High-potency marijuana impairs executive function and inhibitory motor control

Relation of Cannabis Use Frequency and Gambling Behavior in Individuals Who Gamble Under the Influence of Cannabis

There appears to be a significant positive relation between problematic cannabis use and problem gambling behaviors. Recent reviews have noted that individuals who use cannabis more frequently may experience less acute executive functioning impairment than those who use cannabis less often. The current study explored the relation between cannabis use frequency and problem gambling outcomes in those who gamble under the influence of cannabis, to explore if increased cannabis use frequency increases reported gambling problems, or is the reported effect on their gambling behavior is lessened in individuals who consume cannabis regularly? 769 individuals who gambled at least weekly were recruited from a crowdsource platform. These individuals reported their gambling behavior and cannabis use. To explore the relation between cannabis use frequency and problem gambling severity, regression models following both a simple linear model and a quadratic model were generated and evaluated for model fit and significance. The quadratic model was found to best fit the relation between cannabis use frequency and problem gambling severity. The quadratic model was also found to best fit the relation between frequency of time spent gambling under the influence of cannabis and problem gambling severity. Those who consumed cannabis infrequently or very frequently reported fewer gambling problems overall compared to those who consumed cannabis at a moderate frequency. The acute relation between cannabis use and gambling may be more complex than simply amplifying problematic gambling behaviors.

Metabolomic profiling of cannabis use and cannabis intoxication in humans

Acute intoxication from Δ9-tetrahydrocannabinol (THC, the primary active ingredient of cannabis) can lead to neurocognitive impairment and interference with day-to-day operations, such as driving. Present evaluations of THC-induced impairment in legal settings rely on biological drug tests that solely establish cannabis use, rather than cannabis impairment. The current study evaluated the metabolome in blood collected from occasional and chronic cannabis users (N = 35) at baseline and following treatments with cannabis (300 μg/kg THC) and placebo, with the aim to identify unique metabolic alterations that are associated with acute cannabis intoxication and cannabis use frequency. Blood samples were collected at baseline and repeatedly during 70 min after treatment. Sustained attention performance and ratings of subjective high were taken twice within 40 min after treatment. Metabolomic fingerprints of occasional and chronic cannabis users were distinctly different at baseline, when both groups were not intoxicated. A total of 14 metabolites, mainly related to endocannabinoid and amino acid metabolism, were identified that distinguished chronic from occasional cannabis users and that yielded a discriminant analysis model with an 80% classification rate (95% CI: 61-91%). Distinct metabolomic fingerprints were found for occasional cannabis users who, in contrast to chronic cannabis users, showed attentional impairment and elevated ratings of subjective high during cannabis intoxication. These included increments in organic acids, β-hydroxybutyrate and second messenger ceramides. The current study demonstrates the feasibility of the metabolomics approach to identify metabolic changes that are specific to the neurocognitive state of cannabis intoxication and to the history of cannabis use.

High-Potency Cannabis Use and Health: A Systematic Review of Observational and Experimental Studies

OBJECTIVE

Amid continuously rising concentrations of delta-9-tetrahydrocannabinol (THC) in cannabis (i.e., potency), high-potency cannabis is a major topic in contemporary cannabis policy discussions, yet its impact on health is not well understood. The authors conducted a systematic review of observational and experimental studies examining the relationship between high-potency cannabis use and a range of health outcomes.

METHODS

Records were obtained from a systematic search of five biomedical research databases. The authors developed ecologically relevant potency (percent THC) exposure-comparison categories (1%-9%, 10%-19%, 20%-30%, kief/resin [∼30%-50%], concentrates [≥60%]) and used a landmark scientific report on cannabis and cannabinoids to determine outcome eligibility. Two reviewers independently conducted article screening and selection, extraction, and quality assessment. Findings were synthesized using both quantitative (association direction, binomial test) and narrative approaches. Certainty in the evidence was determined via the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework.

RESULTS

Of 4,545 screened records, 42 were eligible. Most studies addressed outcomes in the mental health, "problem" cannabis use, and other substance use domains. Findings in the "problem" cannabis use domain were suggestive of an association with higher-potency cannabis use. Findings were less consistent in other domains but tended to favor poorer outcomes with higher-potency use. Therapeutic outcomes were limited and mixed. Overall, certainty in the evidence was "very low."

CONCLUSIONS

Findings within the "problem" cannabis use domain were suggestive of an association with high-potency use. Research is largely limited to cross-sectional studies spanning few adverse health domains, underscoring the need for prospective studies probing therapeutic, cardiorespiratory, cancer, and pre- and perinatal outcomes. Policies to curb high-potency cannabis use may be warranted while the evidence base improves.

Dose of Product or Product Concentration: A Comparison of Change in Heart Rate by THC Concentration for Participants Using Cannabis Daily and Occasionally

Introduction: Studies show that acute cannabis use significantly increases heart rate (HR) and mildly raises blood pressure in the minutes following smoked or inhaled use of cannabis. However, less is known about how the THC concentration of the product or an individual's frequency of use (i.e., tolerance) may affect the magnitude of the change in HR. It is also relatively unexamined how the physical effects of increased HR after acute cannabis use relate to self-reported drug effects or blood THC levels. Aims: To describe the relationship between THC concentration of product used, self-reported subjective intoxication, THC blood levels, and frequency of cannabis use with the change in HR after acute cannabis use. Materials and Methods: Participants (n = 140) were given 15 min to smoke self-supplied cannabis ad libitum, HR was measured at baseline and an average of 2 min post-cannabis smoking. The ARCI-Marijuana scale and Visual Analog Scales (VAS) were administered, and blood samples were taken at both time points. Participants were asked about their frequency of use. Information about the product used was recorded from the package. Linear regression was used to analyze the relationship between changes in HR (post-pre cannabis use) and post-cannabis use HR, blood THC concentration, THC product concentration, frequency of use, and self-reported drug effect. Results: There was a significantly higher HR among those who smoked cannabis compared to the controls (p < 0.001), which did not significantly differ by frequency of use (p = 0.18). Higher concentration THC (extract) products did not produce a significantly different HR than lower concentration (flower) products (p = 0.096). VAS score was associated with an increase in HR (p < 0.05). Overall, blood THC levels were not significantly related to the change in HR (p = 0.69); however, when probed, there was a slight positive association among the occasional use group only. Discussion: Cardiovascular effects of cannabis consumption may not be as subject to tolerance with daily cannabis use and do not directly increase with THC concentration of the product. This is a departure from other effects (i.e., cognitive, subjective drug effects) where tolerance is well established. These findings also suggest that, at least among those with daily use, higher concentration THC products (>60%) do not necessarily produce cardiovascular physiological effects that are significantly more robust than lower concentration (<20%) products.

Attention Deficit Hyperactivity Disorder, Cannabis Use, and the Endocannabinoid System: A Scoping Review

There is emerging evidence that the endocannabinoid system (ECS) plays a significant role in the pathophysiology of many psychiatric disorders, including attention deficit hyperactivity disorder (ADHD). Increasing evidence suggests that a number of neurobiological correlates between endogenous cannabinoid function and cognitive dysfunction are seen in ADHD, making the ECS a possible target for therapeutic interventions. Cannabis use and cannabis use disorder are more prevalent in individuals with ADHD, compared to the general population, and there is growing popular perception that cannabis is therapeutic for ADHD. However, the relationship between cannabis use and ADHD symptomology is poorly understood. Further understanding of the role of the ECS in ADHD pathophysiology and the molecular alterations that may be a target for treatment is needed. To further the science on this emerging area of research, this scoping review describes the preclinical and clinical evidence seeking to understand the relationship between the ECS and ADHD.

The effects of standardized cannabis products in healthy volunteers and patients: a systematic literature review

Introduction

There is growing recognition of the potential of cannabis to treat various medical conditions and symptoms, such as chronic pain, spasticity, and epilepsy. However, one of the biggest challenges is the assurance of a standardized cannabis product that contains a consistent amount of its main psychoactive substances delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), and which is compliant with predetermined specifications for these compounds. This is crucial not only to ensure consistent cannabis quality and dosage for patients but also to effectively translate research findings into clinical practice.

Methods

This systematic literature review provides an overview of the effects of standardized cannabis products from Bedrocan, a leading Dutch producer of pharmaceutical-quality standardized medicinal cannabis.

Results

Cannabis administration to healthy volunteers induces dose-dependent acute effects, such as rapidly rising THC and CBD blood concentrations, the subjective experience of high and anxiety, slower reaction time and impaired attention, learning and working memory. Patient studies suggest that treatment with medicinal cannabis reduces pain intensity across a broad range of chronic pain-related medical conditions. Medicinal cannabis showed a mild safety profile, with minor and transient side effects, such as feeling high, coughing and mental confusion. The strength of acute effects, the experience of side effects and the drop-out rate in patient studies may depend on cannabis dose, cannabis composition (CBD:THC ratio), and cannabis use history of participants.

