Drug Testing and Analysis
April 2018
David Potter, Kathy Hammond, Shaun Tuffnell et al.
In 2005 and 2008, studies reported that cannabis in England had become dominated by the sinsemilla (unseeded female) form. The average potency (Δ9 -tetrahydrocannabinol [THC] content) of this material had doubled over the previous decade. Cannabis resin then circulating contained approximately equal ratios of THC and cannabidiol (CBD), whereas sinsemilla was almost devoid of CBD. Despite raised...
Experimental and Clinical Psychopharmacology
April 2018
Briana J. Hempel, Matthew M Clasen, Katharine H Nelson et al.
Rising interest in medical marijuana has prompted research into its phytocannabinoid constituents, particularly Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). Coadministration of CBD with THC has been shown to modulate a number of THC's effects, including its negative stimulus properties (e.g., anxiety, paranoia, psychosis) in a clinical setting. The present series of experiments extended...
Schizophrenia Research
April 1, 2018
Susan Whitfield-Gabrieli, Adina S. Fischer, Angela Henricks et al.
Nearly half of patients with schizophrenia (SCZ) have co-occurring cannabis use disorder (CUD), which has been associated with decreased treatment efficacy, increased risk of psychotic relapse, and poor global functioning. While reports on the effects of cannabis on cognitive performance in patients with SCZ have been mixed, study of brain networks related to executive function may clarify the...
Cannabis and Cannabinoid Research
March 29, 2018
Nina Levar, Alan N. Francis, Matthew J. Smith et al.
33 citations
Introduction: Memory impairment is one of the most commonly reported effects of cannabis use, especially among those who initiate use earlier, perhaps due to the effects of delta-9- tetrahydrocannabinol on cannabinoid (CB1) receptors in the brain. Studies have increasingly investigated whether cannabis use is associated with impairments in verbal memory, and with alterations in brain structures...
Psychiatry Research Neuroimaging
March 28, 2018
H. Abush, S. Ghose, Erin van Enkevort et al.
Associations between cannabis use and psychotic disorders suggest that cannabis may be a contributory risk factor in the neurobiology of psychosis. In this study, we examined brain structure characteristics, total and regional gray matter density (GMD), using Voxel Based Morphometry, in psychotic individuals, stratified by history of cannabis use (total n=109). We also contrasted GMD estimates...
Frontiers in Psychiatry
March 27, 2018
Ruth Braidwood, Samantha Mansell, Jon Waldron et al.
7 citations
Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM) for future events. The present study examined prospective memory in daily cannabis users who were either dependent (n = 18) or non-dependent (n = 18), and compared them with non-using controls (n = 18). The effect of future event...
Brain Sciences
March 13, 2018
Andrew C. Parrott
13 citations
Many novel psychoactive substances (NPS) have entered the recreational drug scene in recent years, yet the problems they cause are similar to those found with established drugs. This article will debate the psychobiological effects of these newer and more traditional substances. It will show how they disrupt the same core psychobiological functions, so damaging well-being in similar ways. Every...
Psychological Medicine
March 5, 2018
Sagnik Bhattacharyya, Thomas T. J. Sainsbury, Paul Allen et al.
16 citations
BACKGROUND: Cannabis and its main psychoactive ingredient δ-9-tetrahydrocannibidiol (THC) can induce transient psychotic symptoms in healthy individuals and exacerbate them in those with established psychosis. However, not everyone experience these effects, suggesting that certain individuals are particularly susceptible. The neural basis of this sensitivity to the psychotomimetic effects of...
Planta Medica
March 2018
Elsayed A Ibrahim, Waseem Gul, Shahbaz W Gul et al.
Cannabis (Cannabis sativa L.) is an annual herbaceous plant that belongs to the family Cannabaceae. Trans-Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) are the two major phytocannabinoids accounting for over 40% of the cannabis plant extracts, depending on the variety. At the University of Mississippi, different strains of C. sativa, with different concentration ratios of CBD and...
Journal of Psychiatry and Neuroscience
March 2018
Pamela Prini, Franceso Rusconi, Erica Zamberletti et al.
Increasing cannabis consumption among adolescents, studies that link its early use with mental illnesses, and the political debate on cannabis legalization together call for an urgent need to study molecular underpinnings of adolescent brain vulnerability. The emerging role of epigenetic mechanisms in psychiatric diseases led us to hypothesize that epigenetic alterations could play a role in...
