Cannabis and Driving

Evaluation of Cannabis Per Se Laws: A Semi-Mechanistic Pharmacometrics Model for Quantitative Characterization of THC and Metabolites in Oral Users

Recreational cannabis use has increased notably in the United States in the past decade, with a recent surge in oral consumption. This trend has raised concerns about driving under the influence. Current cannabis-impaired driving laws lack standardization, with some states implementing blood Δ9-tetrahydrocannabinol (THC) per se limits (1, 2, and 5 ng/mL). However, these limits have been criticized for their inaccuracy and unreliability, highlighting the need for legal refinement. Addressing this issue requires understanding the complex pharmacokinetics (PK) and pharmacodynamics (PD) of THC, cannabis's primary psychoactive component, which can be characterized using a population PK model. However, existing PK models mainly focus on inhalation data and do not account for the growing number of oral cannabis users. To bridge this gap, a semi-mechanistic population PK model was developed using data from 10 published studies following intravenous or oral administration of cannabis to characterize THC and its metabolites in oral users. Simulated THC plasma concentrations for doses from 2.5 mg to 100 mg in frequent and occasional users were used to evaluate the effectiveness of existing per se limits. Results showed that the 1 ng/mL limit was least effective due to a high risk of false positives, while the 2 and 5 ng/mL limits remain inconclusive due to limited PD data linking blood THC levels to impairment. These findings suggest that the existing per se laws may not fully address the complexity of cannabis impairment, underscoring the need for further research and refinement of cannabis-impaired driving laws.

Association of Marijuana Use With Psychological Distress Among Adults in United States

PurposeDetermine the association of marijuana use with serious psychological distress (SPD) among adults aged 18 years or older using a large, nationally representative sample of US households.DesignCross-sectional analysis.SettingData from the National Survey on Drug Use and Health, 2021.Subjects47,247 respondents representing 253.7 million adults (age>18 years) in the US.MeasuresMarijuana use was categorized as (1) None, (2) within the past month, (3) within 1 year, and (4) more than a year ago from the interview time. SPD was measured with the Kessler-6 distress scale.AnalysisBivariable and multivariable logistic regression analyses accounting for complex survey designs were conducted.ResultsAmong adults in the US, 50.9% never used marijuana, 13.7%, 6.0%, and 29.4% reported marijuana use in the past month, in the past year, and more than a year ago, respectively. Individuals using marijuana within the past month, within a year, and more than a year ago reported higher past month SPD (15.3%, 13.5%, and 6.8%, respectively) than never-users (4.9%). Adjusted logistic regression analysis revealed that marijuana use in the past month, past year (1-12 months), and over a year ago is associated with higher SPD (AOR [95% CI] = 2.06 [1.72, 2.45]; 1.82 [1.50, 2.21]; 1.53 [1.26, 1.87], respectively) compared to no marijuana use.ConclusionAdults who used marijuana more recently were more likely to report SPD.

A randomized, placebo-controlled, double-blind, pilot study of cannabis-related driving impairment assessed by driving simulator and self-report

AIMS

In the context of increasing cannabis use, understanding how cannabis affects specific driving behaviors is crucial in mitigating risks and ensuring road safety.

DESIGN AND SETTING

The current study included 38 adults aged 18-40 years, administered a single 0.5 g acute dose of vaporized cannabis (5.9% Tetrahydrocannabinol (THC), 13% THC or placebo) in a randomized, within-subject, double-blind, counterbalanced design. Throughout each of the three, 8-h assessment days, at 4 time points, participants underwent simulated driving tests, including lane-keeping, car following, and overtaking tasks, capturing 19 behavioral metrics. An SPSS linear mixed model assessed the main effects of dose, time, and dose × time.

FINDINGS

During lane-keeping, participants exhibited reduced steering reversal rates up to 5.5 h following 13% THC and 3.5 h for 5.9%. For car following, participants showed reduced pedal peak-to-peak deviation and reversal rates, persisting for 1-3 h post-dose (only at 13% THC). During overtaking, following 13% THC, subjects demonstrated a shorter median gap to passed cars, lower time-to-potential collision, and more time in the oncoming lane. Drug effects on driving metrics improved gradually, to varying degrees over time. Approximately 66% of participants reported willingness to drive, despite subjective awareness of being impaired and objectively worse driving performance.

CONCLUSIONS

Our study reveals for the first time long-lasting cannabis-induced impairments across multiple driving behaviors, that extend beyond the typical 3-h window explored in most previous research. The observed discrepancy between participants' willingness to drive and their actual impairment highlights an important public safety concern. In addition, the lack of correlation between cannabinoid metabolite concentrations and driving performance challenges the reliability of blood THC levels as impairment indicators, emphasizing the need for a multifaceted approach to assessing cannabis-impaired driving risk.