Conclusion

Safety and efficacy of standardized medicinal cannabis products should be further investigated in randomized clinical trials with sufficient sample size, with particular focus on cannabis dose and composition, age and differences between males and females.

Examining the Impact of Simultaneous Alcohol and Cannabis Use on Alcohol Consumption and Consequences: Protocol for an Observational Ambulatory Assessment Study in Young Adults

BACKGROUND

There is significant conflicting evidence as to how using cannabis while drinking alcohol (ie, simultaneous alcohol and cannabis use) impacts alcohol volume consumed, patterns of drinking, and alcohol-related consequences. The impact of simultaneous use on drinking outcomes may be influenced by several within-person (eg, contextual) and between-person (individual) factors.

OBJECTIVE

This study was designed to examine naturalistic patterns of alcohol and cannabis use to understand how simultaneous use may impact drinking outcomes. The primary aims were to understand the following: (1) if simultaneous use is associated with increased alcohol consumption and riskier patterns of drinking, (2) if simultaneous use leads to increased alcohol consequences, and (3) how contextual circumstances moderate the impact of simultaneous use on consumption and consequences.

METHODS

Data collection involves a 28-day ambulatory assessment protocol in which a sample of non-treatment-seeking young adults who report simultaneous use of alcohol and cannabis complete ecological momentary assessments (random, event-contingent, and time-contingent surveys) of alcohol and cannabis use, contexts, motives, and consequences on their personal smartphones while continuously wearing an alcohol biosensor bracelet. Participants also complete a baseline assessment, brief internet-based check-in on day 14, and a final session on day 28. Community-based recruitment strategies (eg, social media and flyers) were used to enroll 95 participants to obtain a target sample of 80, accounting for attrition.

RESULTS

Recruitment and data collection began in May 2021 and continued through June 2024. Initial results for primary aims are expected in October 2024. As of March 2024, the project had recruited 118 eligible participants, of whom 94 (79.7%) completed the study, exceeding initial projections for the study time frame. Remaining recruitment will provide the capacity to probe cross-level interactions that were not initially statistically powered. Strengths of the project include rigorous data collection, good retention and compliance rates, faster-than-expected enrollment procedures, use of a novel alcohol biosensor, and successful adaptation of recruitment and data collection procedures during the COVID-19 pandemic.

CONCLUSIONS

This is the first investigation to assess the key momentary predictors and outcomes of simultaneous use as well as self-reported and objective (via alcohol biosensor) measures of alcohol consumption and patterns. The results of this study will inform prevention efforts and studies of individuals who use cannabis who are engaged in alcohol treatment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/58685.

Chronic cannabis use alters the spontaneous and oscillatory gamma dynamics serving cognitive control

Regular cannabis use is associated with cortex-wide changes in spontaneous and oscillatory activity, although the functional significance of such changes remains unclear. We hypothesized that regular cannabis use would suppress spontaneous gamma activity in regions serving cognitive control and scale with task performance. Participants (34 cannabis users, 33 nonusers) underwent an interview regarding their substance use history and completed the Eriksen flanker task during magnetoencephalography (MEG). MEG data were imaged in the time-frequency domain and virtual sensors were extracted from the peak voxels of the grand-averaged oscillatory interference maps to quantify spontaneous gamma activity during the pre-stimulus baseline period. We then assessed group-level differences in spontaneous and oscillatory gamma activity, and their relationship with task performance and cannabis use metrics. Both groups exhibited a significant behavioral flanker interference effect, with slower responses during incongruent relative to congruent trials. Mixed-model ANOVAs indicated significant gamma-frequency neural interference effects in the left frontal eye fields (FEF) and left temporoparietal junction (TPJ). Further, a group-by-condition interaction was detected in the left FEF, with nonusers exhibiting stronger gamma oscillations during incongruent relative to congruent trials and cannabis users showing no difference. In addition, spontaneous gamma activity was sharply suppressed in cannabis users relative to nonusers in the left FEF and TPJ. Finally, spontaneous gamma activity in the left FEF and TPJ was associated with task performance across all participants, and greater cannabis use was associated with weaker spontaneous gamma activity in the left TPJ of the cannabis users. Regular cannabis use was associated with weaker spontaneous gamma in the TPJ and FEF. Further, the degree of use may be proportionally related to the degree of suppression in spontaneous activity in the left TPJ.

Effects of acute cannabis inhalation on reaction time, decision-making, and memory using a tablet-based application

BACKGROUND

Acute cannabis use has been demonstrated to slow reaction time and affect decision-making and short-term memory. These effects may have utility in identifying impairment associated with recent use. However, these effects have not been widely investigated among individuals with a pattern of daily use, who may have acquired tolerance. The purpose of this study was to examine the impact of tolerance to cannabis on the acute effects as measured by reaction time, decision-making (gap acceptance), and short-term memory.

METHODS

Participants (ages 25-45) completed a tablet-based (iPad) test battery before and approximately 60 min after smoking cannabis flower. The change in performance from before to after cannabis use was compared across three groups of cannabis users: (1) occasional use (n = 23); (2) daily use (n = 31); or (3) no current use (n = 32). Participants in the occasional and daily use group self-administered ad libitum, by smoking or vaping, self-supplied cannabis flower with a high concentration of total THC (15-30%).

RESULTS

The occasional use group exhibited decrements in reaction time (slowed) and short-term memory (replicated fewer shapes) from before to after cannabis use, as compared to the no-use group. In the gap acceptance task, daily use participants took more time to complete the task post-smoking cannabis as compared to those with no use or occasional use; however, the level of accuracy did not significantly change.

CONCLUSIONS

The findings are consistent with acquired tolerance to certain acute psychomotor effects with daily cannabis use. The finding from the gap acceptance task which showed a decline in speed but not accuracy may indicate a prioritization of accuracy over response time. Cognitive and psychomotor assessments may have utility for identifying impairment associated with recent cannabis use.

Nabilone Impairs Spatial and Verbal Working Memory in Healthy Volunteers

Background: Memory impairments and psychosis-like experiences can be adverse effects of cannabis use. However, reports on the cognitive impact of cannabis use are not consistent. There are also limited studies on the psychotomimetic effects of cannabinoid compounds to reveal the association between cannabis and psychosis. Therefore, we investigated the effect of acute cannabinoid intoxication on verbal working memory (VWM) and spatial working memory (SWM) following oral doses of the synthetic cannabinoid agonist, nabilone (1-2 mg, oral). We further investigated the effect of nabilone on psychosis-like experiences (schizotypy scores) and associations of schizotypy with VWM and SWM. Methods: Healthy participants (n=28) completed spatial and digit span tasks across different delay conditions (0, 6, 12, and 18 sec) after receiving nabilone (1-2 mg, PO) or placebo in a randomized, double-blind, counterbalanced, crossover manner. A subset of participants completed a short battery of schizotypy measures (n=25). Results: Nabilone impaired VWM (p=0.03, weak effect size η2=0.02) and SWM (p=0.00016, η2=0.08). Nabilone did not significantly change overall schizotypy scores. Schizotypy scores were negatively correlated with working memory (WM) averaged across all delays and both modalities, under placebo (ρ=-0.41, p=0.04). In addition, there were significant negative correlations between occasions of cannabis use and overall WM averaged scores across drug treatments (ρ=-0.49, p=0.007) and under placebo (ρ=-0.45, p=0.004). The results showed that the drug effect in the less frequent cannabis users was more pronounced on the SWM (p<0.01) and VWM (p<0.01), whereas there appeared to be little drug effect in the frequent cannabis users. Conclusion: Low doses of synthetic cannabinoid impaired SWM and VWM, indicating that exogenous activation of the cannabinoid system influences cognitive performance. Further, the results replicated previous findings that schizotypy is correlated with deficits in WM. Clinical Trial Registry Name: Nabilone and caffeine effects on the perceptions of visually, auditory, tactile and multimodal illusions in healthy volunteers. Clinical Trial Registration Number: CT-2018-CTN-02561 (Therapeutic Goods Administration Clinical Trial Registry) and ACTRN12618001292268 (The Australian New Zealand Clinical Trials Registry).

Cannabis and Cannabinoids in the Perioperative Period

Cannabis use is increasingly common, and with a growing number of jurisdictions implementing legalization frameworks, it is likely that providers will encounter more patients who use cannabis. Therefore, it is important for providers to understand the implications of cannabis use and practical considerations for the perioperative period. Cannabis affects multiple organ systems and may influence intraoperative anesthesia, as well as postoperative pain management. The effects of cannabis and key anesthetic considerations are reviewed here.