Journal of Psychopharmacology
March 2018
Regi Schipper, Mathilde Dekker, Lieuwe de Haan et al.
Cannabis use disorders are frequently comorbid in patients with a psychotic disorder and are associated with worse outcomes. To date there are no proven effective strategies to achieve cannabis abstinence in this population. An alternative for abstinence might be harm reduction, i.e. replacing the use of street cannabis with high tetrahydrocannabinol and low cannabidiol levels by medicinal...
Journal of Neuroimmune Pharmacology
March 2018
Jun Panee, Mariana Gerschenson, Linda Chang
Marijuana (MJ) use is associated with cognitive deficits. Both mitochondrial (mt) dysfunction and gut dysbiosis also affect cognition. We examined whether cognition is related to peripheral blood mononuclear cells' (PBMCs) mt function and fecal microbiota in chronic MJ users. Nineteen chronic MJ users and 20 non-users were evaluated using the Cognition Battery in NIH Toolbox, their mt function...
Neuropsychopharmacology
March 2018
Francesca Filbey, Sina Aslan, Hanzhang Lu et al.
Given the known vascular effects of cannabis, this study examined the neurophysiological factors that may affect studies of brain activity in cannabis users. We conducted a systematic evaluation in 72 h abstinent, chronic cannabis users (N=74) and nonusing controls (N=101) to determine the association between prolonged cannabis use and the following neurophysiological indicators: (1) global and...
Psychopharmacology
March 2018
Kaeli Zimmermann, Shuxia Yao, Marcel Heinz et al.
Intact cognitive and emotional functioning is vital for the long-term success of addiction treatment strategies. Accumulating evidence suggests an association between chronic marijuana use and lasting alterations in cognitive brain function. Despite initial evidence for altered emotion processing in dependent marijuana users after short abstinence periods, adaptations in the domain of emotion...
Journal of Psychopharmacology
March 2018
Julio A Yanes, Michael C Riedel, Kimberly L Ray et al.
Lagging behind rapid changes to state laws, societal views, and medical practice is the scientific investigation of cannabis's impact on the human brain. While several brain imaging studies have contributed important insight into neurobiological alterations linked with cannabis use, our understanding remains limited. Here, we sought to delineate those brain regions that consistently demonstrate...
Journal of Studies on Alcohol and Drugs
March 2018
Hayley Treloar Padovano, Robert Miranda
The present study used youth's in vivo reports of subjective responses to cannabis while smoking in their natural environments to identify real-world mechanisms of topiramate treatment for cannabis misuse. Participants were 40 cannabis users (≥ twice weekly in past 30 days), ages 15-24 years (47.5% female), with at least one cannabis use episode during the final 3 weeks of a 6-week, randomized...
Psychopharmacology
March 2018
Michael B. Gatch, Michael J Forster
Novel synthetic cannabinoid compounds continue to appear in the market advertised as legal alternatives to marijuana and the older synthetic cannabinoid compounds which are now controlled substances. Most of these newer compounds have been found to act at CB1 receptors, so the purpose of this study was to study the abuse liability of these compounds. Five of these compounds (BB-22, FUB-PB-22,...
Synapse
March 2018
Bryan Kolb, Yilin Li, Terry Robinson et al.
Psychoactive drugs have the ability to alter the morphology of neuronal dendrites and spines and to influence later experience-dependent structural plasticity. If rats are given repeated injections of psychomotor stimulants (amphetamine, cocaine, nicotine) prior to being placed in complex environments, the drug experience interferes with the ability of the environment to increase dendritic...
Cannabis and Cannabinoid Research
March 1, 2018
Nadia Solowij, Samantha J Broyd, Camilla Beale et al.
Introduction: Chronic cannabis use has been associated with impaired cognition and elevated psychological symptoms, particularly psychotic-like experiences. While Δ9-tetrahydrocannabinol (THC) is thought to be primarily responsible for these deleterious effects, cannabidiol (CBD) is purported to have antipsychotic properties and to ameliorate cognitive, symptomatic, and brain harms in cannabis...
Brain Sciences
February 27, 2018
Koby Cohen, Aviv Weinstein
Background—Cannabis is the most popular illicit drug in the Western world. Repeated cannabis use has been associated with short and long-term range of adverse effects. Recently, new types of designer-drugs containing synthetic cannabinoids have been widespread. These synthetic cannabinoid drugs are associated with undesired adverse effects similar to those seen with cannabis use, yet, in more...