Addiction
February 16, 2026
Cassie Bloy, Ananya Sarma, Bethan Marsh et al.
1 citation
People with alcohol use disorder experience alterations in consciousness from 0.8 mg/kg intravenous ketamine administration. Ketamine's effects appear to be broadly consistent across three repeated infusions. Ketamine-related reductions in alcohol consumption do not appear to be mediated by the acute psychoactive effects of ketamine.
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...
The International Journal of Neuropsychopharmacology
February 1, 2025
Martine Skumlien, Tom P. Freeman, Daniel L. Hall et al.
Abstract Background Cannabis, and its main psychoactive compound tetrahydrocannabinol (THC), may alter the brain’ s reward system both acutely and over time. The endocannabinoid and reward systems mature during adolescence and adolescents may therefore respond differently to acute cannabis exposure compared with adults. Despite this, no previous functional magnetic resonance imaging (fMRI)...
Neuropsychopharmacology
May 28, 2024
Natalie Ertl, Tom P. Freeman, Claire Mokrysz et al.
19 citations
Adolescence is a time of rapid neurodevelopment and the endocannabinoid system is particularly prone to change during this time. Cannabis is a commonly used drug with a particularly high prevalence of use among adolescents. The two predominant phytocannabinoids are Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), which affect the endocannabinoid system. It is unknown whether this...
Psychopharmacology
February 28, 2024
Daniel L. Hall, Will Lawn, Shelan Ofori et al.
5 citations
RATIONALE: Attentional bias to drug-related stimuli is hypothesised to contribute towards addiction. However, the acute effects of Δ9-tetrahydrocannabinol (THC) on attentional bias to cannabis cues, the differential response in adults and adolescents, and the moderating effect of cannabidiol (CBD) are unknown. OBJECTIVES: Our study investigated (1) the acute effects of vaporised cannabis on...
Journal of Psychopharmacology
July 29, 2023
Natalie Ertl, Will Lawn, Claire Mokrysz et al.
17 citations
BACKGROUND/AIM: Cannabis use is highly prevalent in adolescents; however, little is known about its effects on adolescent brain function. METHOD: = 70, 35 adolescents/35 adults). Pre-registered analyses examined the connectivity of seven major cortical and sub-cortical brain networks (default mode network, executive control network (ECN), salience network, hippocampal network and three striatal...
March 15, 2023
Will Lawn, Xuejun Hao, Anna B. Konova et al.
preprint
Background: Despite the critical role of choice processes in substance use disorders, the neurobehavioral mechanisms guiding human decisions about drugs remain poorly understood. We adapted a neuroeconomic framework to characterize the neural encoding of subjective value (SV) for cannabis versus non-drug rewards (snacks) in near-daily cannabis users. We also assessed the impact of cannabis and...
Addiction
February 8, 2023
Will Lawn, Katie Trinci, Claire Mokrysz et al.
36 citations
Abstract Background and Aims Long‐term harms of cannabis may be exacerbated in adolescence, but little is known about the acute effects of cannabis in adolescents. We aimed to (i) compare the acute effects of cannabis in adolescent and adult cannabis users and (ii) determine if cannabidiol (CBD) acutely modulates the effects of delta‐9‐tetrahydocannabinol (THC). Design Randomised, double‐blind,...
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...
American Journal of Psychiatry
January 11, 2022
Meryem Grabski, Amy Mcandrew, Will Lawn et al.
169 citations
OBJECTIVE: Early evidence suggests that ketamine may be an effective treatment to sustain abstinence from alcohol. The authors investigated the safety and efficacy of ketamine compared with placebo in increasing abstinence in patients with alcohol use disorder. An additional aim was to pilot ketamine combined with mindfulness-based relapse prevention therapy compared with ketamine and alcohol...
Journal of Psychopharmacology
January 9, 2021
Abigail M. Freeman, Claire Mokrysz, Chandni Hindocha et al.
6 citations
BACKGROUND: While the acute effects of cannabis are relatively benign for most users, some individuals experience significant adverse effects. This study aimed to identify whether variation in schizotypal personality traits and frequency of cannabis use influence the acute effects of delta-9-tetrahydrocannabinol (THC). METHODS: Individual participant data from four double-blind, randomised,...
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...
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...
J Psychopharmacol
June 15, 2020
Anna Borissova, Bart Ferguson, Matthew B. Wall et al.