Cannabinoids, Endocannabinoids, and Synthetic Cannabimimetic Molecules in Neuromuscular Disorders

Neuromuscular disorders (NMDs) encompass a large heterogeneous group of hereditary and acquired diseases primarily affecting motor neurons, peripheral nerves, and the skeletal muscle system. The symptoms of NMDs may vary depending on the specific condition, but some of the most common ones include muscle weakness, pain, paresthesias, and hyporeflexia, as well as difficulties with swallowing and breathing. NMDs are currently untreatable. Therapeutic options include symptomatic and experimental medications aimed at delaying and alleviating symptoms, in some cases supplemented by surgical and physical interventions. To address this unmet medical need, ongoing research is being conducted on new treatments, including studies on medical cannabis, endocannabinoids, and related molecules with cannabimimetic properties. In this context, a significant amount of knowledge about the safety and effectiveness of cannabinoids in NMDs has been obtained from studies involving patients with multiple sclerosis experiencing pain and spasticity. In recent decades, numerous other preclinical and clinical studies have been conducted to determine the potential benefits of cannabinoids in NMDs. This review article aims to summarize and provide an unbiased point of view on the current knowledge about the use of cannabinoids, endocannabinoids, and synthetic analogs in NMDs, drawing from an array of compelling studies.

Time- and temperature-dependent postmortem ∆9-tetrahydrocannabinol concentration changes in rabbits following controlled inhaled cannabis administration

ostmortem redistribution (PMR), a well-known phenomenon in forensic toxicology, can result in substantial changes in drug concentrations after death, depending on the chemical characteristics of the drug, blood collection site, storage conditions of the body and postmortem interval (PMI). Limited PMR data are available for ∆9-tetrahydrocannabinol (THC), the primary psychoactive component in Cannabis sativa. PMR was evaluated after controlled cannabis inhalation via a smoking machine and exposure chamber in New Zealand white rabbits. Necropsies were performed on five control rabbits immediately after euthanasia, whereas 27 others were stored at room temperature (21°C) or refrigerated conditions (4°C) until necropsy at 2, 6, 16, 24 or 36 h after death. THC and its Phase I and glucuronidated Phase II metabolites were quantified in blood, vitreous humor, urine, bile and tissues by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Under refrigerated temperature, heart blood THC concentrations significantly increased at PMI 2 h in rabbits, whereas peripheral blood THC concentrations showed a significant increase at PMI 16 h. Central:peripheral blood and liver:peripheral blood ratios for THC ranged from 0.13 to 4.1 and 0.28 to 8.9, respectively. Lung revealed the highest THC concentrations, while brain and liver exhibited the most stable THC concentrations over time. This report contributes much needed data to our understanding of postmortem THC behavior and can aid toxicologists in the interpretation of THC concentrations in medicolegal death investigations.

Mechanisms of Injury in Adolescent Trauma Patients With a Positive Marijuana Screen

BACKGROUND

Marijuana use among adolescents may have increased after its legalization in the United States. An association between violence and marijuana use in adults has been demonstrated in previous reports. We hypothesized that adolescent trauma patients presenting with a positive marijuana screen (pMS) are more likely to have been injured by gunfire or knives and will have more severe injuries overall, compared to patients with a negative marijuana screen (nMS).

METHODS

The 2017 Trauma Quality Improvement Program database was queried for adolescent (13-17 years old) pMS patients and compared to adolescents who tested negative for all substance/alcohol. Patients with positive polysubstance/alcohol were excluded.

RESULTS

From 8257 adolescent trauma patients, 2060 (24.9%) had a pMS with a higher rate of males in the pMS group (76.3% vs 64.3%, P < .001). The pMS group presented more frequently after gun (20.3% vs 7.9%, P < .001) or knife trauma (5.7% vs 3.0%, P < .001) and less frequently after falls (8.9% vs 15.6%, P < .001) and bicycle collisions (3.3% vs 4.8%, P = .002). The rate of serious thoracic injury (AIS ≥3) was higher for pMS patients (16.7% vs 12.0%, P < .001), and more pMS patients required emergent operation (14.9% vs 10.6%, P < .001).

DISCUSSION

In our adolescent patient population, one quarter tested positive for marijuana. These patients are more likely to be injured by guns and/or knives suffering serious injuries, and often require immediate operative intervention. A marijuana cessation program for adolescents can help improve outcomes in this high-risk patient group.

Cognitive test performance in chronic cannabis flower users, concentrate users, and non-users

Extremely high-potency cannabis concentrates are becoming increasingly available and popular among consumers. While prior research indicates these products are perceived to have greater detrimental effects relative to cannabis flower, few studies have examined their relative objective effects, and no existing studies have compared the cognitive test performance of sober flower users, concentrate users, and non-users. A total of 198 healthy adults (98 non-users, 46 exclusive flower users, and 54 concentrate users) were administered a battery of tests of memory, psychomotor speed, attention, and executive functioning under sober laboratory-controlled conditions. Significant group differences were detected on tests of verbal free recall and episodic prospective memory, with both the flower users and concentrate users demonstrating significantly worse performance than non-users. Concentrate (but not flower) users performed worse than non-users on a measure of source memory, but contrary to our hypothesis, there were no significant differences between flower and concentrate users on any of the cognitive tests. Results indicate that, under sober conditions, individuals who regularly use concentrates are no more cognitively impacted than those who exclusively use flower. These null findings may reflect the tendency for concentrate users to self-titrate and use significantly lower quantities of concentrates than flower.

Blood cannabinoid molar metabolite ratios are superior to blood THC as an indicator of recent cannabis smoking

INTRODUCTION

Cannabis use is a growing concern in transportation and workplace incidents. Because Δ9-tetrahydrocannabinol is detectable after acute psychoactive effects have resolved, it has limitations as an indicator of recent usage or potential impairment.

METHODS

In an observational study of driving and psychomotor performance, we measured whole blood Δ9-tetrahydrocannabinol plus its metabolites 11-hydroxy-Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol by liquid chromatography with tandem mass spectrometry at baseline and 30 min after starting a 15-minute interval of smoking cannabis in 24 occasional and 32 daily cannabis smokers. We calculated two blood cannabinoid molar metabolite ratios: 1) [Δ9-tetrahydrocannabinol] to [11-nor-9-carboxy-Δ9-tetrahydrocannabinol] and 2) ([Δ9-tetrahydrocannabinol] + [11-hydroxy-Δ9-tetrahydrocannabinol]) to [11-nor-9-carboxy-Δ9-tetrahydrocannabinol]. We compared these to blood [Δ9-tetrahydrocannabinol] alone as indicators of recent cannabis smoking.

RESULTS

Median Δ9-tetrahydrocannabinol concentrations increased from 0 ( 0.38). By comparison, a cut-point for Δ9-tetrahydrocannabinol of 5.3 µg/L yielded 88% specificity, 73% sensitivity, and 80% accuracy.

CONCLUSIONS

In occasional and daily users, the blood cannabinoid molar metabolite ratios were superior to whole blood Δ9-tetrahydrocannabinol as indicators of recent cannabis smoking. We recommend measurement and reporting of Δ9-tetrahydrocannabinol, 11-hydroxy-Δ9-tetrahydrocannabinol, and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol, and their molar metabolite ratios in forensic and safety investigations.

Impaired inhibition after delta-9-tetrahydrocannabinol in women not related to circulating estradiol levels

Cannabis and its main psychoactive constituent, delta-9-tetrahydrocannabinol (THC), impair cognitive processes, including the ability to inhibit inappropriate responses. However, responses to cannabinoid drugs vary widely, and little is known about the factors that influence the risk for adverse effects. One potential source of variation in response to cannabinoids in women is circulating ovarian hormones such as estradiol and progesterone. Whereas there is some evidence that estradiol affects responses to cannabinoids in rodents, little is known about such interactions in humans. Here, we investigate whether variations in estradiol levels across the follicular phase of the menstrual cycle modulate the effect of THC on inhibitory control in healthy women. Healthy female occasional cannabis users (N = 60) received THC (7.5 mg and 15 mg, oral) and placebo during either the early follicular phase, when estradiol levels are low, or the late follicular phase, when estradiol levels are higher. They completed a Go/No Go (GNG) task at the time of peak drug effect. We hypothesized that the effects of THC on GNG performance would be greater when estradiol levels were elevated. As expected, THC impaired GNG task performance: it increased response time and errors of commission/false alarms and decreased accuracy, relative to placebo. However, these impairments were not related to estradiol levels. These results suggest that THC-induced impairments in inhibitory control are not affected by cycle-related fluctuations in estradiol levels.

Measuring white matter microstructure in 1,457 cannabis users and 1,441 controls: A systematic review of diffusion-weighted MRI studies

INTRODUCTION

Cannabis is the most widely used regulated substance by youth and adults. Cannabis use has been associated with psychosocial problems, which have been partly ascribed to neurobiological changes. Emerging evidence to date from diffusion-MRI studies shows that cannabis users compared to controls show poorer integrity of white matter fibre tracts, which structurally connect distinct brain regions to facilitate neural communication. However, the most recent evidence from diffusion-MRI studies thus far has yet to be integrated. Therefore, it is unclear if white matter differences in cannabis users are evident consistently in selected locations, in specific diffusion-MRI metrics, and whether these differences in metrics are associated with cannabis exposure levels.

