Schizophrenia Research
October 30, 2010
Michael T Compton, Beth Broussard, Claire E. Ramsay et al.
Introduction Limited research indicates that pre-illness cannabis use may result in an earlier age at onset of psychosis, though little is known about the influence of prior cannabis use on the premorbid and prodromal phases. This study examined effects of prior or concurrent cannabis (as well as nicotine and alcohol) use on: (1) early adolescent (12–15 years) premorbid functioning, (2) late...
Psychopharmacology
October 30, 2010
Johannes G. Ramaekers, Eef L. Theunissen, Marjolein de Brouwer et al.
168 citations
INTRODUCTION: Previous research has shown that heavy cannabis users develop tolerance to the impairing effects of Δ9-tetrahydrocannabinol (THC) on neurocognitive functions. Animal studies suggest that chronic cannabis consumption may also produce cross-tolerance for the impairing effects of alcohol, but supportive data in humans is scarce. PURPOSE: The present study was designed to assess...
Neuropsychopharmacology
October 2010
Colm M P O'Tuathaigh, Magdalena Hryniewiecka, Aine Behan et al.
Cannabis use confers a two-fold increase in the risk for psychosis, with adolescent use conferring even greater risk. A high-low activity catechol-O-methyltransferase (COMT) polymorphism may modulate the effects of adolescent Δ-9-tetrahydrocannabinol (THC) exposure on the risk for adult psychosis. Mice with knockout of the COMT gene were treated chronically with THC (4.0 and 8.0 mg/kg over 20...
The British Journal of Psychiatry
October 2010
Celia J. A. Morgan, Gráinne Schäfer, Tom P. Freeman et al.
The two main constituents of cannabis, cannabidiol and Δ(9)-tetrahydrocannabinol (THC), have opposing effects both pharmacologically and behaviourally when administered in the laboratory. Street cannabis is known to contain varying levels of each cannabinoid. To study how the varying levels of cannabidiol and THC have an impact on the acute effects of the drug in naturalistic settings. Cannabis...
The British Journal of Psychiatry
September 30, 2010
Cécile Henquet, Rebecca Kuepper
16 citations
A recent study by Morgan and colleagues found that cannabidiol attenuates the acute cognitive effects of delta-9-tetrahydrocannabinol (THC). This is of interest as THC has been associated with the detrimental effects of cannabis on mental health in at-risk users, and the potency of cannabis is increasing across Europe.
Harm Reduction Journal
September 28, 2010
Anna Buadze, Rudolf Stohler, Beate Schulze et al.
There has been a considerable amount of debate among the research community whether cannabis use may cause schizophrenia and whether cannabis use of patients with schizophrenia is associated with earlier and more frequent relapses. Considering that studies exploring patients' view on controversial topics have contributed to our understanding of important clinical issues, it is surprising how...
Journal of Psychopharmacology
September 3, 2010
Gjh Dumont, J. G. Coen van Hasselt, M. de Kam et al.
38 citations
In Western societies a considerable percentage of young people expose themselves to the combination of 3,4-methylenedioxymethamphetamine (MDMA or ‘ecstasy’) and cannabis. The aim of the present study was to assess the acute effects of co-administration of MDMA and THC (the main psychoactive compound of cannabis) on pharmacokinetics, psychomotor performance, memory and subjective experience over...
Journal of Psychoactive Drugs
September 2010
Alecia Dager Schweinsburg, Brian C Schweinsburg, Krista Lisdahl Medina et al.
Some neurocognitive recovery occurs within a month of abstinence from heavy marijuana use, yet functional magnetic resonance imaging (fMRI) has revealed altered activation among recent and abstinent adult users. We compared fMRI response during a spatial working memory (SWM) task between adolescent marijuana users with brief and sustained durations of abstinence. Participants were 13 recent...
European Archives of Psychiatry and Clinical Neuroscience
September 2010
Patrik Roser, Beate Della, Christine Norra et al.
Mismatch negativity (MMN) is an auditory event-related potential indicating auditory sensory memory and information processing. The present study tested the hypothesis that chronic cannabis use is associated with deficient MMN generation. MMN was investigated in age- and gender-matched chronic cannabis users (n = 30) and nonuser controls (n = 30). The cannabis users were divided into two groups...
Substance Use & Misuse
September 2010
Valentina Lorenzetti, Dan I Lubman, Sarah Whittle et al.
In animal studies, tetrahydrocannabinol (THC) has been found to affect brain morphology, particularly within areas rich in cannabinoid receptors (e.g., hippocampus, cerebral cortex). While cannabis remains the most widely used illicit drug worldwide, there has been limited work investigating its effects on human brain tissue. In this paper, we conducted a systematic review of existing...