Cannabis, cannabinoids and health: a review of evidence on risks and medical benefits

The legalization of cannabis for medical and recreational purposes has progressed internationally. Cannabis and cannabinoids are advocated for a plethora of medical indications. An increasing number of medical and nonmedical users regularly consume large doses of delta-9-Tetrahydrocannabinol (THC), the main active component of cannabis. Aim: to summarize the evidence on (1) risks of recreational cannabis use and (2) effectiveness and safety of medicinal cannabis. Findings on recreational use: Cannabis is mostly used to experience its acute rewarding effects. Regular use of high THC products can produce addiction (cannabis use disorder or CUD). Acute consumption of high THC doses (including unintentionally) can cause time-limited mental, gastrointestinal, and cardiovascular problems and motor vehicle accidents. Chronic patterns of cannabis use have been associated with multiple adverse outcomes that are of particular concern among adolescents and young adults, such as, disrupted learning, impaired cognitive performance, reduced educational attainment and an increased risk of CUD, psychosis/schizophrenia, mood and anxiety disorders and suicidal behaviors. There is debate about the extent to which cannabis use is a cause of these adverse outcomes. Physical health risks (e.g., respiratory and cardiovascular, prematurity and restricted fetal growth, hyperemesis syndrome among others) have also been linked with repeated consumption of cannabis with a high THC content. Findings on medical cannabis use: Herbal cannabis, medicines from extracted or synthetized cannabinoids-often used as adjuvants to standard medicines-may produce small to modest benefits. This is primarily the case in treating chronic pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and refractory epilepsy (in the case of cannabidiol, CBD). The evidence is inconclusive on their value in treating mental disorders and other medical conditions. Safety: Cannabis-based medicine is generally well tolerated. There is a risk of mild to moderate adverse effects and CUD.

Frequency is not enough: Characterizing heterogenous patterns of cannabis use intensity among reservation-area American Indian youth

BACKGROUND

Reservation-area American Indian (AI) youth use cannabis at significantly higher rates than their national counterparts. This discrepancy is concerning, as cannabis use-particularly heavy use-can negatively impact adolescents' health. Studies primarily use frequency to classify cannabis use intensity; however, frequency alone may not fully capture heterogenous patterns of use. This study aimed to classify AI adolescents' cannabis use based on multiple intensity indicators, and to investigate interclass differences in problematic characteristics and outcomes of use.

METHODS

Participants were 799 reservation-area AI youth (7-12th grade) reporting 12-month cannabis use. Latent Class Analysis (LCA) was used to distinguish cannabis use intensity patterns based on frequency, typical intoxication levels and duration. Auxiliary tests using R3STEP and BCH 3-step procedures were used to assess class predictors (age, initiation age, sex) and interclass differences in simultaneous drug use, stress-motivated use, problems quitting and cannabis-related consequences.

RESULTS

Four classes emerged: Light Use (LU; 19 %), Occasional Intoxication (OI; 32 %), Mid-frequency Use(MU; 28 %), and Heavy Use (HU; 21 %). Age and initiation age correlated with membership odds in a heavier use class. Interclass differences in problematic characteristics and outcomes occurred between all classes, particularly for stress-motivated use and cannabis-related consequences-with HU reporting the most problematic characteristics and negative outcomes.

CONCLUSION

These findings suggest that accounting for multiple dimensions of usage intensity may be important in studies examining cannabis use and related problems among AI adolescents. Tailoring intervention programming to address complex cannabis use patterns, with particular focus on stress-coping skills and harm reduction, can ensure AI youth most at risk for cannabis problems gain maximal benefit from prevention efforts.

The Impact of Intoxication on the Prognosis of High-Speed Motor Vehicle Accidents: A Tertiary Care Center Experience

Introduction

Several studies suggest a causal link between psychoactive agents and motor vehicle accidents (MVA). This study aimed to evaluate the impact of substance abuse and alcohol intoxication on the prognosis of high-speed MVA victims.

Methods

This is a single-center retrospective cross-sectional study involving adult multiple trauma cases who were admitted to the emergency department for high-speed MVA and underwent toxicological screening. The cohort was conducted based on two main outcomes; the survival status and the neurological outcomes.