METHODS

We systematically reviewed the results from diffusion-MRI imaging studies that compared white matter differences between cannabis users and controls. We also examined the associations between cannabis exposure and other behavioral variables due to changes in white matter. Our review was pre-registered in PROSPERO (ID: 258250; https://www.crd.york.ac.uk/prospero/).

RESULTS

We identified 30 diffusion-MRI studies including 1,457 cannabis users and 1,441 controls aged 16-to-45 years. All but 6 studies reported group differences in white matter integrity. The most consistent differences between cannabis users and controls were lower fractional anisotropy within the arcuate/superior longitudinal fasciculus (7 studies), and lower fractional anisotropy of the corpus callosum (6 studies) as well as higher mean diffusivity and trace (4 studies). Differences in fractional anisotropy were associated with cannabis use onset (4 studies), especially in the corpus callosum (3 studies).

DISCUSSION

The mechanisms underscoring white matter differences are unclear, and they may include effects of cannabis use onset during youth, neurotoxic effects or neuro adaptations from regular exposure to tetrahydrocannabinol (THC), which exerts its effects by binding to brain receptors, or a neurobiological vulnerability predating the onset of cannabis use. Future multimodal neuroimaging studies, including recently developed advanced diffusion-MRI metrics, can be used to track cannabis users over time and to define with precision when and which region of the brain the white matter changes commence in youth cannabis users, and whether cessation of use recovers white matter differences.

SYSTEMATIC REVIEW REGISTRATION

www.crd.york.ac.uk/prospero/, identifier: 258250.

Consumer Experiences with Delta-8-THC: Medical Use, Pharmaceutical Substitution, and Comparisons with Delta-9-THC

Introduction: Cannabis products containing delta-8-THC became widely available in most of the United States in late 2020 and rapidly became a significant source of revenue for hemp processing companies, especially in states where use of delta-9-THC remains illegal or requires professional authorization for medical use. Scientific research on the use of delta-8-THC is scarce, previous clinical studies included a combined total of 14 participants, leading some state governments to prohibit it until its properties and effects are better understood. Methods: Researchers developed an online survey for delta-8-THC consumers addressing a broad range of issues regarding delta-8-THC, including use for the treatment of health and medical conditions. Previous survey studies on the medical use of cannabis and cannabis products informed survey components. Results: Patterns of delta-8-THC use had both similarities with and differences from the use of delta-9-THC cannabis and products. Administration methods were primarily edibles (64%) and vaping concentrates (48%). About half of the participants (51%) used delta-8-THC to treat a range of health and medical conditions, primarily anxiety or panic attacks (69%), stress (52%), depression or bipolar disorder (46%), and chronic pain (41%). Participants compared delta-8-THC very favorably with both delta-9-THC and pharmaceutical drugs and reported substantial levels of substitution for both. Most participants did not inform their primary care provider of their delta-8-THC use (78%) and were not confident of their primary care provider's ability to integrate medical cannabis into their treatment (70%). Knowledge of effective dosages was low, and participants' knowledge of delta-8-THC was primarily from the Internet and their own experiences. Conclusion: Harm reduction is a central component of public health. Although the legal environment is becoming more restrictive for delta-8-THC in comparison to delta-9-THC, results suggest that delta-8-THC may be equally effective for desired purposes of cannabis use and lower in undesirable or adverse effects. All policies and practices should be informed by empirical evidence. Considerable research will be needed to systematically verify the patterns reported by participants, and collaborations among academic researchers, government, and the cannabis industry may be valuable in developing the knowledge base for delta-8-THC and other cannabinoids.

Cannabis use in Attention - Deficit/Hyperactivity Disorder (ADHD): A scoping review

INTRODUCTION

Treatments for Adult ADHD include stimulants, two non-stimulant medications, as well as cognitive-behavioral therapy (CBT). These pharmacological agents are often associated with side effects, contributing to poor treatment adherence. Patients with ADHD have regularly stated that cannabis has helped improve their ADHD symptoms; however, scientific literature describing the effects of cannabis on symptoms of ADHD is scarce.

METHODS

We systematically searched MEDLINE, EMBASE, EMCARE, PsycINFO, Web of Science, Cochrane Library, and Clinicaltrials.gov. The searches included all publications in English up to June 27, 2022. We included both experimental and observational studies that assessed the effect of cannabis on ADHD symptomatology and neuropsychiatric outcomes. To synthesize our current understanding of the potential effects of cannabis use on ADHD symptoms and pathophysiology, and the effects of ADHD on cannabis use, data was extracted from each study regarding the characteristics of its population, methods used to assess both cannabis consumption and ADHD symptoms, and key findings.

RESULTS

Our scoping review included a total of 39 studies. Only one study employed a randomized and placebo-controlled design to directly measure the effect of cannabis on ADHD, and no significant effect was observed for the study's primary outcome, the QbTest (Est = -0.17, 95% CI -0.40 to 0.07, p = 0.16). Most of the literature consists of cross-sectional studies that evaluate the association between ADHD severity and cannabis use. 15 studies addressed the neuropsychiatric effects of cannabis on ADHD by employing either a battery of neuropsychiatric tests or neuroimaging. The concentration and amount of THC and CBD used were not well measured in most of the studies. Although some studies indicated that cannabis improved ADHD symptoms, most studies indicated it worsened or had no effect on ADHD symptoms.

CONCLUSIONS

Given the current evidence, cannabis is not recommended for people with ADHD. Limitations of the literature include the absence of objective measurements for cannabis exposure and ADHD symptoms, heterogenous definitions, oversampling, and small sample sizes.

Cannabis and Driving: Developing Guidelines for Safety Policies

INTRODUCTION

The dynamism in the regulatory frameworks concerning the consumption of cannabinoids has placed their effects on cognitive and psychomotor skills at the center of the scientific debate. In consideration of the potential repercussions on public safety, particular attention has been focused on the impairment of driving skills, opening up the need to specifically regulate driving under the effects of cannabinoids.

PHARMACOKINETICS

Both native cannabinoids and metabolites show a long positivity at low concentrations in the biological fluids, especially in the case of chronic consumption. Qualitative positivity to cannabinoids does not itself prove the presence of detrimental effects, which require the presence of active substances at relevant concentrations. Driving Skill Impairment: Multiple studies highlight a tetrahydrocannabinol (THC) concentration- based alteration of driving skills mainly affecting automatisms, whereas skills subjected to cognitive control are preserved up to higher dosages. The evidence relating to associations with other substances, chronic consumption and other cannabinoids, on the other hand, is still burdened by a high degree of uncertainty. Regulation Policies: Different models can be adopted in the regulation of driving under the effects of cannabinoids: sanctions can be applied in case of qualitative positivity, cannabinoids concentration above a defined threshold, or in presence of a demonstrated state of cognitive alteration.

CONCLUSION

"Per se limit" with a quantitative THC cut-off between 3.5 and 5 ng/ml can currently be considered the most balanced choice. Finally, the analysis carried out allowed to identify pitfalls in both scientific and legislative fields for the improvement of safety policies.

Assessing Health Care Providers' Knowledge of Medical Cannabis

Introduction: Many health care providers would benefit from greater knowledge and awareness of medical cannabis, even if they choose not to integrate it into their medical practice. Unfortunately, health care providers generally report low knowledge of medical cannabis and cite this lack of knowledge as a barrier to making patient recommendations. It is important to understand health care providers' medical cannabis knowledge and its correlates. However, few studies have rigorously assessed clinically relevant cannabis-related knowledge, instead typically focusing on attitudes toward cannabis and perceived knowledge. Methods: Physicians in a university-affiliated health system completed an anonymous online survey. The survey assessed participants' basic demographics and medical experience, experiences with cannabis education, beliefs about their knowledge of and competency regarding medical cannabis, and knowledge of medical cannabis in relation to the current scientific evidence. Results: The average level of medical cannabis knowledge was 58% correct, with scores ranging from 39% to 78% correct. Perceived cannabis knowledge predicted actual knowledge, and those who pursued self-initiated study or attended a lecture on medical cannabis had higher knowledge levels. Conclusion: Levels of factual knowledge about medical cannabis among physicians were moderate. Our results highlight the mismatch between physician knowledge and cannabis policy. We offer our brief, 10-min assessment as a baseline for characterizing cannabis knowledge, acknowledging that the content and interpretation may change as knowledge advances.

Remote detection of Cannabis-related impairments in performance?

RATIONALE

Researchers have traditionally studied the effects of psychoactive drugs such as Cannabis in controlled laboratory settings or relied on retrospective self-reports to measure impairment. However, advances in technology afford opportunities to conduct assessments remotely.

OBJECTIVES

We considered whether objective click-stream data (time and number of clicks spent on a webpage) during an online survey could supplement self-reports of substance use problems.

METHODS

The clickstream data of participants (n = 236) were examined as they completed an online study which included validated psychometric tests (Cannabis Use Disorders Identification Test-Revised, Grit-O, Kessler Psychological Distress Scale, and Brief Self Control Scale). Clickstream data were compared to self-reported Cannabis use.

