Neuropharmacology
June 2015
D Matthew Walentiny, Robert E Vann, Jenny L Wiley
A number of studies have examined the ability of the endogenous cannabinoid anandamide to elicit Δ(9)-tetrahydrocannabinol (THC)-like subjective effects, as modeled through the THC discrimination paradigm. In the present study, we compared transgenic mice lacking fatty acid amide hydrolase (FAAH), the enzyme primarily responsible for anandamide catabolism, to wildtype counterparts in a THC...
Western Journal of Emergency Medicine
May 7, 2015
Quan M. Bui, Scott Simpson, Kimberly Nordstrom
We use a case report to describe the acute psychiatric and medical management of marijuana intoxication in the emergency setting. A 34-year-old woman presented with erratic, disruptive behavior and psychotic symptoms after recreational ingestion of edible cannabis. She was also found to have mild hypokalemia and QT interval prolongation. Psychiatric management of cannabis psychosis involves...
Schizophrenia Research
May 1, 2015
Toby 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...
Psychiatry Research
April 30, 2015
Katherine A Epstein, Sanjiv Kumra
Recurrent exposure to cannabis in adolescence increases the risk for later development of psychosis, but there are sparse data regarding the impact of cannabis use on brain structure during adolescence. This pilot study investigated the effect of cannabis use disorder (CUD) upon white matter fractional anisotropy (WM FA) values in non-psychotic treatment-seeking adolescents relative to...
Psychiatry Research
April 15, 2015
Sania Shakoor, Helena M. S. Zavos, Philip Mcguire et al.
37 citations
Cannabis users are more likely to have psychotic experiences (PEs). The degree to which these associations are driven by genetic or environmental influences in adolescence is unknown. This study estimated the genetic and environmental contributions to the relationship between cannabis use and PEs. Specific PEs were measured in a community-based twin sample (4830 16-year-old pairs) using...
NeuroImage: Clinical
April 9, 2015
Kristoffer Romero, Bennis Pavisian, W. Staines et al.
Objective A subset of patients with multiple sclerosis (MS) smoke cannabis to relieve symptoms including spasticity and pain. Recent evidence suggests that smoking cannabis further impairs cognition in people with MS and is linked to impaired functional brain changes. No such association, however, has been reported between cannabis use and structural brain changes, hence the focus of the...
Drug and Alcohol Dependence
April 1, 2015
Leslie H. Lundahl, Mark K Greenwald
The current study tested whether oral Δ(9)-tetrahydrocannabinol (THC: 0-, 10-, and 20-mg) pretreatment would attenuate polysensory cue-induced craving for marijuana. Cannabis dependent participants (7 males and 7 females, who smoked on average 5.4 ± 1.1 blunts daily) completed 3 experimental sessions (oral THC pretreatment dose; counterbalanced order) using a placebo-controlled within-subject...
Molecular Psychiatry
March 31, 2015
Jordi Riba, Marta Valle, Frederic Sampedro et al.
41 citations
Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control....
Psychopharmacology
March 11, 2015
Amir I. A. Ahmed, G. A. H. van den Elsen, A. Colbers et al.
Data on safety, pharmacodynamics, and pharmacokinetics of tetrahydrocannabinol (THC) are lacking in dementia patients. In this randomized, double-blind, placebo-controlled, crossover trial, we evaluated the safety, pharmacodynamics, and pharmacokinetics of THC in ten patients with dementia (mean age 77.3 ± 5.6). For 12 weeks, participants randomly received oral THC (weeks 1–6, 0.75 mg; weeks...
PLoS One
March 4, 2015
E. Tyler, S. Jones, Nancy B. Black et al.
Objectives Although cannabis use is common in bipolar disorder and may contribute to worse clinical outcomes, little is understood about the relationship between this drug and bipolar disorder over the course of daily life. The aim of study was to examine the effect of cannabis on affect and bipolar symptoms in a group of individuals with bipolar disorder. Methods Twenty-four participants with...
Journal of Analytical Toxicology
March 4, 2015
Nathalie A. Desrosiers, Johannes G. Ramaekers, Émeline Chauchard et al.
136 citations
Δ9-Tetrahydrocannabinol (THC), the primary psychoactive constituent in cannabis, impairs psychomotor performance, cognition and driving ability; thus, driving under the influence of cannabis is a public safety concern. We documented cannabis' psychomotor, neurocognitive, subjective and physiological effects in occasional and frequent smokers to investigate potential differences between these...