Results

894 patients with the mean age of 27.8 ± 9.24 (range:18-37) years were studied (97.9% male). The most common indicators of severity were car rollover and ejection from the car. 296 of the patients had severe traumatic brain injury (TBI). 622 of the patients had a positive toxicological screening, with benzodiazepines (51.2%) and alcohol (26.6%) being the most commonly abused substances. The mortality rate was 5.8% and 12.1% of the patients had unfavorable neurological outcomes upon discharge. On multivariate logistic regression, predictors of mortality among high-speed MVA victims were report of a death at the scene (adjusted odds ratio (aOR): 2.529; 95% confidence interval (CI): 1.026-6.232; p = 0.044), severe TBI, the presence of dilated pupils (aOR: 11.074; 95% CI: 1.293-94.812; p = 0.028), hypotension (aOR: 0.456; 95% CI: 0.227-0.916; p = 0.027), and hypoxia (aOR: 2.95; 95% CI: 1.46-5.95; p = 0.003). Predictors of unfavorable neurological outcomes were report of a death at the scene (aOR: 3.133; 95% CI: 1.445-6.791; p = 0.004), positive toxicology screening (aOR: 3.30; 95% CI:1.68-10.204; p = 0.038), severe TBI, the presence of hypoxia (aOR: 2.96; 95% CI:1.645-5.319; p = 0.000), hypotension (aOR: 0.437; 95% CI: 0.252-0.758; p = 0.003), and bleeding (aOR: 0.287; 95% CI: 0.164-0.501; p < 0.001).

Conclusion

A concerning proportion of high-speed MVA victims had a positive toxicology screening. Although intoxication did not increase mortality of high-speed MVAs, it was a significant predictor of unfavorable neurological outcomes of survivors.

Cannabis in combat sports: position statement of the Association of Ringside Physicians

and ARP Position Statement: Based on the available body of scientific evidence and with the goals of promoting safety of combat sports athletes and striving for the advancement of clean sport, the Association of Ringside Physicians recommends the following regarding cannabis:• Use of marijuana or synthetic cannabinoids by combat sports athletes is discouraged due to unproven benefits and many known adverse effects. Acute use can impair cognition and complex motor function, which likely leads to reduced performance in combat sports. Chronic use can increase risk for heart and lung disease, several cancers, schizophrenia, and can reduce testosterone in men and impair fertility. Benefits from cannabis in most contexts, including athletic performance, have not been proven.• Use of topical purified CBD is neither encouraged nor discouraged.• Since acute cannabis intoxication can impair complex cognitive and motor function, any athlete suspected of acute intoxication at the time of competition - based on clinical judgment - should be banned from that competition.• Wide-scale regulation of cannabis based on quantitative testing has limited usefulness in combat sports, for the following reasons:∘ Cannabis is not ergogenic and is likely ergolytic.∘ Concentrations in body fluids correlate poorly with clinical effects and timing of use.∘ Access to testing resources varies widely across sporting organizations.

Intoxication due to Δ9-tetrahydrocannabinol is characterized by disrupted prefrontal cortex activity

Neural states of impairment from intoxicating substances, including cannabis, are poorly understood. Cannabinoid 1 receptors, the main target of Δ9-tetrahydrocannabinol (THC), the primary intoxicating cannabinoid in cannabis, are densely localized within prefrontal cortex; therefore, prefrontal brain regions are key locations to examine brain changes that characterize acute intoxication. We conducted a double-blind, randomized, cross-over study in adults, aged 18-55 years, who use cannabis regularly, to determine the effects of acute intoxication on prefrontal cortex resting-state measures, assessed with portable functional near-infrared spectroscopy. Participants received oral THC (10-80 mg, individually dosed to overcome tolerance and achieve acute intoxication) and identical placebo, randomized for order; 185 adults were randomized and 128 completed both study days and had usable data. THC was associated with expected increases in subjective intoxication ratings (ES = 35.30, p < 0.001) and heart rate (ES = 11.15, p = 0.001). THC was associated with decreased correlations and anticorrelations in static resting-state functional connectivity within the prefrontal cortex relative to placebo, with weakest correlations and anticorrelations among those who reported greater severity of intoxication (RSFC between medial PFC-ventromedial PFC and DEQ scores, r = 0.32, p < 0.001; RSFC between bilateral mPFC and DEQ scores, r = -0.28, p = 0.001). Relative to placebo, THC was associated with increased variability (or reduced stability) in dynamic resting-state functional connectivity of the prefrontal cortex at p = 0.001, consistent across a range of window sizes. Finally, using frequency power spectrum analyses, we observed that relative to placebo, THC was associated with widespread reduced spectral power within the prefrontal cortex across the 0.073-0.1 Hz frequency range at p < 0.039. These neural features suggest a disruptive influence of THC on the neural dynamics of the prefrontal cortex and may underlie cognitive impairing effects of THC that are detectable with portable imaging. This study is registered in Clinicaltrials.gov (NCT03655717).

[Perception of cannabis use in the adolescent population: metasynthesis of qualitative studies]

OBJECTIVE

To assess the perceptions and beliefs of adolescents about cannabis consumption, studying the incentive and disincentive factors for consumption.