RESULTS

People reporting Cannabis use within the last 4 weeks required more time and more clicks to complete the online survey, and this was specifically associated with reported frequency of use, duration of impairment, and problems with memory and concentration. Longer amounts of time and more clicks on the online questionnaire were associated with more recent Cannabis use rather than demographic factors or stimulant use.

CONCLUSIONS

These results imply clickstream data remotely detected indecision or other deficits associated with previous Cannabis use.

Psychotomimetic symptoms after a moderate dose of a synthetic cannabinoid (JWH-018): implications for psychosis

BACKGROUND

Synthetic cannabinoids (SCs) are the largest class of novel psychoactive substances (NPS) and are associated with an increased risk of overdosing and adverse events such as psychosis. JWH-018 is one of the earliest SCs and still widely available in large parts of the world. Controlled studies to assess the safety and behavioural profiles of SCs are extremely scarce.

AIM

The current study was designed to assess the psychotomimetic effects of a moderate dose of JWH-018.

METHODS

Twenty-four healthy participants (10 males, 14 females) entered a placebo-controlled, double blind, within-subjects trial and inhaled vapour of placebo or 75μg/kg bodyweight JWH-018. To ascertain a minimum level of intoxication, a booster dose of JWH-018 was administered on an as-needed basis. The average dose of JWH-018 administered was 5.52 mg. Subjective high, dissociative states (CADSS), psychedelic symptoms (Bowdle), mood (POMS) and cannabis reinforcement (SCRQ) were assessed within a 4.5-h time window after drug administration.

RESULTS

JWH-018 caused psychedelic effects, such as altered internal and external perception, and dissociative effects, such as amnesia, derealisation and depersonalisation and induced feelings of confusion.

CONCLUSION

Overall, these findings suggest that a moderate dose of JWH-018 induces pronounced psychotomimetic symptoms in healthy participants with no history of mental illness, which confirms that SCs pose a serious risk for public health.

Functional brain connectomes reflect acute and chronic cannabis use

Resting state fMRI has been employed to identify alterations in functional connectivity within or between brain regions following acute and chronic exposure to Δ9-tetrahydrocannabinol (THC), the psychoactive component in cannabis. Most studies focused a priori on a limited number of local brain areas or circuits, without considering the impact of cannabis on whole-brain network organization. The present study attempted to identify changes in the whole-brain human functional connectome as assessed with ultra-high field (7T) resting state scans of cannabis users (N = 26) during placebo and following vaporization of cannabis. Two distinct data-driven methodologies, i.e. network-based statistics (NBS) and connICA, were used to identify changes in functional connectomes associated with acute cannabis intoxication and history of cannabis use. Both methodologies revealed a broad state of hyperconnectivity within the entire range of major brain networks in chronic cannabis users compared to occasional cannabis users, which might be reflective of an adaptive network reorganization following prolonged cannabis exposure. The connICA methodology also extracted a distinct spatial connectivity pattern of hypoconnectivity involving the dorsal attention, limbic, subcortical and cerebellum networks and of hyperconnectivity between the default mode and ventral attention network, that was associated with the feeling of subjective high during THC intoxication. Whole-brain network approaches identified spatial patterns in functional brain connectomes that distinguished acute from chronic cannabis use, and offer an important utility for probing the interplay between short and long-term alterations in functional brain dynamics when progressing from occasional to chronic use of cannabis.

Driving After Cannabis Use Among Young Adults in Michigan

Introduction: Driving after cannabis use is associated with a number of risks. Examination of driving after cannabis use among young adults is particularly important, as young adults have the highest rates of cannabis use and among the highest rates of traffic crashes. The current study examines rates and correlates of driving after cannabis use among young adults (aged 18-25) who reported past month cannabis use. Methods: Participants were from Michigan and recruited through paid Facebook and Instagram advertisements between February and March 2018 (n=461). Results: Nearly a third (31.9%) of the sample reported driving after cannabis use in the past month. Young adults who were employed (aOR=1.872, p=0.045), had medical cannabis cards (aOR=2.877, p<0.001), endorsed coping reasons for use (aOR=2.992, p=0.007), and endorsed social/recreational reasons for use (aOR=1.861, p=0.034) had greater odds of driving after cannabis use. Students had lower odds of driving after use (aOR=0.573, p=0.011). Conclusions: Employment and having a medical cannabis card may be important risk markers for identifying individuals more likely to drive after use of cannabis. Prevention efforts could provide psychoeducation at dispensaries to individuals with medical cannabis cards about the risks of driving after use. Coping motives for cannabis use may also be useful in identifying young adults at the greatest risk of driving after use of cannabis.

The Effects of a Single Transcranial Direct Current Stimulation Session on Impulsivity and Risk Among a Sample of Adult Recreational Cannabis Users

Individuals with substance use disorders exhibit risk-taking behaviors, potentially leading to negative consequences and difficulty maintaining recovery. Non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) have yielded mixed effects on risk-taking among healthy controls. Given the importance of risk-taking behaviors among substance-using samples, this study aimed to examine the effects of tDCS on risk-taking among a sample of adults using cannabis. Using a double-blind design, 27 cannabis users [M(SD) age = 32.48 (1.99), 41% female] were randomized, receiving one session of active or sham tDCS over the bilateral dorsolateral prefrontal cortex (dlPFC). Stimulation parameters closely followed prior studies with anodal right dlPFC and cathodal left dlPFC stimulation. Risk-taking-assessed via a modified Cambridge Gambling Task-was measured before and during tDCS. Delay and probability discounting tasks were assessed before and after stimulation. No significant effects of stimulation on risk-taking behavior were found. However, participants chose the less risky option ∼86% of the trials before stimulation which potentially contributed to ceiling effects. These results contradict one prior study showing increased risk-taking among cannabis users following tDCS. There was a significant increase in delay discounting of a $1000 delayed reward during stimulation for the sham group only, but no significant effects for probability discounting. The current study adds to conflicting and inconclusive literature on tDCS and cognition among substance-using samples. In conclusion, results suggest the ineffectiveness of single session dlPFC tDCS using an established stimulation protocol on risk-taking, although ceiling effects at baseline may have also prevented behavior change following tDCS.

Analysis of the therapeutic effect of Dimu Ningshen (TCM formula) on attention deficit hyperactivity disorder based on gut microbiota and serum metabolomics

Background

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder diagnosed during adolescence and adulthood. Assessment of the long-term risks of the current drugs for ADHD treatment has been insufficient, and little is known concerning the long-term therapeutic effects of psychostimulants. Commercially available traditional Chinese medicine compound oral preparations [e.g., Dimu Ningshen (DMNS)] have been widely used in the clinical treatment of ADHD, but their influence on the interaction between gut microbes and potential metabolomes remains inconclusive.

Methods

We used a series of behavioral experiments to evaluate the behavioral effects of DMNS on adolescent and adult ADHD rats and used 16S rDNA sequencing of gut microbes and nontarget metabolomics to evaluate the potential pathogenesis of ADHD and explore the biological mechanism of DMNS in ADHD treatment.

Results

For the first time, DMNS was shown to reduce the excessive activity of adult and adolescent ADHD rats and improve the attention deficit of adult ADHD rats. DMNS improved the structural composition of the ADHD gut microbiota and reduced the abundance of Ruminococcaceae_NK4A214_group, Ruminococcus_2, and Eubacterium_nodatum_group. Simultaneously, DMNS increased the circulating levels of peripheral monoamine neurotransmitter precursors (e.g., phenylalanine) and reduced the circulating levels of peripheral fatty acid amides (e.g., oleamide). Finally, the changes in the ADHD serum metabolites were strongly correlated with the gut microbiota.

Conclusion

DMNS has a good effect in treating ADHD, and it may exert this effect by regulating the gut microbiota and affecting metabolites in the peripheral circulation.

A Comparison of Acute Neurocognitive and Psychotomimetic Effects of a Synthetic Cannabinoid and Natural Cannabis at Psychotropic Dose Equivalence

Due to differences in potency, efficacy, and affinity for CB1 receptors, similarities and differences in psychoactive effect profiles of natural cannabis and synthetic cannabinoids (SCs) cannot reliably be derived from equipotent dose comparisons. Instead, the current study proposes to compare the intrinsic psychoactive effects of natural cannabis (THC) and an SC, JWH-018, at psychotropic dose equivalence. Participants from two placebo-controlled studies were matched for their levels of subjective high to compare neurocognitive and psychotomimetic effects of THC and JWH-018. At equal subjective intoxication levels, both drugs impaired psychomotor, divided attention, and impulse control, with no significant difference between the two drugs. Both drugs also caused significant psychotomimetic effects, but dissociative effects were considerably more pronounced for JWH-018 than THC. We conclude that psychotropic dose equivalence provides a uniform approach for comparing the neurocognitive and psychotomimetic profiles of CB1 agonists, which can also be applied to other drug classes.