Schizophrenia Bulletin
March 2015
Daniel Freeman, Graham Dunn, Robin Murray et al.
Paranoia is receiving increasing attention in its own right, since it is a central experience of psychotic disorders and a marker of the health of a society. Paranoia is associated with use of the most commonly taken illicit drug, cannabis. The objective was to determine whether the principal psychoactive ingredient of cannabis-∆(9)-tetrahydrocannabinol (THC)-causes paranoia and to use the drug...
European Neuropsychopharmacology
March 2015
Chandni Hindocha, Tom P. Freeman, Gráinne Schäfer et al.
Acute administration of the primary psychoactive constituent of cannabis, Δ-9-tetrahydrocannabinol (THC), impairs human facial affect recognition, implicating the endocannabinoid system in emotional processing. Another main constituent of cannabis, cannabidiol (CBD), has seemingly opposite functional effects on the brain. This study aimed to determine the effects of THC and CBD, both alone and...
Schizophrenia Research
March 2015
Katherine A Epstein, Sanjiv Kumra
During late adolescence, progressive cortical thinning occurs in heteromodal association cortex (HASC) that is thought to subserve cognitive development. However, the impact of cannabis use disorder (CUD) upon cortical gray matter development in both healthy adolescents and adolescents with early-onset schizophrenia (EOS) is unclear. T1-weighted magnetic resonance images were acquired from 79...
Psychological Medicine
February 5, 2015
F J van der Meer, Eva Velthorst, Genetic Risk And Outcome Of Psychosis (group) Investigators
49 citations
BACKGROUND: Prospective studies on the relationship between course of cannabis use and clinical outcome in patients with non-affective psychotic disorders are inconclusive. The current study examined whether (1) persistent, recently started, discontinued and non-cannabis-using patients with a psychotic disorder differed with regard to illness outcome at 3-year follow-up, and (2) whether timing...
Therapeutic Advances in Psychopharmacology
February 1, 2015
Hannah Steeds, Robin Carhart-Harris, James Stone
132 citations
Schizophrenia is a complex mental health disorder with positive, negative and cognitive symptom domains. Approximately one third of patients are resistant to currently available medication. New therapeutic targets and a better understanding of the basic biological processes that drive pathogenesis are needed in order to develop therapies that will improve quality of life for these patients....
Acta Psychiatrica Scandinavica
January 9, 2015
Andrea M. Auther, Kristin Cadenhead, Ricardo E Carrión et al.
46 citations
OBJECTIVE: Cannabis use has been examined as a predictor of psychosis in clinical high-risk (CHR) samples, but little is known about the impact of other substances on this relationship. METHOD: Substance use was assessed in a large sample of CHR participants (N = 370, mean age = 18.3) enrolled in the multisite North American Prodrome Longitudinal Study Phase 1 project. Three hundred and...
Journal of Psychopharmacology
January 8, 2015
JHP van Wel, DB Spronk, Kim P. C. Kuypers et al.
23 citations
Trait impulsivity has been linked to addiction in humans. It has been suggested that drug users with high trait impulsivity levels are more sensitive to subjective drug intoxication. This study assessed whether subjective response to drugs differs between drug users with normal or high levels of trait impulsivity. Regular drug users (N = 122) received doses of cocaine HCl, cannabis, and placebo...
European Neuropsychopharmacology
January 2015
Sagnik Bhattacharyya, Zerrin Atakan, Rocío Martín‐Santos et al.
Cannabis use can induce acute psychotic symptoms and increase the risk of schizophrenia. Impairments in inhibitory control and processing are known to occur both under the influence of cannabis and in schizophrenia. Whether cannabis-induced impairment in inhibitory processing is related to the acute induction of psychotic symptoms under its influence is unclear. We investigated the effects of...
Neurobiology of Disease
2015
Tiziana Rubino, Pamela Prini, Fabiana Piscitelli et al.
Current concepts suggest that exposure to THC during adolescence may act as a risk factor for the development of psychiatric disorders later in life. However, the molecular underpinnings of this vulnerability are still poorly understood. To analyze this, we investigated whether and how THC exposure in female rats interferes with different maturational events occurring in the prefrontal cortex...