METHOD

A systematic review of the literature was carried out following the PRISMA guidelines. MedLine, Embase, APA PsycInfo, Cochrane and Web of Science were searched using controlled vocabulary and free terms. We included qualitative studies published between 2000 and 2024 that assessed the perceptions of adolescents aged 10 to 19 years on the use, effects, risks of using cannabis or cannabis with other legal drugs. The quality of the studies was assessed using the CASP tool.

RESULTS

Of the 3665 articles identified in the initial search, 22 complied with elegibility criteria. Data extraction yielded a series of three lines of argument linked to cannabis use: reasons for use, reasons for not using and perceived effects. The most common discourse among adolescents was related to the feeling of social and emotional well-being, fewer adverse effects than drugs, and the influence of peers on consumption.

CONCLUSIONS

The review preformed reports on the reasons that adolescents allege for cannabis use and reasons for abstention with a view of the preponderance of benefits over harms. It is considered that this information may be necessary for the development of prevention programmes with the dissemination of information on the effects of consumption.

Latent Trajectories of Persistence of Cannabis Use Across Four Decades in 329 Men From the San Diego Prospective Study

OBJECTIVE

These analyses use data from a 40-year prospective study to extend information into the sixth and seventh decades of life regarding latent trajectory classes of cannabis use and predictors of those classes.

METHOD

Data from the San Diego Prospective Study were analyzed for 329 men of European and Hispanic ethnicity who had used cannabis at about age 23 at study entry (Time 1) and who were interviewed about every 5 years through about age 60 to 70. Latent classes of cannabis use trajectories were evaluated using latent class growth analyses, baseline predictors of class membership were determined, and significant predictors of each class were established using logistic regression analyses.

RESULTS

Four latent classes were identified ranging from 12.5% with cannabis use at every follow-up to 25.8% with no use after Time 1. Eight of 14 Time 1 predictors differed significantly across the trajectory classes, including five (age, marital status, religious identity, intensity of cannabis use, and sensation seeking) that significantly contributed to regression analyses when all significant predictors were considered together.

DISCUSSION

Forty-two percent of participants continued using cannabis long-term, including one in eight who used it at every follow-up. Predictors of continued use and identification of those most likely to stop required gathering information on a range of demographic, prior substance use, and personality characteristics.

CONCLUSIONS

Considering the potential enhanced dangers of cannabis use in later life, the high rate of continued use over four decades implies that clinicians should ask all older patients about recent cannabis use, especially if they had used it in their 20s.

The association between single and dual use of cannabis and alcohol and driving under the influence and riding with an impaired driver in a large sample of Canadian adolescents

OBJECTIVE

Dual use of cannabis and alcohol has increased in adolescents, but limited research has examined how it relates to impaired driving or riding with an impaired driver (IDR) compared to single substance use. This study aimed to examine the odds of alcohol- and/or cannabis-IDR among adolescents based on their use of alcohol and/or cannabis, and whether associations differed by gender and age.

METHODS

Cross-sectional survey data were used from a sample of 69,621 students attending 182 Canadian secondary schools in the 2021/22 school year. Multilevel logistic regression estimated the odds of exclusive alcohol-IDR, exclusive cannabis-IDR, and both alcohol and cannabis IDR (alcohol-cannabis-IDR). Substance use interactions with gender and age were tested.

RESULTS

Overall, 14.7% of participants reported IDR; 7.5% reported exclusive alcohol-IDR, 3.2% reported exclusive cannabis-IDR, 4.0% reported alcohol-cannabis-IDR, and 7.4% were unsure if they had experienced IDR. The prevalence of IDR varied across substance use groups, 8.0% among nonuse, 21.9% among alcohol-only use, 35.9% among cannabis-only use, and 49.6% among dual use groups. Gender diverse, older, and students with lower socioeconomic status exhibited a higher likelihood of reporting alcohol-cannabis-IDR. Dual use was significantly associated with 9.5 times higher odds of alcohol-cannabis-IDR compared to alcohol-only use, and 3.0 times higher odds compared to cannabis-only use. Dual use was also associated with an increased likelihood of either alcohol- or cannabis-IDR.

CONCLUSIONS

This study highlights that all students, regardless of substance use, are at risk of IDR, but students engaged in dual use of alcohol and cannabis face an elevated risk compared to both peers who do not use substances and those who use only a single substance. These findings emphasize the importance of targeted interventions that address the risks associated with IDR.

Delays in blood collection and drug toxicology results among crash-involved drivers arrested for impaired driving

OBJECTIVE

The concentration of drugs in a driver's system can change between an impaired driving arrest or crash and the collection of a biological specimen for drug testing. Accordingly, delays in specimen collection can result in the loss of critical information that has the potential to affect impaired driving prosecution. The objectives of the study were: (1) to identify factors that influence the time between impaired-driving violations and specimen collections (time-to-collection) among crash-involved drivers, and (2) to consider how such delays affect measured concentrations of drugs, particularly with respect to common drug per se limits.

