Neuroscience and Biobehavioral Reviews
June 3, 2026
Isabella Goodwin, Dominic Oliver, Edward Chesney et al.
Global shifts towards the liberalisation of cannabis policies have increased the potency of cannabis products, alongside their accessibility, diversity, and the number of inexperienced cannabis consumers. There is a lack of systematic evidence on the subjective effects of cannabis' main psychoactive compound, Δ9-tetrahydrocannabinol (THC). We systematically reviewed and meta-analysed data from...
British Journal of Psychiatry
December 3, 2024
Edward Chesney, Thomas J. Reilly, Fraser Scott et al.
Background Abrupt cessation of heavy cannabis use can cause a withdrawal syndrome characterised by irritability, anxiety, insomnia, reduced appetite and restlessness. Recent reports have also described people in whom cannabis withdrawal immediately preceded the acute onset of psychosis. Aims To identify cases of psychosis associated with cannabis withdrawal. Method We completed a systematic...
Psychiatry and Clinical Neurosciences
April 18, 2023
Lucy Chester, L. Valmaggia, M. Kempton et al.
Evidence for case–control studies suggests that cannabis use is a risk factor for the development of psychosis. However, there have been limited prospective studies and the direction of this association remains controversial. The primary aim of the present study was to examine the association between cannabis use and the incidence of psychotic disorders in people at clinical high risk of...
Cannabis and Cannabinoid Research
December 9, 2022
Lucy Chester, Amir Englund, Edward Chesney et al.
20 citations
Background: The effects of cannabis are thought to be mediated by interactions between its constituents and the endocannabinoid system. Delta-9-tetrahydrocannabinol (THC) binds to central cannabinoid receptors, while cannabidiol (CBD) may influence endocannabinoid function without directly acting on cannabinoid receptors. We examined the effects of THC coadministered with different doses of CBD...
Schizophrenia Research
May 1, 2015
T. Winton-Brown, V. Kumari, F. Windler et al.
Sensorimotor gating, measured as the modification of eye blink startle reflexes to loud acoustic stimuli by quieter preceding stimuli, is altered in those with psychosis, their relatives and those at high clinical risk for psychosis. Alterations have also been shown in cannabis users, albeit to a lesser extent, and cannabis is a known risk factor for the onset of psychosis in clinically and...
Psychological Medicine
October 1, 2012
Zerrin Atakan, Sagnik Bhattacharyya, Paul Allen et al.
54 citations
BACKGROUND: Cannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms. Method In a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were...
Current Pharmaceutical Design
September 12, 2012
Rocío Martín‐Santos, José Alexandre S. Crippa, Albert Batalla et al.
288 citations
RATIONALE: Animal and humans studies suggest that the two main constituents of cannabis sativa, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have quite different acute effects. However, to date the two compounds have largely been studied separately. OBJECTIVE: To evaluate and compare the acute pharmacological effects of both THC and CBD in the same human volunteers. METHODS: A...
Schizophr Bull
January 26, 2012
Oliver Howes, Paul Shotbolt, Michael Bloomfield et al.
94 citations
Dopaminergic function in the psychosis spectrum: an [18F]-DOPA imaging study in healthy individuals with auditory hallucinations.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
June 2011
Toby T Winton-Brown, Paul Allen, Sagnik Bhattacharyya et al.
Although the effects of cannabis on perception are well documented, little is known about their neural basis or how these may contribute to the formation of psychotic symptoms. We used functional magnetic resonance imaging (fMRI) to assess the effects of Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) during visual and auditory processing in healthy volunteers. In total, 14 healthy...
Pharmacopsychiatry
July 22, 2010
James Stone, Paul D. Morrison, Judith Nottage et al.
13 citations
We tested the hypothesis that THC disrupts self-timed actions in healthy volunteers, and that this effect is related to self-rated perceptions of time distortion. We found that THC impaired subjective time perception and reduced the rate of button pressing, although the change in the rate of button pressing was more closely related to impaired concentration and intoxication. We conclude that...
The International Journal of Neuropsychopharmacology
September 24, 2009
Paolo Fusar‐poli, Paul Allen, Sagnik Bhattacharyya et al.
165 citations
Cannabis sativa, the most widely used illicit drug, has profound effects on levels of anxiety in animals and humans. Although recent studies have helped provide a better understanding of the neurofunctional correlates of these effects, indicating the involvement of the amygdala and cingulate cortex, their reciprocal influence is still mostly unknown. In this study dynamic causal modelling (DCM)...
Psychological Medicine
July 23, 2009
Rocío Martín‐Santos, Ana B. Fagundo, José Alexandre S. Crippa et al.
207 citations
BACKGROUND: We conducted a systematic review to assess the evidence for specific effects of cannabis on brain structure and function. The review focuses on the cognitive changes associated with acute and chronic use of the drug. METHOD: We reviewed literature reporting neuroimaging studies of chronic or acute cannabis use published up until January 2009. The search was conducted using Medline,...
Archives of General Psychiatry
April 1, 2009
Sagnik Bhattacharyya, Paolo Fusar‐poli, Stefan Borgwardt et al.
250 citations
CONTEXT: Cannabis sativa use can impair verbal learning, provoke acute psychosis, and increase the risk of schizophrenia. It is unclear where C. sativa acts in the human brain to modulate verbal learning and to induce psychotic symptoms. OBJECTIVES: To investigate the effects of 2 main psychoactive constituents of C. sativa, Delta9-tetrahydrocannabinol (Delta9-THC) and cannabidiol, on regional...
Archives of General Psychiatry
2009
Paolo Fusar‐poli, José A. Crippa, Sagnik Bhattacharyya et al.
461 citations
CONTEXT: Cannabis use can both increase and reduce anxiety in humans. The neurophysiological substrates of these effects are unknown. OBJECTIVE: To investigate the effects of 2 main psychoactive constituents of Cannabis sativa (Delta9-tetrahydrocannabinol [Delta9-THC] and cannabidiol [CBD]) on regional brain function during emotional processing. DESIGN: Subjects were studied on 3 separate...
The British Journal of Psychiatry
September 1, 1994
Philip Mcguire, Helen Cope, Thomas Fahy
187 citations
Background 3,4-methylenedioxymethamphetamine (MDMA or ‘Ecstasy’) has become one of the most widely used illicit substances in the UK. Little is known of the psychiatric morbidity which may be associated with its use. We have examined this association by collecting a series of psychiatric cases in which MDMA use was a prominent feature. Method Patients presenting between 1990 and 1992 with...
Schizophrenia Research
September 1, 1994
Philip Mcguire, P Jones, I Harvey et al.
The Present State Examination was used to assess the psychopathology of 23 psychotic patients who were cannabis positive on urinary screening, and 46 matched drug-free controls. Cases and controls were indistinguishable in terms of psychopathology, DSMIII diagnoses, onset of recent illness, the proportion of first admissions, ethnicity, and socio-economic class, differing only in their...
BMJ
March 23, 1991
Philip Mcguire, Thomas Fahy
128 citations
Methylenedioxymetamphetamine (MDMA, "ecstasy") is a hallucinogenic amphetamine that combines the effects of amphetamines and lysergic acid diethylamide (LSD) and has become increasingly popular in the United Kingdom.We report two cases of chronic paranoid psychoses after heavy misuse of this drug. Case reports CASE I