Biological Psychiatry
December 1, 2008
Stefan Borgwardt, Paul Allen, Sagnik Bhattacharyya et al.
This study examined the effect of Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on brain activation during a motor inhibition task. Functional magnetic resonance imaging and behavioural measures were recorded while 15 healthy volunteers performed a Go/No-Go task following administration of either THC or CBD or placebo in a double-blind, pseudo-randomized, placebo-controlled repeated...
Fieldwork in Religion
November 27, 2008
Edward Macrae
11 citations
The article deals with the different effects of tolerant and prohibitionist policies associated with psychoactive substance use in Brazil. Whereas the licit use of ayahuasca has been successfully incorporated into mainstream Brazilian society, the ritual use of cannabis by one of the Santo Daime religious groups has never been fully accepted and remains a constant source of problems for the...
European Neuropsychopharmacology
November 2008
Maria Ellgren, A Artmann, O Tkalych et al.
Adolescence is a critical phase of active brain development often characterized by the initiation of marijuana (Cannabis sativa) use. Limited information is known regarding the endogenous cannabinoid system of the adolescent brain as well as related neurotransmitters that appear sensitive to cannabis exposure. We recently observed that adult rats pre-exposed to Delta-9-tetrahydrocannabinol...
Schizophrenia Bulletin
November 1, 2008
Cécile Henquet, Marta Di Forti, Paul D. Morrison et al.
Cannabis use is considered a contributory cause of schizophrenia and psychotic illness. However, only a small proportion of cannabis users develop psychosis. This can partly be explained by the amount and duration of the consumption of cannabis and by its strength but also by the age at which individuals are first exposed to cannabis. Genetic factors, in particular, are likely to play a role in...
The British Journal of Psychiatry
October 31, 2008
Stanley Zammit, Theresa HM Moore, Anne Lingford‐hughes et al.
275 citations
BACKGROUND: It is unclear if research findings support clinical opinion that cannabis use leads to worse outcomes in people with psychosis, or whether this impression is confounded by other factors. AIMS: To systematically review the evidence pertaining to whether cannabis affects outcome of psychotic disorders. METHOD: We searched 10 relevant databases (to November 2006), reference lists of...
Neuropsychopharmacology
October 2008
Tiziana Rubino, Daniela Vigano', Natalia Realini et al.
Few and often contradictory reports exist on the long-term neurobiological consequences of cannabinoid consumption in adolescents. The endocannabinoid system plays an important role during the different stages of brain development as cannabinoids influence the release and action of different neurotransmitters and promote neurogenesis. This study tested whether long-lasting interference by...
Schizophrenia Research
September 21, 2008
C. Corcoran, D. Kimhy, Arielle D. Stanford et al.
Background Cannabis use is reported to increase the risk for psychosis, but no prospective study has longitudinally examined drug use and symptoms concurrently in clinical high risk cases. Method We prospectively followed for up to 2 years 32 cases who met research criteria for prodromal psychosis to examine the relationship between substance use and clinical measures. Results Cases with a...
Acta Psychiatrica Scandinavica
September 19, 2008
Cécile Henquet, Araceli Rosa, Philippe Delespaul et al.
117 citations
OBJECTIVE: A functional polymorphism in the catechol-o-methyltransferase gene (COMT Val(158)Met) may moderate the psychosis-inducing effects of cannabis. In order to extend this finding to dynamic effects in the flow of daily life, a momentary assessment study of psychotic symptoms in response to cannabis use was conducted. METHOD: The experience sampling technique was used to collect data on...
Brain Research
September 4, 2008
Michael S Smirnov, Eugene A. Kiyatkin
Marijuana smoking dramatically alters responses to various environmental stimuli. To study this phenomenon, we assessed how delta-9-tetrahydrocannabinol (THC), a primary psychoactive ingredient of marijuana, affects locomotor and brain (nucleus accumbens or NAcc), muscle and skin temperature responses to natural arousing stimuli (one-minute tail-pinch and one-minute social interaction with...
American Journal on Addictions
September 3, 2008
Li-Tzy Wu, Christopher L. Ringwalt, Paolo Mannelli et al.
30 citations
We investigated the prevalence, patterns, and correlates of past‐year DSM‐IV hallucinogen use disorders (HUDs) among past‐year users of MDMA and other hallucinogens from a sample of Americans 18 or older (n = 37,227). Users were categorized as MDMA users and other hallucinogen users. Overall, one in five (20%) MDMA users and about one in six (16%) other hallucinogen users reported at least one...