METHOD

Study data included blood toxicology results and crash-related information from 8,923 drivers who were involved in crashes and arrested for impaired driving in Wisconsin between 2019 and 2021. Analyses examined how crash timing and severity influenced time-to-collection and the effects of delays in specimen collection on blood alcohol concentrations (BACs) and blood delta-9-tetrahydrocannabinol (THC) concentrations.

RESULTS

The mean time-to-collection for the entire sample was 1.80 h. Crash severity had a significant effect on time-to-collection with crashes involving a fatality having the longest duration ( M = 2.35 h) followed by injury crashes ( M = 2.06 h) and noninjury crashes ( M = 1.69 h). Time of day also affected time-to-collection; late night and early morning hours were associated with shorter durations. Both BAC (r = -0.11) and blood THC concentrations (r = -0.16) were significantly negatively correlated with time-to-collection.

CONCLUSIONS

Crash severity and the time of day at which a crash occurs can result in delays in the collection of blood specimens after impaired driving arrests. Because drugs often continue to be metabolized and eliminated between arrest and biological specimen collection, measured concentrations may not represent the concentrations of drugs that were present at the time of driving. This has the potential to affect drug-impaired driving prosecution, particularly in jurisdictions whose laws specify per se impairment thresholds.

Driving Under the Influence of Alcohol, Cannabis, and Delta-8 THC: Perceived Likelihood, Risk Perceptions, and Behaviors

Driving under the influence (DUI) of alcohol or cannabis poses public health risks. Little is known about DUI of Delta-8 THC, a newer cannabis product. Using 2022 survey data among 189 U.S. adults ages 18-25 (58.73% male, 59.26% non-Hispanic White), multivariable logistic regression examined substance-specific (alcohol, cannabis, Delta-8) DUI perceived likelihood and risk in relation to past-year DUI among those with past-year use of each. Overall, 72.49% reported past-year alcohol use, 50.53% cannabis, and 22.46% Delta-8. Among those reporting past-year use of each respective substance, 33.58% reported DUI of alcohol, 32.63% cannabis, and 57.14% Delta-8. On average, participants had the same DUI perceived likelihood ("somewhat unlikely") across substances and perceived alcohol DUI as riskiest. Higher alcohol DUI perceived likelihood and lower perceived risk were associated with alcohol-related DUI. Greater cannabis-related perceived likelihood (but not risk) was associated with cannabis-related DUI. Neither Delta-8 DUI perceived likelihood nor risk were associated with Delta-8 DUI. In sum, perceived DUI likelihood for alcohol, cannabis, or Delta-8 tended to be similar. Among those with past-year use of each, the proportion of DUI was highest for Delta-8. Interventions should target DUI-related perceived likelihood and promote protective behavioral strategies that reduce substance-specific DUI risk.

Drug driving: a secondary analysis of factors associated with driving under the influence of cannabis in Jamaica

OBJECTIVES

To determine cannabis use patterns, the predictive sociodemographic correlates of driving under the influence of cannabis (DUIC) and the association between risk perception and cannabis dependence among vehicle drivers in Jamaica.

DESIGN

Secondary data analysis.

SETTING

Used the Jamaica National Drug Prevalence Survey 2016 dataset.

PARTICIPANTS

1060 vehicle drivers extracted from the population sample of 4623.

PRIMARY AND SECONDARY OUTCOME MEASURES

Analysis used Pearson's χ2 test and logistic regression. ORs and 95% CIs were recorded. A p<0.05 was considered statistically significant.

RESULTS

More than 10% of Jamaican drivers admitted to DUIC in the past year. Approximately 43.3% of drivers who currently use cannabis reported DUIC only. Evidently, 86.8% of drivers who DUIC were heavy cannabis users. Approximately 30% of drivers with moderate to high-risk perception of smoking cannabis sometimes or often were dependent on cannabis. Notwithstanding, drivers with no to low-risk perception of smoking cannabis sometimes or often were significantly likelier to be dependent (p<0.001 and p<0.001, respectively). Logistic regression highlighted male drivers (OR 4.14, 95% CI 1.59 to 14.20, p=0.009) that were 34 years and under (OR 2.97, 95% CI 1.71 to 5.29, p<0.001) and were the head of the household (OR 2.22, 95% CI 1.10 to 4.75, p=0.031) and operated a machine as part of their job (OR 1.87, 95% CI 1.09 to 3.24, p=0.023) were more likely to DUIC, while those who were married (OR 0.42, 95% CI 0.22 to 0.74, p=0.004) and had achieved a tertiary-level education (OR 0.26, 95% CI 0.06 to 0.76, p=0.031) were less likely.