Mechanisms of cannabis impairment: Implications for modeling driving performance

Past research on cannabis has been limited in scope to THC potencies lower than legally available and efforts to integrate the effects into models of driving performance have not been attempted to date. The purpose of this systematic review is to understand the implications for modeling driving performance and describe future research needs. The risk of motor vehicle crashes increases 2-fold after smoking marijuana. Driving during acute cannabis intoxication impairs concentration, reaction time, along with a variety of other necessary driving-related skills. Changes to legislation in North America and abroad have led to an increase in cannabis' popularity. This has given rise to more potent strains, with higher THC concentrations than ever before. There is also rising usage of novel ingestion methods other than smoking, such as oral cannabis products (e.g., brownies, infused drinks, candies), vaping, and topicals. The PRISMA guidelines were followed to perform a systematic search of the PubMed database for peer-reviewed literature. Search terms were combined with keywords for driving performance: driving, performance, impairment. Grey literature was also reviewed, including congressional reports, committee reports, and roadside surveys. There is a large discrepancy between the types of cannabis products sold and what is researched. Almost all studies that used inhalation as the mode of ingestion with cannabis that is around 6% THC. This pales in comparison to the more potent strains being sold today which can exceed 20%. Which is to say nothing of extracts, which can contain 60% or more THC. Experimental protocol is another gap in research that needs to be filled. Methodologies that involve naturalistic (real world) driving environments, smoked rather than vaporized cannabis, and non-lab certified products introduce uncontrollable variables. When considering the available literature and the implications of modeling the impacts of cannabis on driving performance, two critical areas emerge that require additional research: The first is the role of cannabis potency. Second is the route of administration. Does the lower peak THC level result in smaller impacts on performance? How long does potential impairment last along the longer time-course associated with different pharmacokinetic profiles. It is critical for modeling efforts to understand the answers to these questions, accurately model the effects on driver performance, and by extension understand the risk to the public.

Neurological Soft Signs in Cannabis Use Disorder with or without Psychosis: A Comparative Study from India

OBJECTIVE

The purpose of this study was to assess and compare neurological soft signs in patients of cannabis use disorder (CUD) with and without co-occurring psychosis in a treatment-seeking sample.

METHODS

We included 30 right-handed male subjects aged 18-65 years diagnosed with CUD (as per DSM-5) without any co-occurring psychiatric disorder in group I and those with co-occurring non-affective psychosis in group II. Group III consisted of 30 age and sex-matched, right-handed, healthy subjects with no psychiatric or medical conditions. Neurological Evaluation Scale (NES) was applied to measure neurological soft signs across the groups. We also used the Severity of Dependence Scale (in CUD with or without co-occurring non-affective psychosis groups) and Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms, Barnes Akathisia Rating Scale, Abnormal Involuntary Movements Scale, and Simpson Angus Scale (in CUD with co-occurring non-affective psychosis group) .

RESULTS

Our data suggested higher total NES mean scores in CUD with (20.53 ± 13.77) or without co-occurring non-affective psychosis groups (15.93 ± 9.86) as compared to healthy controls (6.20 ± 5.40) (χ² = 23.12; p < .001). However, there were no differences between cannabis use disorder with or without co-occurring non-affective psychosis groups. The mean of subdomain scores of motor incoordination, sequencing of complex motor tasks, sensory integration, and others was significantly higher in CUD with or without co-occurring non-affective psychosis groups compared to healthy controls.

CONCLUSION

Impairment in neurological soft signs is present in patients with CUD regardless of a co-occurring psychosis. Cannabinoids might be interacting with the brain circuits known to be involved in schizophrenia.

Assessing Cannabis Use Disorder in Medical Cannabis Patients: Interim Analyses from an Observational, Longitudinal Study

Background

To date, no studies have directly assessed potential cannabis use disorder (CUD) in medical cannabis (MC) patients pre- vs post-MC treatment. Given that MC patients use cannabis for symptom alleviation rather than intoxication, we hypothesized that MC patients would exhibit few symptoms of CUD after initiating MC treatment.

Methods

As part of an ongoing observational, longitudinal study, 54 MC patients completed baseline assessments prior to initiating MC use and returned for at least one follow-up assessment after three, six, and/or twelve months of a self-selected MC treatment regimen; detailed MC treatment information was collected and quantified. All patients completed the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) at each visit. Changes in individual items scores and total scores were assessed over time, and we examined whether total CUDIT-R scores correlated with frequency of MC use, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) exposure. Further, Cronbach's alpha analyses were conducted to provide preliminary data regarding the psychometric properties of the CUDIT-R when used among MC patients.

Results

Although total CUDIT-R scores increased relative to baseline, on average, ratings fell below the 'hazardous use' threshold at each visit. Analyses of individual items revealed that increases in total scores were primarily attributable to increases in frequency of use and not necessarily other aspects of problematic use. Total CUDIT-R scores were not associated with number of MC uses or CBD exposure, but a significant relationship was detected between increased THC exposure and higher CUDIT-R scores. Importantly however, analyses revealed that the CUDIT-R does not appear to be an appropriate tool for identifying CUD in MC patients.

Conclusions

Screening tools specifically designed to assess CUD in MC patients are needed and should distinguish between frequent use and problematic use; exposure to individual cannabinoids must also be considered.

Cannabis and Driving

As more states in the U.S legalize recreational and medicinal cannabis, rates of driving under the influence of this drug are increasing significantly. Aspects of this emerging public health issue potentially pit science against public policy. The authors believe that the legal cart is currently significantly ahead of the scientific horse. Issues such as detection procedures for cannabis-impaired drivers, and use of blood THC levels to gauge impairment, should rely heavily on current scientific knowledge. However, there are many, often unacknowledged research gaps in these and related areas, that need to be addressed in order provide a more coherent basis for public policies. This review focuses especially on those areas. In this article we review in a focused manner, current information linking cannabis to motor vehicle accidents and examine patterns of cannabis-impairment of driving related behaviors, their time courses, relationship to cannabis dose and THC blood levels, and compare cannabis and alcohol-impaired driving patterns directly. This review also delves into questions of alcohol-cannabis combinations and addresses the basis for of per-se limits in cannabis driving convictions. Finally, we distinguish between areas where research has provided clear answers to the above questions, areas that remain unclear, and make recommendations to fill gaps in current knowledge.

An Observational, Longitudinal Study of Cognition in Medical Cannabis Patients over the Course of 12 Months of Treatment: Preliminary Results

OBJECTIVE

Cannabis use has increased dramatically across the country; however, few studies have assessed the long-term impact of medical cannabis (MC) use on cognition. Studies examining recreational cannabis users generally report cognitive decrements, particularly in those with adolescent onset. As MC patients differ from recreational consumers in motives for use, product selection, and age of onset, we assessed cognitive and clinical measures in well-characterized MC patients over 1 year. Based on previous findings, we hypothesized MC patients would not show decrements and might instead demonstrate improvements in executive function over time.

METHOD

As part of an ongoing study, MC patients completed a baseline visit prior to initiating MC and evaluations following 3, 6, and 12 months of treatment. At each visit, patients completed a neurocognitive battery assessing executive function, verbal learning/memory, and clinical scales assessing mood, anxiety, and sleep. Exposure to delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) was also quantified.

RESULTS

Relative to baseline, MC patients demonstrated significant improvements on measures of executive function and clinical state over the course of 12 months; verbal learning/memory performance generally remained stable. Improved cognitive performance was not correlated with MC use; however, clinical improvement was associated with higher CBD use. Analyses suggest cognitive improvements were associated with clinical improvement.

CONCLUSIONS

Study results extend previous pilot findings, indicating that MC patients may exhibit enhanced rather than impaired executive function over time. Future studies should examine distinctions between recreational and MC use to identify potential mechanisms related to cognitive changes and the role of clinical improvement.

Demographic and policy-based differences in behaviors and attitudes towards driving after marijuana use: an analysis of the 2013-2017 Traffic Safety Culture Index

OBJECTIVE

Marijuana policies in the United States have become more permissive, motivating research on demographic and policy-based differences in behaviors and attitudes towards driving after marijuana use. The Traffic Safety Culture Index is an annual survey with national scope and multiple measures relevant to driving after marijuana use. We tabulated responses to questions about driving after marijuana use from the Traffic Safety Culture Index based on demographic factors, recreational and medical marijuana policies, and per-se marijuana laws.

RESULTS

Male, younger, lower-income, and lower-education respondents self-reported driving after marijuana use more than their demographic counterparts, more often reported such behavior to be personally acceptable, and exhibited lower support per-se laws. Drivers in states that legalized medical marijuana self-reported driving after marijuana use slightly more than drivers in states where both medical and recreational were illegal. Support for per-se laws was higher among those in states that legalized recreational marijuana and in states with per-se laws. Demographic differences in our outcomes were consistent and cohesive. On the other hand, we found no predominant pattern suggesting that those in states with liberal marijuana policies were more tolerant of driving after marijuana use.

The why behind the high: determinants of neurocognition during acute cannabis exposure

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis.

