyright Statement
© 2025 Blest-Hopley, Pasculli, Ruffell, Tsang, Emmanuel, Pate, Kettner, Roseman, Erritzoe and Carhart-Harris. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
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Publication Status
Published
Article Number
1594307
Date Publish Online
2025-08-06