CONCLUSIONS

Two in five Jamaican drivers, who currently smoke cannabis, drive under its influence, with over 85% engaging in heavy use. Public health implications necessitate policy-makers consider mobile roadside drug testing and amending drug-driving laws to meet international standards.

Impaired driving and other risky drug use and sex behaviors: a cross-sectional examination of high-risk rural women incarcerated in jail

Background: Despite women accounting for an increasing proportion of impaired drivers and higher rates of impaired driving and road fatalities in rural areas, little is known about rural women who drive impaired and their other risky behavior.Objective: The present study assessed the association between impaired driving history, risky substance use, and other drug- and sex-related risk behaviors in a sample of high-risk rural women incarcerated in jail.Methods: Four hundred women from three rural jails provided information about their impaired driving, drug use, injection drug use practices, and sex risk behaviors. Groups were stratified on whether they self-reported impaired driving in the year prior to incarceration. Impaired drivers (n = 260, M = 31.90 years old) were compared to women who did not drive impaired (n = 131, M = 34.42 years old) using MANCOVA and logistic regression analyses.Results: Impaired drivers had significantly (p < .05) higher substance use severity scores for cannabis, sedatives, and prescription opioids. Furthermore, impaired drivers were significantly (p < .05) more likely to have been the passenger of an impaired driver (78.08% vs. 53.44%), been an injection drug user (69.62% vs. 41.98%), had a casual sex partner (47.31% vs. 25.95%), and traded sex for drugs or money (31.15% vs. 15.27%) in the year prior to incarceration.Conclusions: This study found a consistent association between past year impaired driving and a range of drug- and sex-related risk behaviors in a sample of high-risk rural women incarcerated in jail. These findings highlight an opportunity to intervene in criminal justice settings to reduce multiple health risk behaviors.

Can inhaled cannabis users accurately evaluate impaired driving ability? A randomized controlled trial

Aims

To study the effect of inhaled cannabis on self-assessed predicted driving ability and its relation to reaction times and driving ability on a driving simulator.

Participants and methods

30 healthy male volunteers aged 18-34: 15 chronic (1-2 joints /day) and 15 occasional (1-2 joints/week) consumers. Self-assessed driving confidence (visual analog scale), vigilance (Karolinska), reaction time (mean reciprocal reaction time mRRT, psychomotor vigilance test), driving ability (standard deviation of lane position SDLP on a York driving simulator) and blood concentrations of delta-9-tétrahydrocannabinol (THC) were measured before and repeatedly after controlled inhalation of placebo, 10 mg or 30 mg of THC mixed with tobacco in a cigarette.

Results

Cannabis consumption (at 10 and 30 mg) led to a marked decrease in driving confidence over the first 2 h which remained below baseline at 8 h. Driving confidence was related to THC dose and to THC concentrations in the effective compartment with a low concentration of 0.11 ng/ml for the EC50 and a rapid onset of action (T1/2 37 min). Driving ability and reaction times were reduced by cannabis consumption. Driving confidence was shown to be related to driving ability and reaction times in both chronic and occasional consumers.

Conclusions

Cannabis consumption leads to a rapid reduction in driving confidence which is related to reduced ability on a driving simulator.

Clinical trial registration

ClinicalTrials.gov, identifier: NCT02061020.

Differences in Plasma Cannabidiol Concentrations in Women and Men: A Randomized, Placebo-Controlled, Crossover Study

The potential therapeutic benefits of cannabidiol (CBD) require further study. Here, we report a triple-blind (participant, investigator, and outcome assessor) placebo-controlled crossover study in which 62 hypertensive volunteers were randomly assigned to receive the recently developed DehydraTECH2.0 CBD formulation or a placebo. This is the first study to have been conducted using the DehydraTECH2.0 CBD formulation over a 12-week study duration. The new formulation's long-term effects on CBD concentrations in plasma and urine, as well as its metabolites 7-hydroxy-CBD and 7-carboxy-CBD, were analyzed. The results of the plasma concentration ratio for CBD/7-OH-CBD in the third timepoint (after 5 weeks of use) were significantly higher than in the second timepoint (after 2.5 weeks of use; p = 0.043). In the same timepoints in the urine, a significantly higher concentration of 7-COOH-CBD was observed p < 0.001. Differences in CBD concentration were found between men and women. Plasma levels of CBD were still detectable 50 days after the last consumption of the CBD preparations. Significantly higher plasma CBD concentrations occurred in females compared to males, which was potentially related to greater adipose tissue. More research is needed to optimize CBD doses to consider the differential therapeutic benefits in men and women.