"Light cannabis" consumption in a sample of young adults: Preliminary pharmacokinetic data and psychomotor impairment evaluation

INTRODUCTION

In 2019, the Italian Supreme Court established that hemp cannot be commercialized for human use, when the "psychotropic effect" of the product or its "offensiveness" can be demonstrated. The aim of the present study is to assess Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) blood concentrations after smoking cannabis with a low percentage of Δ9-THC, also referred as "light cannabis", and its effects on young adults' vigilance, cognitive and motor skills.

MATERIALS AND METHODS

Eighteen young adults consumed three light cannabis cigarettes containing 400 mg of inflorescences each, with a percentage of 0.41% of Δ9-THC and of 12.41% of CBD. Blood samples were collected before the experiment (t0), after each light cannabis cigarette (t1→t3), 60 (t4) and 120 (t5) minutes after the beginning of the experiment. Five performance tasks and a subjective scale were employed for measuring cognitive and psychomotor performances the day before the experiment (TT0) and after the third cigarette (TT1).

RESULTS

Mean (SD) concentrations (ng/ml) were 1.0 (0.8) in t1, 1.2 (0.9) in t2, 1.0 (0.8) in t3, 0.6 (0.4) in t4 and 0.3 (0.3) in t5 for Δ9-THC; 10.5 (10.3) in t1, 10.3 (13.2) in t2, 15.1 (14.8) in t3, 9.9 (9.2) in t4 and 5.7 (5.7) in t5 for CBD. No significant differences were observed between TT0 and TT1 for all performed psychomotor performance task. None of the subjects declared to feel "high" after the experiment.

DISCUSSION

All study participants reported that a higher number of cigarettes, corresponding in this study to 1200 mg of herbal product, could hardly be consumed by smoking in a recreational setting. Δ9-THC and CBD concentrations showed a high inter-subject variability, and the average concentrations were lower than those previously reported. Toxicological results showed a decrease of Δ9-THC and CBD after the third light cannabis cigarette, and a Δ9-THC /CBD ratio always<1 was observed. The lack of impairment observed in our participants can be interpreted as a consequence of the very low concentrations detectable in the blood.

Simultaneous quantification of 18 different phytocannabinoids in serum using a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method

The potential therapeutic effects of various phytocannabinoids and the availability of multiple cannabis-based medicines make it desirable to have an analytical method that simultaneously quantifies a wide range of cannabinoids in blood, beyond delta-9-tetrahydrocannabinol and its metabolites. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of 18 phytocannabinoids and cannabinoid metabolites in serum was developed and validated. The method enables simultaneous detection of delta-9-tetrahydrocannabinol, cannabidiol, cannabinol, cannabigerol, cannabichromene, cannabicyclol, tetrahydrocannabivarin and cannabidivarin and their acidic precursors tetrahydocannabinolic acid A, cannabidiolic acid, cannabinolic acid, cannabigerolic acid, cannabichromenic acid, cannabicyclolic acid, tetrahydrocannabivarinic acid and cannabidivarinic acid as well as the delta-9-tetrahydrocannabinol metabolites 11-hydroxy-tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol. Limits of detection ranged from 0.0004 to 1 ng/mL and limits of quantification ranged from 0.004 to 2 ng/mL. Calibration curves of all analytes were linear over the whole calibration range. Recovery rates of 52 to 86% were obtained for all analytes except for cannabicyclol (49%), 11-nor-9-carboxy-tetrahydrocannabinol (46%), cannabichromenic acid (44%) and cannabidivarinic acid (36%). Acceptable bias and precision data were demonstrated for all analytes. The method was successfully applied to 55 forensic serum samples, obtained from the Institute of Legal Medicine Mainz.

Duration of Neurocognitive Impairment With Medical Cannabis Use: A Scoping Review

While the recreational use of cannabis has well-established dose-dependent effects on neurocognitive and psychomotor functioning, there is little consensus on the degree and duration of impairment typically seen with medical marijuana use. Compared to recreational cannabis users, medical cannabis patients have distinct characteristics that may modify the presence and extent of impairment. The goal of this review was to determine the duration of acute neurocognitive impairment associated with medical cannabis use, and to identify differences between medical cannabis patients and recreational users. These findings are used to gain insight on how medical professionals can best advise medical cannabis patients with regards to automobile driving or safety-sensitive tasks at work. A systematic electronic search for English language randomized controlled trials (RCTs), clinical trials and systematic reviews (in order to capture any potentially missed RCTs) between 2000 and 2019 was conducted through Ovid MEDLINE and EMBASE electronic databases using MeSH terms. Articles were limited to medical cannabis patients using cannabis for chronic non-cancer pain or spasticity. After screening titles and abstracts, 37 relevant studies were subjected to full-text review. Overall, seven controlled trials met the inclusion/exclusion criteria and were included in the qualitative synthesis: six RCTs and one observational clinical trial. Neurocognitive testing varied significantly between all studies, including the specific tests administered and the timing of assessments post-cannabis consumption. In general, cognitive performance declined mostly in a THC dose-dependent manner, with steady resolution of impairment in the hours following THC administration. Doses of THC were lower than those typically reported in recreational cannabis studies. In all the studies, there was no difference between any of the THC groups and placebo on any neurocognitive measure after 4 h of recovery. Variability in the dose-dependent relationship raises the consideration that there are other important factors contributing to the duration of neurocognitive impairment besides the dose of THC ingested. These modifiable and non-modifiable factors are individually discussed.

Cannabis and crash risk among older drivers

The purpose of this research was to reanalyze data collected from the National Highway Traffic Safety Administration's Drug and Alcohol Crash Risk Study to investigate whether driving under the influence of cannabis (THC-positive) was associated with elevated crash risk for younger and older drivers. The data came from a case-control relative risk study collected from Virginia Beach, VA, over a 20-month period. Data collectors gathered driver information from the scene of vehicle crashes and, in some cases, from hospitals. Non-crash controls were sampled from the same locations, days, and times as crashes. Key data items included driver demographics and oral fluid and blood samples, which were assayed for licit and illicit drugs. We found no overall association between cannabis use and risk of crash involvement. However, when age and age² were allowed to interact with THC, significant interaction effects emerged. THC was associated with increased risk of crash involvement for older drivers. Difference between THC-positive and sober drivers emerged as significant at age 64. The research underscores the value of examining drugged driving in the context of driver age. Age-related declines in neurocognitive and psychomotor functioning were not measured but might be important in explaining the results.

Intoxication by a synthetic cannabinoid (JWH-018) causes cognitive and psychomotor impairment in recreational cannabis users

BACKGROUND

Smoking mixtures containing synthetic cannabinoids (SCs) have become very popular over the last years but pose a serious risk for public health. Limited knowledge is, however, available regarding the acute effects of SCs on cognition and psychomotor performance. Earlier we demonstrated signs of impairment in healthy volunteers after administering one of the first SCs, JWH-018, even though subjective intoxication was low. In the current study, we aimed to investigate the acute effects of JWH-018 on several cognitive and psychomotor tasks in participants who are demonstrating representative levels of acute intoxication.

METHODS

24 healthy cannabis-experienced participants took part in this placebo-controlled, cross-over study. Participants inhaled the vapor of 75 μg JWH-018/kg body weight and were given a booster dose if needed to induce a minimum level of subjective high. They were subsequently monitored for 4 h, during which psychomotor and cognitive performance, vital signs, and subjective experience were measured, and serum concentrations were determined.

RESULTS

Maximum subjective high (average 64%) was reached 30 min after administration of JWH-018, while the maximum blood concentration was shown after 5 min (8 ng/mL). JWH-018 impaired motor coordination (CTT), attention (DAT and SST), memory (SMT), it lowered speed-accuracy efficiency (MFFT) and slowed down response speed (DAT).

CONCLUSION

In accordance with our previous studies, we demonstrated acute psychomotor and cognitive effects of a relatively low dose of JWH-018.

Increased Likelihood of Falling in Older Cannabis Users vs. Non-Users

Cannabis is one of the most common drugs in the United States and is the third most prevalent substance consumed by adults aged 50 years and older. Normal aging is associated with physiological changes that make older adults vulnerable to impaired function and geriatric conditions (e.g., falls, cognitive impairment). However, the impact of medical cannabis use on fall risk in older adults remains unexplored. The purpose of this study was to investigate if cannabis use in older adults influences fall risk, cognitive function, and motor function. It was hypothesized that older chronic cannabis users would perform worse than non-users on gait, balance, and cognitive tests. Sixteen older adults, split into cannabis Users and age- and sex-matched Non-Users groups (n = 8/group), participated in the study. The results indicate a higher fall risk, worse one leg standing balance performance, and slower gait speed in Users vs. Non-Users. No significant differences in cognitive function were found. Thus, chronic cannabis use was purported to exacerbate the poorer balance control and slower gait velocity associated with normal aging. Future mechanistic (e.g., neuroimaging) investigations of the short- and long-term effects of using a variety of cannabis products (e.g., THC/CBD ratios, routes of administration) on cognitive function, motor function, and fall incidence in older adults are suggested.

