Please use this link to access this publication. Abstract Cannabis is one of the most used drugs of abuse. It affects the brain reward system in animals, and has proven rewarding and addictive potential in humans. We used functional MRI to measure brain activity during reward anticipation in a monetary reward task. Long-term cannabis users were compared to healthy controls. An additional control group consisting of nicotine users was included. Cannabis users showed attenuated brain activity during reward anticipation in the nucleus accumbens compared to non-smoking controls, but not compared to smoking controls. Cannabis users showed decreased reward anticipation activity in the caudate nucleus, compared to both...

Abstract As previous work has highlighted the significance of the cannabinoid receptor 1 (CNR1) and fatty acid amide hydrolase (FAAH) genes with respect to cannabis dependence (CD), this study sought to characterize the neural mechanisms that underlie these genetic effects. To this end, we collected DNA samples and fMRI data using a cue-elicited craving paradigm in thirty-seven 3-day-abstinent regular marijuana users. The participants were grouped according to their genotype on two single-nucleotide polymorphisms (SNPs) earlier associated with CD phenotypes: rs2023239 in CNR1 and rs324420 in FAAH. Between-group comparisons showed that carriers of the CNR1 rs2023239 G allele had significantly greater activity in reward-related areas of the brain, such as the orbitofrontal cortex (OFC), inferior frontal...

Please use this link to access this publication. Abstract 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 structural magnetic resonance imaging studies to examine whether cannabis use is associated with significant changes in brain anatomy. We identified only 13 structural neuroimaging studies, which were diverse in terms of sample characteristics (e.g., age of participants, duration and frequency...

Abstract Objective Cannabis is associated with psychotic outcomes in numerous studies, an effect that is commonly attributed to Δ 9-tetrahydrocannabinol (Δ 9-THC). An increasing number of authors identify cannabidiol, another component of the cannabis plant, as an antipsychotic agent. The objective of the current study is to investigate the role of cannabidiol content in the association between cannabis use and psychiatric symptoms in a large non-clinical population of cannabis users. Methods In a web-based cross-sectional study we obtained detailed information about cannabis use and subclinical psychiatric experiences using the Community Assessment of Psychic Experiences (CAPE). Different types of cannabis (i.e. marijuana, hashish etc.) have distinctive...

Please use this link to access this publication. Abstract Background As access to cannabis has increased, there has been a rise in a condition called cannabinoid hyperemesis syndrome (CHS). This study estimates annual prevalence of suspected CHS at emergency department visits (ED) over an 11-year period in Northern California. Methods This retrospective observational cohort study used electronic health records from Kaiser Permanente Northern California. Two CHS case definitions were used to construct two cohorts of adults (18+) with ≥1 CHS visits from 2009 to 2019. The primary definition used a narrow definition based on past studies (CHS group 1) and an exploratory definition allowed...

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 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...

Key Points Question  Is receiving medical cannabis for a longer duration associated with reducing prescription opioid dosages among patients receiving long-term opioid therapy? Findings  In this cohort study among 8165 patients with chronic pain receiving long-term opioid therapy, receiving medical cannabis for a longer duration was associated with prescription opioid dosage reduction. Higher opioid dosages were associated with larger reductions. Meaning  These findings contribute evidence toward potential clinical benefits of medical cannabis in reducing prescription opioid intake, which may decrease patients’ risk of opioid overdose. Abstract Importance  Patients with chronic pain often receive long-term opioid therapy (LOT), which places them at risk of opioid use disorder and overdose....

Abstract Objectives: To assess the self-reported reasons for medical cannabis use within the southeastern United States and compare recreational and medical cannabis users. Methods: This study was a cross-sectional survey administered in 2017 through Amazon’s Mechanical Turk and enrolled 432 adult, regular cannabis users. Measures included demographics, cannabis use characteristics, and medical reasons for cannabis use. Results: Under half (47%) of respondents endorsed using cannabis for both medical and recreational reasons and 12% reported medical use only. The most commonly cited reasons for medical cannabis use were psychiatric and 60 unique medical conditions were listed. Recreational and medical users were similar on several measures...

Abstract Background: The use of cannabis by cancer patients has become increasingly common. With expanding access to medical cannabis, unsanctioned cannabis use is likely to increase. Despite this, the extent to which patients seeking specialized palliative or supportive care for cancer-related symptoms are actively using cannabis has not been well established. Objective: We sought to determine the extent to which patients seeking specialized symptom management were using cannabis and to compare the severity of cancer-related symptoms between users and nonusers. Methods: We conducted a retrospective review of objectively measured tetrahydrocannabinol (THC) and subjectively reported cannabis use, its demographic and clinical correlates, and patient-reported symptoms in 816 cancer...