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Oliver Howes

12 papers in the library · 419 citations · publishing 2011-2025

Papers

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Receptor-enriched analysis of functional connectivity (REACT) for understanding cannabinoid neuropsychopharmacology

bioRxiv (Cold Spring Harbor Laboratory) June 5, 2025 Ekaterina Shatalina, Natalie Ertl, Kat Petrilli et al. 1 citation preprint

Abstract Background Cannabis is one of the most widely used psychoactive substances in the world and is increasingly investigated as a treatment for neuropsychiatric conditions. Cannabis contains delta-9-tetrahydrocannabinol (THC), which is thought to underlie its main psychoactive effects, and cannabidiol (CBD), which has been proposed to modulate the effects of THC on the brain. Both have...

N-Methyl-D-Aspartate Receptor availability in First-Episode Psychosis: a multi-modal PET-MR brain imaging study

European Psychiatry November 17, 2023 K. Beck, A. Arumuham, S. Brugger et al. 1 citation

Introduction N-Methyl-D-Aspartate Receptor (NMDAR) hypofunction is hypothesised to underlie psychosis but this has not been tested early in illness. Objectives Our aim was to determine if NMDAR availability was lower in patients with first episode psychosis compared to healthy controls. Methods To address this, we studied 40 volunteers (21 patients with first episode psychosis and 19 matched...

The drug treatment deadlock in psychiatry and the route forward

World Psychiatry January 14, 2023 Oliver Howes, Luke Baxter 16 citations

The US Food and Drug Administration (FDA) approved 12 new drugs in psychiatry during the decade 2011-2021 (www.fda.gov/drugs/drug-approvals-and-databases). In comparison, it approved 50 new drugs in neurology and 135 in oncology over the same period. The FDA designated two new drugs as first-in-class in psychiatry (lofexidine and brexanolone) in the most recent reviewed period (2015-2021),...

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...

Consensus paper of the WFSBP task force on cannabis, cannabinoids and psychosis

World Journal of Biological Psychiatry March 22, 2022 Deepak C. D’Souza, M. Diforti, Suhas Ganesh et al.

Abstract Objectives The liberalisation of cannabis laws, the increasing availability and potency of cannabis has renewed concern about the risk of psychosis with cannabis. Methods The objective of the WFSBP task force was to review the literature about this relationship. Results Converging lines of evidence suggest that exposure to cannabis increases the risk for psychoses ranging from...

N-methyl-D-aspartate receptor availability in first-episode psychosis: a PET-MR brain imaging study

Translational Psychiatry August 15, 2021 Katherine Beck, Atheeshaan Arumuham, Mattia Veronese et al.

Abstract N-methyl-D-aspartate receptor (NMDAR) hypofunction is hypothesised to underlie psychosis but this has not been tested early in illness. To address this, we studied 40 volunteers (21 patients with first-episode psychosis and 19 matched healthy controls) using PET imaging with an NMDAR selective ligand, [18F]GE-179, that binds to the ketamine binding site to index its distribution volume...

Association between age of cannabis initiation and gray matter covariance networks in recent onset psychosis

Neuropsychopharmacology March 3, 2021 Nora Penzel, Linda A. Antonucci, Linda T. Betz et al. 18 citations

Cannabis use during adolescence is associated with an increased risk of developing psychosis. According to a current hypothesis, this results from detrimental effects of early cannabis use on brain maturation during this vulnerable period. However, studies investigating the interaction between early cannabis use and brain structural alterations hitherto reported inconclusive findings. We...

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...

The acute effects of cannabidiol on the neural correlates of reward anticipation and feedback in healthy volunteers

Journal of Psychopharmacology August 5, 2020 Will Lawn, J. P. Hill, Chandni Hindocha et al. 23 citations

BACKGROUND: Cannabidiol has potential therapeutic benefits for people with psychiatric disorders characterised by reward function impairment. There is existing evidence that cannabidiol may influence some aspects of reward processing. However, it is unknown whether cannabidiol acutely affects brain function underpinning reward anticipation and feedback. HYPOTHESES: We predicted that cannabidiol...

History of cannabis use is not associated with alterations in striatal dopamine D 2 /D 3 receptor availability

Journal of Psychopharmacology September 2, 2011 Paul Stokes, Alice Egerton, Ben Watson et al. 62 citations

Cannabis use in adolescence is emerging as a risk factor for the development of psychosis. In animal studies, Δ9-tetrahydrocannabinol (THC), the psychoactive component of cannabis, modulates striatal dopaminergic neurotransmission. Alterations in human striatal dopaminergic function have also been reported both in psychosis and in stimulant use. We sought to examine whether striatal dopamine...