Let's Match: Making Cannabis Policy Guided by Research

PURPOSE

The growth and increasing sophistication of the legal cannabis industry necessitates further scientific inquiry to establish an evidence-based policy path forward. However, policymakers must balance public demand for cannabis reform with the lack of scientific consensus on key issues. This Commentary discusses Massachusetts' statutory provisions supporting cannabis research, advances in social equity driven by data, and critical policy issues, which invite questions without clear scientific answers.

FINDINGS

Although the full breadth of inquiry needed cannot possibly be contained in a single article, this Commentary poses questions in 2 pertinent issue areas that affect adult and medical use. First, we discuss the current limitations on determining the scope and severity of cannabis-impaired driving and detecting impairment at any one point in time. Although experimental studies have found varying levels of impairment on driving ability, observational data have been inconclusive regarding the extent of traffic incidents involving cannabis impairment. A precise threshold for impairment and manner of detection must be established to develop just enforcement measures. Second, we discuss the lack of clinical standardization in medical cannabis use. In the absence of a consistent clinical framework, medical cannabis patients face undue burdens that limit access to treatment. A more well-defined clinical structure is needed to enhance use of and access to therapeutic cannabis treatment models.

IMPLICATIONS

Cannabis policy reform has gone forward at the will of voters despite the status of cannabis as a Schedule I controlled substance at the federal level, which has limited opportunities to research cannabis because it is commercially available. The implication of such limitations is realized by states leading cannabis reform, where unanswered questions present an opportunity for the scientific community to inform an evidence-based path forward in cannabis policy.

Revisiting the effect of recreational marijuana on traffic fatalities

BACKGROUND

This study examines the effect of retail recreational marijuana legalization on traffic fatalities using the most current data available and recent advancements in difference-in-difference estimation methods proposed by Callaway and Sant'Anna, (2021).

METHOD

A modified difference-in-difference (CS-DID) is used to estimate the effect of recreational marijuana legalization on traffic fatalities reported in the Fatality Analysis Reporting System (FARS). Difference-in-difference regression models are run at the state-year level, using data from 2007 through 2020, and compared to estimates using traditional two-way-fixed-effects (TWFE) models.

RESULTS

Consistent with past studies, results from conventional TWFE suggest traffic fatalities increase at a rate of 1.2 per billion vehicle miles traveled (BVMT) after retail of recreational marijuana begins. However, using the CS-DID model, we find slightly larger average total treatment effects (∼2.2 fatalities per BVMT). Moreover, the size of the effect changes across time, where cohorts "treated" earlier have substantially higher increases than those who more recently legalized.

CONCLUSION

Traffic fatalities increase by 2.2 per billion miles driven after retail legalization, which may account for as many as 1400 traffic fatalities annually. States who legalized earlier experienced larger traffic fatality increases. TWFE methods are inadequate for policy evaluation and do not capture heterogeneous effects across time.

MASCC guideline: cannabis for cancer-related pain and risk of harms and adverse events

BACKGROUND

Approximately 18% of patients with cancer use cannabis at one time as palliation or treatment for their cancer. We performed a systematic review of randomized cannabis cancer trials to establish a guideline for its use in pain and to summarize the risk of harm and adverse events when used for any indication in cancer patients.

METHODS

A systematic review of randomized trials with or without meta-analysis was carried out from MEDLINE, CCTR, Embase, and PsychINFO. The search involved randomized trials of cannabis in cancer patients. The search ended on November 12, 2021. The Jadad grading system was used for grading quality. Inclusion criteria for articles were randomized trials or systematic reviews of randomized trials of cannabinoids versus either placebo or active comparator explicitly in adult patients with cancer.

RESULTS

Thirty-four systematic reviews and randomized trials met the eligibility criteria for cancer pain. Seven were randomized trials involving patients with cancer pain. Two trials had positive primary endpoints, which could not be reproduced in similarly designed trials. High-quality systematic reviews with meta-analyses found little evidence that cannabinoids are an effective adjuvant or analgesic to cancer pain. Seven systematic reviews and randomized trials related to harms and adverse events were included. There was inconsistent evidence about the types and levels of harm patients may experience when using cannabinoids.

CONCLUSION

The MASCC panel recommends against the use of cannabinoids as an adjuvant analgesic for cancer pain and suggests that the potential risk of harm and adverse events be carefully considered for all cancer patients, particularly with treatment with a checkpoint inhibitor.