37 citations
BACKGROUND: 3,4-Methylenedioxymethamphetamine (MDMA) is being actively researched as an adjunct to psychotherapy. It may be beneficial to trust, empathy and cooperative behaviour due to its acute prosocial effects. AIM: To test (a) the acute effects of MDMA on measures of empathy, trust and cooperative behaviour, and (b) subacute changes in mood three days after MDMA administration. METHODS: =7...
Psychological Medicine
April 28, 2020
Claire Mokrysz, Natacha D. C. Shaban, Tom P. Freeman et al.
24 citations
BACKGROUND: Acute cannabis administration can produce transient psychotic-like effects in healthy individuals. However, the mechanisms through which this occurs and which factors predict vulnerability remain unclear. We investigate whether cannabis inhalation leads to psychotic-like symptoms and speech illusion; and whether cannabidiol (CBD) blunts such effects (study 1) and adolescence...
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...
Scientific Reports
February 28, 2018
Will Lawn, Jaime E. C. Hallak, José A. Crippa et al.
3 citations
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Scientific Reports
November 3, 2017
Will Lawn, Jaime E. C. Hallak, José Alexandre S. Crippa et al.
78 citations
Abstract Ayahuasca is a natural psychedelic brew, which contains dimethyltryptamine (DMT). Its potential as a psychiatric medicine has recently been demonstrated and its non-medical use around the world appears to be growing. We aimed to investigate well-being and problematic alcohol use in ayahuasca users, and ayahuasca’s subjective effects. An online, self-selecting, global survey examining...
Psychopharmacology
October 30, 2017
J. B. Stroud, Tom P. Freeman, Robert Leech et al.
102 citations
RATIONALE: Depressed patients robustly exhibit affective biases in emotional processing which are altered by SSRIs and predict clinical outcome. OBJECTIVES: The objective of this study is to investigate whether psilocybin, recently shown to rapidly improve mood in treatment-resistant depression (TRD), alters patients' emotional processing biases. METHODS: Seventeen patients with...
The International Journal of Neuropsychopharmacology
August 30, 2017
Tom P. Freeman, Rebecca Pope, Matthew B. Wall et al.
67 citations
Background: Despite the current shift towards permissive cannabis policies, few studies have investigated the pleasurable effects users seek. Here, we investigate the effects of cannabis on listening to music, a rewarding activity that frequently occurs in the context of recreational cannabis use. We additionally tested how these effects are influenced by cannabidiol, which may offset...
Psychopharmacology
September 2, 2016
Will Lawn, Tom P. Freeman, Rebecca Pope et al.
177 citations
RATIONALE: Anecdotally, both acute and chronic cannabis use have been associated with apathy, amotivation, and other reward processing deficits. To date, empirical support for these effects is limited, and no previous studies have assessed both acute effects of Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), as well as associations with cannabis dependence. OBJECTIVES: The objectives of...
Drug and Alcohol Review
March 1, 2016
Adam Winstock, Will Lawn, P. Deluca et al.
AbstractIntroduction and AimsTo assess the prevalence of use and subjective effect profile of methoxetamine among a group of polydrug users.Design and MethodsCross‐sectional, anonymous, online survey of UK‐based polydrug users was conducted. Prevalence of lifetime, last year and last month use, sourcing of the drugs, motivations for use, and subjective effect and risk profile compared with that...
Journal of Psychopharmacology
May 18, 2015
Sunjeev K. Kamboj, Emma J. Kilford, Stephanie Minchin et al.
43 citations
3,4-methylenedioxy- N-methylamphetamine (MDMA) produces diverse pro-social effects. Cognitive training methods rooted in Eastern contemplative practices also produce these effects through the development of a compassionate mindset. Given this similarity, we propose that one potential mechanism of action of MDMA in psychotherapy is through enhancing effects on intrapersonal attitudes (i.e....
October 7, 2014
Will Lawn, Rohan Borschmann, A. Cottrell et al.
Background: Methoxetamine is a novel psychoactive substance and a legal alternative to ketamine in many countries, including parts of the United States. Frequent recreational ketamine use can cause lower urinary tract symptoms, whereas methoxetamine was originally marketed as “bladder friendly”.Aims: (1) To determine changes in prevalence of methoxetamine use between 2011 and 2012 in the USA...
Journal of psychopharmacology (Oxford, England)
August 1, 2014
Will Lawn, Monica J Barratt, Martin L Williams et al.
The NBOMe compounds are a novel series of hallucinogenic drugs that are potent agonists of the 5-HT2A receptor, have a short history of human consumption and are available to buy online, in most countries. In this study, we sought to investigate the patterns of use, characteristics of users and self-reported effects. A cross-sectional anonymous online survey exploring the patterns of drug use...