Psychological Medicine
September 1, 2008
E. Barkus, S. Lewis
BackgroundThe relationship between cannabis use and psychosis is still a matter for debate. Accounting for the individual differences in subjective experiences to recreational cannabis use in the general population may hold some clues to the aetiological relationship between cannabis and psychotic symptoms. We hypothesized that schizotypy would account for the individual differences in...
Journal of Psychopharmacology
September 2008
Lineke Zuurman, Christine Roy, R C Schoemaker et al.
This randomised, double-blind, placebo-controlled, cross-over study was designed to identify which pharmacodynamic parameters most accurately quantify the effects of delta-9-Tetrahydrocannabinol (THC), the predominantly psychoactive component of cannabis. In addition, we investigated the acceptability and usefulness of a novel mode of intrapulmonary THC administration using a Volcano vaporizer...
Journal of Psychopharmacology
September 2008
A Strougo, Lineke Zuurman, Christine Roy et al.
Pharmacokinetics after pulmonary administration of delta-9-tetrahydrocannabinol (THC) and its major metabolites 11-OH-THC and 11-nor-9-COOH-THC was quantified. Additionally, the relationship between THC and its effects on heart rate, body sway and several visual analogue scales was investigated using pharmacokinetic-pharmacodynamic (PK-PD) modelling. This provided insights useful for the...
Neuropsychopharmacology
September 2008
Deepak Cyril D'Souza, Mohini Ranganathan, Gabriel Braley et al.
Cannabis is one of the most widely used illicit substances and there is growing interest in the association between cannabis use and psychosis. Delta-9-Tetrahydrocannabinol (Delta-9-THC) the principal active ingredient of cannabis has been shown to induce psychotomimetic and amnestic effects in healthy individuals. Whether people who frequently use cannabis are either protected from or are...
Journal of Neurochemistry
August 2008
Cristina Cadoni, Valentina Valentini, Gaetano Di Chiara
Although cannabinoid-induced behavioral sensitization and cross-sensitization with opiates has been recently demonstrated, no information is available on the associated state and responsiveness of dopamine (DA) transmission in the nucleus accumbens (NAc) shell and core. In this study we investigate by means of dual probe microdialysis, the effect of exposure to a sensitizing regimen of...
Schizophrenia Research
August 2008
Oliver J Mason, Celia J M Morgan, Ana Stefanovic et al.
This study reports a new measure of psychotomimetic states in the context of cannabis and ketamine use. The Psychotomimetic States Inventory (PSI) has sub-scales of Delusory Thinking, Perceptual Distortions, Cognitive Disorganization, Anhedonia, Mania and Paranoia. The PSI was administered in two independent group, repeated measures designs: an experimental study of ketamine and a naturalistic...
Psychopharmacology
August 2008
Jun-Xu Li, Lance R Mcmahon, Lisa R Gerak et al.
Opioid receptor agonists can enhance some effects of cannabinoid receptor agonists, and cannabinoid receptor agonists can enhance some effects of opioid receptor agonists; however, the generality of these interactions is not established. This study examined interactions between the discriminative stimulus and antinociceptive effects of mu opioid receptor agonists and...
Human Psychopharmacology: Clinical and Experimental
August 1, 2008
Nicholas T. van Dam, Mitch Earleywine, Greg DiGiacomo
AbstractObjectiveTo examine psychosis‐like symptoms in users of legal and illicit drugs.MethodsSchizotypal Personality Questionnaire (SPQ) scores were compared in groups of people with different exposure to cannabis, with the use of other drugs serving as a covariate. Supplemental analyses compared users of legal and illicit drugs with cannabis use as a covariate.ResultsWeekly (n = 111) and...
Annales pharmaceutiques francaises
August 2008
J Costentin
Today, the main route of introduction of tetrahydrocannabinol (THC), the main active substance of cannabis, into the human body is via the lungs, from smokes produced by combustion of a haschich-tobacco mixture. The use of a water pipe (nargileh-like) intensifies its fast supply to the body. THC reaches the brain easily where it stimulates CB1 receptors; their ubiquity underlies a wide variety...
Neuropharmacology
July 19, 2008
Jason R. Clapper, Regina A. Mangieri, Daniele Piomelli
The endocannabinoid system modulates neurotransmission at inhibitory and excitatory synapses in brain regions relevant to the regulation of pain, emotion, motivation, and cognition. This signaling system is engaged by the active component of cannabis, Δ9-tetrahydrocannabinol (Δ9-THC), which exerts its pharmacological effects by activation of G protein-coupled type-1 (CB1) and type-2 (CB2)...