Risk of Motor Vehicle Collisions and Culpability among Older Drivers Using Cannabis: A Meta-Analysis

Limited studies have investigated the effects of cannabis use on driving among older adults, who represent the fastest growing segment of drivers globally. We conducted a systematic review and meta-analysis to evaluate the effects of delta-9-tetrahydrocannabinol (THC) exposure on risks of (1) motor vehicle collisions (MVC) and (2) culpability for MVCs among adults 50 years and older. Three reviewers screened 7022 studies identified through MEDLINE, EMBASE, CENTRAL, and PsycINFO. Odds Ratios (OR) were calculated using the Mantel-Haenszel method in Review Manager 5.4.1. Heterogeneity was assessed using I2. The National Heart, Lung, and Blood Institute tool was used to assess the quality of each study. Seven cross-sectional studies were included. Three studies evaluated culpability while four evaluated MVC. The pooled risk of MVC was not significantly different between THC-positive and THC-negative older drivers (OR, 95% CI 1.15 [0.40, 3.31]; I2 = 72%). In culpability studies, THC exposure was not significantly associated with an increased risk of being culpable for MVC among adults over the age of 50 (OR, 95% CI 1.24 [0.95, 1.61]; I2 = 0%). Inspection of funnel plots did not indicate publication bias. Our review found that THC exposure was not associated with MVC involvement nor with culpability for MVCs.

The genetic aetiology of cannabis use: from twin models to genome-wide association studies and beyond

Cannabis is among the most widely consumed psychoactive substances worldwide. Individual differences in cannabis use phenotypes can partly be explained by genetic differences. Technical and methodological advances have increased our understanding of the genetic aetiology of cannabis use. This narrative review discusses the genetic literature on cannabis use, covering twin, linkage, and candidate-gene studies, and the more recent genome-wide association studies (GWASs), as well as the interplay between genetic and environmental factors. Not only do we focus on the insights that these methods have provided on the genetic aetiology of cannabis use, but also on how they have helped to clarify the relationship between cannabis use and co-occurring traits, such as the use of other substances and mental health disorders. Twin studies have shown that cannabis use is moderately heritable, with higher heritability estimates for more severe phases of use. Linkage and candidate-gene studies have been largely unsuccessful, while GWASs so far only explain a small portion of the heritability. Dozens of genetic variants predictive of cannabis use have been identified, located in genes such as CADM2, FOXP2, and CHRNA2. Studies that applied multivariate methods (twin models, genetic correlation analysis, polygenic score analysis, genomic structural equation modelling, Mendelian randomisation) indicate that there is considerable genetic overlap between cannabis use and other traits (especially other substances and externalising disorders) and some evidence for causal relationships (most convincingly for schizophrenia). We end our review by discussing implications of these findings and suggestions for future work.

The cannabidiol and marijuana research expansion act: Promotion of scientific knowledge to prevent a national health crisis

While the use of medical and recreational cannabis is rapidly expanding under state jurisdiction, the convolution of federal regulations is obstructing research progress to the detriment of healthcare equity and the protection of vulnerable populations, such as the underaged. U.S. Senate bill S.253 is designed to accelerate the development of trusted preclinical and clinical principles based on scientific data to guide physicians in their daily practice, inform lawmakers, and thereby protect public health. This goes together with a reinforcement of the legal protection that practitioners have acquired over years of litigation with the federal government when working with their patients. S.253 supports open communication between physicians and their patients when discussing cannabis as a treatment option. The bill passed the U.S. Senate on March 24, 2022.

Funding

This work was supported by intramural funding (NYIT College of Osteopathic Medicine) to the corresponding author, Dr. Joerg R. Leheste.

Edible marijuana products and potential risks for pediatric populations

PURPOSE OF REVIEW

In recent years, an increasing number of states have legalized marijuana, also known as cannabis, for recreational use. As marijuana becomes more accessible, adolescent use and accidental pediatric exposures are likely to become broad public health concerns. Edible marijuana products, which are consumable foods or beverages that contain cannabis extract, are particularly enticing to youth, as they come in appealing forms such as candies, cookies, and drinks. The purpose of this review is to provide pediatricians with an overview of the different types and potential dangers associated with edible marijuana products.

RECENT FINDINGS

Edible marijuana products are often indistinguishable in appearance from normal food items and lack the smell and visible smoke associated with inhaled marijuana. Because they are inconspicuous, palatable, and easily accessible, they are increasingly popular among adolescents. Additionally, the packaging of edible baked goods, candies, and drinks is often purposefully very similar to that of mainstream foods, increasing the risk of accidental ingestion by children. An edible marijuana product must be digested before Δ9-tetrahydrocannabinol can enter the bloodstream, so there is a delayed onset of effects when consuming edibles compared with inhaling marijuana. This also predisposes users to accidental overconsumption.

SUMMARY

Greater knowledge of edible marijuana product consumption by pediatric populations will allow pediatricians to more effectively help patients and advise caregivers in cases of overconsumption, dependence, or accidental ingestion. It is important for parents, guardians, and educators to be able to successfully identify edible marijuana products and recognize signs of cannabis use.