Acute effects of partial CB1 receptor agonists on cognition - A meta-analysis of human studies

BACKGROUND

Impairment in cognition is frequently associated with acute cannabis consumption. However, some questions remain unanswered as to which deficits are most prominent and which demographic groups are most vulnerable.

METHODS

A literature search yielded 52 experimental studies of acute administration of partial CB₁ receptor agonists (i.e. cannabis, THC, and nabilone) that assessed cognitive dysfunction in 1580 healthy volunteers. Effect size estimates were calculated using the Comprehensive Meta-Analysis for the following six cognitive domains: attention, executive functions, impulsivity, speed of processing, verbal learning/memory, and working memory.

RESULTS

There were small-to-moderate impairments across all cognitive domains. Deficits in verbal learning/memory and working memory were more prominent, whereas attention and impulsivity were the least affected. Meta-regression analysis revealed that the greater the male ratio is in a sample, the greater the negative effect of cannabinoids on speed of processing and impulsivity. Analysis of route of administration showed that the deficits in speed of processing were smaller in the oral, relative to smoking, vaping, and intravenous administration studies. A publication bias was observed.

DISCUSSION

Verbal learning/memory and working memory are most prominently affected by acute administration of partial CB₁ receptor agonists. The results are consistent with the residual cognitive effects that have been documented among chronic cannabis users.

The Behavioral Sequelae of Cannabis Use in Healthy People: A Systematic Review

Background: Cannabis is known to have a broad range of effects on behavior, including experiencing a "high" and tranquility/relaxation. However, there are several adverse behavioral sequalae that can arise from cannabis use, depending on frequency of use, potency (e.g., THC content), age of onset, and cumulative exposure. This systematic review examined evidence for cannabis-related adverse behavioral sequalae in otherwise healthy human subjects. Methods: Following PRISMA guidelines, we conducted a systematic review of cross-sectional and longitudinal studies from 1990 to 2020 that identified cannabis-related adverse behavioral outcomes in subjects without psychiatric and medical co-morbidities from PubMed and PsychInfo searches. Key search terms included "cannabis" OR "tetrahydrocannabinol" OR "cannabidiol" OR "marijuana" AND "anxiety" OR "depression" OR "psychosis" OR "schizophrenia" "OR "IQ" OR "memory" OR "attention" OR "impulsivity" OR "cognition" OR "education" OR "occupation". Results: Our search detected a total of 2,870 studies, from which we extracted 124 relevant studies from the literature on cannabis effects in the non-clinical population. Effects of cannabis on several behavioral sequelae including cognition, motivation, impulsivity, mood, anxiety, psychosis intelligence, and psychosocial functioning were identified. The preponderance of the evidence suggests that frequency of cannabis use, THC (but not CBD) content, age of onset, and cumulative cannabis exposure can all contribute to these adverse outcomes in individuals without a pre-existing medical condition or psychiatric disorder. The strongest evidence for the negative effects of cannabis are for psychosis and psychosocial functioning. Conclusions: Although more research is needed to determine risk factors for development of adverse behavioral sequelae of cannabis use, these findings underline the importance of understanding vulnerability to the adverse effects of cannabis, which has implications for prevention and treatment of problematic cannabis use.

The Role of Gamma Oscillations in the Pathophysiology of Substance Use Disorders

Substance use disorders (SUDs) are a major public health problem—with over 200 million people reporting drug use in 2016. Electroencephalography (EEG) is a powerful tool that can provide insights into the impact of SUDs on cognition. Specifically, modulated gamma activity may provide an index of the pathophysiology of SUDs. Thus, the purpose of this review was to investigate the impact of alcohol, tobacco, cannabis, cocaine, and amphetamine on gamma activity, among pre-clinical and clinical populations during acute and chronic exposure and withdrawal states. We searched multiple databases for key terms related to SUDs, EEG, and gamma and ensured rigorous methods by using a standardized review reporting tool. We included 30 studies in this review and found that all substances were associated with modulation of gamma activity, across states and in both preclinical and clinical populations. Gamma oscillations appeared to be differentially modulated in clinical versus preclinical populations and had the most complex relationship with alcohol, indicating that it may act differently than other substances. The findings of this review offer insights into the pathophysiology of SUDs, providing a potential window into novel treatments for SUDs via modulation of gamma activity.

Sex Differences in the Association between Household Income and Children's Executive Function

The study aimed to investigate sex differences in the boosting effects of household income on children's executive function in the US. This is a cross-sectional study using data from Wave 1 of the Adolescent Brain Cognitive Development (ABCD) study. Wave 1 ABCD included 8608 American children between ages 9 and 10 years old. The independent variable was household income. The primary outcome was executive function measured by the stop-signal task. Overall, high household income was associated with higher levels of executive function in the children. Sex showed a statistically significant interaction with household income on children's executive function, indicating a stronger effect of high household income for female compared to male children. Household income is a more salient determinant of executive function for female compared to male American children. Low-income female children remain at the highest risk regarding poor executive function.

Impulsive Sports Betting: The Effects of Food or Substance Consumption

The present study aimed to explore how food or substance consumption (e.g., experiencing hunger, or having consumed alcohol or recreational drugs) could shape consumer impulsive spending on sports betting products. Based on a large online sample of Australian sports bettors, we found that participants with higher hunger level, or having consumed more alcohol or recreational drugs, tended to have increased impulsive bet size. These impulsiveness effects had both direct and indirect effect components. The significant direct effects confirmed that positive relationships directly existed between hunger, alcohol consumption, or recreational drug consumption and impulsive bet size, even when all potential mediators and covariates were statistically controlled. Moreover, results regarding specific indirect effects demonstrated that hunger, alcohol consumption, or recreational drug consumption was also indirectly linked with impulsive bet size, via their relationships with both promotional and financial influences, rather than social influences. Furthermore, participants' Problem Gambling Severity Index score was positively associated with their impulsive bet size. These findings support and complement the literature on impulsivity as well as the research on strategies for staying in control of gambling, and have implications for consumers, regulators, and treatment/help providers.

Sweetening the pot: Exploring differences between frequent gamblers who do and do not gamble under the influence of cannabis

The legalization of recreational cannabis for adults is becoming more common across the United States of America, as well as other counties around the world. Previous research has documented shared risk factors between cannabis use and gambling. Experimental studies have shown cognitive effects of cannabis that might influence gambling behavior. The current study explored demographics, gambling behaviors, and mental health differences based on the degree to which individuals use cannabis while they gamble. Individuals (N = 805) who gambled at least weekly completed an online survey. Thirty percent reported gambling under the influence of cannabis. Of these individuals, 41% reported using cannabis 25% of the time that they gambled, 31% reported being under the influence 50% of the time when gambling, 16% were under the influence 75% of the time when gambling, and 13% reported always or almost always gambling under the influence of cannabis. Those who reported gambling while under the influence of cannabis were more likely to be younger, non-white and non-heterosexual. They also reported higher levels of psychological distress, were more likely to have had a diagnosis of ADHD and a history of treatment for gambling, substance use, or other kinds of mental health concerns. Individuals who used cannabis while gambling also reported gambling more frequently than those who did not. This study provides one of the first explorations into who uses cannabis while gambling. Future experimental studies are required to investigate the direct effects of cannabis on gambling behaviors.

Vape shop owners'/managers' attitudes about CBD, THC, and marijuana legal markets

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Vape shop owners/managers perceive minimal risk and therapeutic benefits of CBD.

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They held diverse perspectives regarding marijuana retail and its potential impact.

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Some owners/merchants do not consider the CBD or THC markets in their business.

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Others indicated high levels of enthusiasm for the growing retail marijuana market.

Over the past decade in the US there have been marked pivotal changes in the policy and retail environment regarding cannabinoids, particularly cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). Many vape shops may carry products relevant to these two markets. This study interviewed vape shop owners/managers to assess their perceptions of consumer interests/behaviors regarding CBD and THC and of the impact of legalized marijuana retail on vape shops. The current study involved phone-based semi-structured interviews of 45 vape shop owners/managers in six metropolitan statistical areas (MSAs; Atlanta, Boston, Minneapolis, Oklahoma City, San Diego, and Seattle) during Summer 2018. Overall, 82.2% of participants were male, 77.8% were non-Hispanic White, 64.4% were managers, 8.9% reported past 30-day smoking, and 95.6% reported past 30-day vaping. Overall, 44.4% sold e-liquids containing CBD. Vape shop owners/managers indicated minimal perceived risk and some beliefs in therapeutic benefits of CBD products; however, there was a broader range of perspectives regarding marijuana retail and selling marijuana for recreational use. Some chose to distance themselves from marijuana products, their use, and the possibility of entering marijuana retail if it were to evolve in their state, while some indicated high levels of enthusiasm for the growing retail marijuana market. Future research should examine how vape shops and other retailers of CBD and marijuana communicate with consumers about products and modes of using such products, as well as how various industry sectors (e.g., vape shops) adapt or evolve with increasing regulation of nicotine and increasing legalization of marijuana retail.