Brain and Behavior
July 1, 2025
Megan Calnan, Grace Blest‐hopley, Chris Busch et al.
4 citations
Military veterans who attended psilocybin or ayahuasca retreats showed significant improvements in eight measures of mental health and community reintegration, with the largest gains in depression (29.1% reduction on the PHQ-9) and PTSD (26.1% reduction on the PCL-5). Psilocybin retreats produced greater improvements on seven of eight outcomes, while ayahuasca retreats yielded slightly larger PTSD reductions (26.4% vs. 24.8%). Male participants improved more on all outcomes except PTSD, where females showed a larger reduction (32.1% vs. 24.1%). Veterans with worse initial symptoms benefited most. The findings suggest psychedelic retreats could offer a holistic treatment framework addressing psychological well-being, community factors, and civilian reintegration.
Frontiers in Psychiatry
August 6, 2025
Grace Blest‐hopley, Giuseppe Pasculli, Simon Ruffell et al.
3 citations
Veterans with traumatic brain injuries who participated in psilocybin retreats showed improvements in PTSD, depression, and anxiety symptoms four weeks afterward. PTSD scores decreased by 50%, depression scores by 65%, and anxiety scores by 28%. Electroencephalography measurements revealed decreased delta and theta brainwave power in frontal and temporal regions, along with enhanced coherence in alpha and beta bands, suggesting improved cognitive control, emotional processing, and neural communication. The preliminary findings provide a rationale for larger controlled studies.
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.
bioRxiv (Cold Spring Harbor Laboratory)
November 3, 2021
Brandon Gunasekera, Cathy Davies, Grace Blest‐hopley et al.
preprint
A single dose of delta-9-tetrahydrocannabinol (THC) alters brain activation signals in a widespread network of regions, with some areas showing increased and others decreased activity. The magnitude of these changes is directly related to the local expression of the cannabinoid type-1 (CB1) receptor, but not the type-2 (CB2) receptor. THC increased activation in the anterior cingulate, superior frontal cortices, middle temporal and occipital gyri, striatum, amygdala, thalamus, and cerebellum crus II, while decreasing it in the middle temporal gyrus, superior temporal gyrus, angular gyrus, precuneus, cuneus, inferior parietal lobule, and cerebellum lobule IV/V. A dose-response relationship was observed in certain brain regions.