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Lysia Demetriou

7 papers in the library · 1,170 citations · publishing 2017-2025

Papers

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Reduced Brain Responsiveness to Emotional Stimuli With Escitalopram But Not Psilocybin Therapy for Depression

American Journal of Psychiatry May 7, 2025 Matthew B. Wall, Lysia Demetriou, Bruna Giribaldi et al. 16 citations

Despite large improvements in depressive symptoms in the psilocybin group, psilocybin therapy had only a minor effect on brain responsiveness to emotional stimuli. These results are consistent with prior findings that the antidepressant action of SSRIs is often accompanied by a reduction in emotional responsiveness, but this effect may not occur in psychedelic therapy.

Individual and combined effects of cannabidiol and Δ 9 -tetrahydrocannabinol on striato-cortical connectivity in the human brain

Journal of Psychopharmacology May 20, 2022 Matthew B. Wall, Tom P. Freeman, Chandni Hindocha et al. 21 citations

Background: Cannabidiol (CBD) and Δ 9 -tetrahydrocannabinol (THC) are the two major constituents of cannabis with contrasting mechanisms of action. THC is the major psychoactive, addiction-promoting, and psychotomimetic compound, while CBD may have opposite effects. The brain effects of these drugs alone and in combination are poorly understood. In particular, the striatum is implicated in the...

Individual and combined effects of Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) on striato-cortical connectivity in the human brain

bioRxiv (Cold Spring Harbor Laboratory) November 21, 2020 Matthew B. Wall, Tom P. Freeman, Chandni Hindocha et al. 4 citations preprint

Abstract Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are two major constituents of cannabis with contrasting mechanisms of action. THC is the major psychoactive, addiction-promoting, and psychotomimetic compound, while CBD may have somewhat opposite effects. The brain effects of these drugs alone and in combination are poorly understood. In particular the striatum is implicated in the...

Therapeutic mechanisms of psilocybin: Changes in amygdala and prefrontal functional connectivity during emotional processing after psilocybin for treatment-resistant depression

Journal of Psychopharmacology January 16, 2020 Lea J. Mertens, Matthew B. Wall, Leor Roseman et al. 211 citations

Background: Psilocybin has shown promise as a treatment for depression but its therapeutic mechanisms are not properly understood. In contrast to the presumed actions of antidepressants, we recently found increased amygdala responsiveness to fearful faces one day after open-label treatment with psilocybin (25 mg) in 19 patients with treatment-resistant depression, which correlated with...

Dissociable effects of cannabis with and without cannabidiol on the human brain’s resting-state functional connectivity

Journal of Psychopharmacology April 23, 2019 Matthew B. Wall, Rebecca Pope, Tom P. Freeman et al. 89 citations

BACKGROUND: -tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the main psychoactive component; CBD may buffer the user against the harmful effects of THC. AIMS: We examined the effects of two strains of cannabis and placebo on the human brain's resting-state networks using fMRI. METHODS: Seventeen healthy volunteers (experienced with cannabis, but not regular users) underwent three drug...

Increased amygdala responses to emotional faces after psilocybin for treatment-resistant depression.

Neuropharmacology December 27, 2017 Leor Roseman, Lysia Demetriou, Matthew B. Wall et al. 239 citations

Recent evidence indicates that psilocybin with psychological support may be effective for treating depression. Some studies have found that patients with depression show heightened amygdala responses to fearful faces and there is reliable evidence that treatment with SSRIs attenuates amygdala responses (Ma, 2015). We hypothesised that amygdala responses to emotional faces would be altered...

Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms.

Sci Rep October 13, 2017 Robin Carhart-Harris, Leor Roseman, Mark Bolstridge et al. 590 citations

Psilocybin with psychological support is showing promise as a treatment model in psychiatry but its therapeutic mechanisms are poorly understood. Here, cerebral blood flow (CBF) and blood oxygen-level dependent (BOLD) resting-state functional connectivity (RSFC) were measured with functional magnetic resonance imaging (fMRI) before and after treatment with psilocybin (serotonin agonist) for...