Please use this link to access this publication. Abstract Rationale: Cannabis is mostly grown under illegal and unregulated circumstances, which seems to favour a product increasingly high in its main cannabinoid ∆-9-tetrahydrocannabinol (THC). ∆-9-tetrahydrocannabivarin (THCV) is a relatively untested cannabinoid which is said to be a cannabinoid receptor neutral antagonist, and may inhibit the effects of THC. Objectives: To explore the safety and tolerability of repeated THCV administration and its effects on symptoms normally induced by THC in a sample of healthy volunteers. Methods: Ten male cannabis users (<25 use occasions) were recruited for this within-subjects, placebo-controlled, double-blind, cross-over pilot study. 10mg oral pure...

Please use this link to access this publication. Abstract The effects of Δ9-tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, are a pressing concern for global mental health. Patterns of cannabis use are changing drastically owing to legalization, the availability of synthetic analogues (commonly termed spice), cannavaping and an emphasis on the purported therapeutic effects of cannabis. Many of the reinforcing effects of THC are mediated by the dopamine system. Owing to the complexity of the cannabinoid–dopamine interactions that take place, there is conflicting evidence from human and animal studies concerning the effects of THC on the dopamine system. Acute THC administration causes increased...

Please use this link to access this publication. Abstract Background and Objective Given that 29 U.S. states now have laws allowing medical marijuana use, this study examined mental and physical health correlates of medical versus nonmedical marijuana use among three age groups of adults (18–29, 30–49, and 50+). Methods Data came from the 2012–2013 National Epidemiologic Survey on Alcohol and Related Conditions (N = 36,309 respondents aged 18+). Logistic regression models were used to examine age group differences in associations of substance use and mental disorders and health conditions with medical versus nonmedical marijuana use. Results Of all respondents, 9.74% (N = 3,784) reported past-year marijuana use. Of...

Please use this link to access this publication. Abstract Plasmacytoid dendritic cells (pDCs) play a crucial role in host antiviral immune response through secretion of type I interferon. Interferon alpha (IFNα), a type I IFN, is critical for mounting the initial response to viral pathogens. A consequence of Human Immunodeficiency Virus-1 (HIV) infection is a decrease in both pDC number and function, but prolonged pDC activity has been linked with progression from HIV infection to the development of AIDS. Patients with HIV in the United States routinely use cannabinoid-based therapies to combat the side effects of HIV infection and antiretroviral therapy. However, cannabinoids, including...

Please use this link to access this publication. Abstract Δ9-Tetrahydrocannabinol (THC) is the psychoactive component of the plant Cannabis sativa and acts as a partial agonist at cannabinoid type 1 and type 2 receptors in the brain. The goal of this study was to assess the effect of THC on the cerebral glucose uptake in the rat brain. 21 male Sprague Dawley rats (12–13 w) were examined and received five different doses of THC ranging from 0.01 to 1 mg/kg. For data acquisition a Focus 120 small animal PET scanner was used and 24.1–28.0 MBq of [18F]-fluoro-2-deoxy-d-glucose were injected. The data were acquired for 70 min and arterial blood samples were collected throughout the scan. THC, THC-OH and THC-COOH...

Please use this link to access this publication. Abstract Background The current study examined the independent and interactive effects of HIV and marijuana (MJ) use on brain structure and cognitive function among a sample of HIV-positive (HIV + ) and HIV-negative (HIV–) individuals. Methods Participants (HIV+, n = 48; HIV–, n = 29) individuals underwent cognitive testing, questionnaires about substance use, and brain MRI. The HIV+ group was clinically stable based upon current plasma CD4 count, 50% had undetectable viral load (i.e., < 20 copies/mL), and all were on a stable regimen of cART. Results For HIV+ and HIV- participants, higher levels of MJ use were associated with smaller volumes in the entorhinal...

Abstract Use of Cannabis, the most widely used illicit drug worldwide, is associated with acute anxiety, and anxiety disorders following regular use. The precise neural and receptor basis of these effects have not been tested in man. Employing a combination of functional MRI (fMRI) and positron emission tomography (PET), we investigated whether the effects of delta-9-tetrahydrocannabinol (delta-9-THC), the main psychoactive ingredient of cannabis, on anxiety and on amygdala response while processing fearful stimuli were related to local availability of its main central molecular target, cannabinoid-1 (CB1) receptors in man. Fourteen healthy males were studied with fMRI twice, one month apart, following an oral dose...

Please use this link to access this publication. Abstract Background & Aims Delta-9-tetrahydrocannabinol (THC) is the most abundant cannabinoid from the plant Cannabis sativa. There is only equivocal evidence that THC has analgesic effects. We performed a phase 2 controlled trial to evaluate the analgesic efficacy, pharmacokinetics, safety, and tolerability of an oral tablet containing purified THC in patients with chronic abdominal pain. Methods Sixty-five patients with chronic abdominal pain for 3 months or more (numeric rating scale scores of 3 or more) after surgery or because of chronic pancreatitis were randomly assigned to groups given the THC tablet or identical matching placebos for 50–52 days. Subjects in the THC group were given the tablet first in a step-up phase (3 mg...

Please use this link to access this publication. Abstract Oral tetrahydrocannabinol (THC) is currently studied for its possible efficacy on dementia-related neuropsychiatric symptoms (NPS), but might lead to increased risk of falling. This was a randomised, double-blind, crossover study to evaluate the effects of THC on mobility in dementia patients. Eighteen community-dwelling patients (Mage=77 years) received 1.5 mg of oral THC twice daily and placebo, in random order, for three days, separated by a four-day washout. Balance and gait were assessed using SwayStarTM and GAITRiteTM within two hours after administration, in two consecutive intervention periods, under the following conditions: standing with eyes open (EO) and eyes...

Abstract Natural cannabinoids and their synthetic substitutes are the most widely used recreational drugs. Numerous clinical cases describe acute toxic symptoms and neurological consequences following inhalation of the mixture of synthetic cannabinoids known as “Spice.” Here we report that an intraperitoneal administration of the natural cannabinoid Δ9-tetrahydrocannabinol (10 mg/kg), one of the main constituent of marijuana, or the synthetic cannabinoid JWH-018 (2.5 mg/kg) triggered electrographic seizures in mice, recorded by electroencephalography and videography. Administration of JWH-018 (1.5, 2.5 and 5 mg/kg) increased seizure spikes dose-dependently. Pretreatment of mice with AM-251 (5 mg/kg), a cannabinoid receptor 1-selective antagonist, completely prevented cannabinoid-induced seizures. These data imply that abuse of cannabinoids...