The effects of cannabis and alcohol on simulated arterial driving: Influences of driving experience and task demand

The effect of cannabis edibles on driving and blood THC

BACKGROUND

Cannabis has been shown to impact driving due to changes produced by delta-9-tetrahydrocannabinol (THC), the psychoactive component of cannabis. Current legal thresholds for blood THC while driving are based predominantly on evidence utilizing smoked cannabis. It is known that levels of THC in blood are lower after eating cannabis as compared to smoking yet the impact of edibles on driving and associated blood THC has never been studied.

METHODS

Participants drove a driving simulator before and after ingesting their preferred legally purchased cannabis edible. In a counterbalanced control session, participants did not consume any THC or cannabidiol (CBD). Blood was collected for measurement of THC and metabolites as well as CBD. Subjective experience was also assessed.

RESULTS

Participants consumed edibles with, on average, 7.3 mg of THC, which is less than the maximum amount available in a single retail package in Ontario, providing an ecologically valid test of cannabis edibles. Compared to control, cannabis edibles produced a decrease in mean speed 2 h after consumption but not at 4 and 6 h. Under dual task conditions in which participants completed a secondary task while driving, changes in speed were not significant after the correction for multiple comparison. No changes in standard deviation of lateral position (SDLP; 'weaving'), maximum speed, standard deviation of speed or reaction time were found at any time point or under either standard or dual task conditions. Mean THC levels were significantly increased, relative to control, after consuming the edible but remained relatively low at approximately 2.8 ng/mL 2 h after consumption. Driving impairment was not correlated with blood THC. Subjective experience was altered for 7 h and participants were less willing/able to drive for up to 6 h, suggesting that the edible was intoxicating.

INTERPRETATION

This is the first study of the impact of cannabis edibles on simulated driving. Edibles were intoxicating as revealed by the results of subjective assessments (VAS), and there was some impact on driving. Detection of driving impairment after the use of cannabis edibles may be difficult.

Interactive effects of alcohol and cannabis quantities in the prediction of same-day negative consequences among young adults

BACKGROUND

Simultaneous alcohol and cannabis use is common, but observational studies examining negative consequences of simultaneous use have rarely considered dose-related interactions between alcohol and cannabis. This study examined interactions between quantities of cannabis and alcohol consumed in predicting negative consequences on simultaneous use days.

METHODS

Young adults (N = 151; 64% female; 62% White) reporting recent simultaneous use and at least weekly alcohol and cannabis use completed 21 daily, smartphone-based surveys assessing previous day quantities of cannabis and alcohol used, types of cannabis used (flower, concentrates, edibles), and negative substance-related consequences. Multilevel models examined: (1) whether negative consequences differed within-person across simultaneous use days and single-substance use days; and (2) whether quantities of alcohol and cannabis consumed on simultaneous use days interacted, within-person, to predict negative consequences. We focused on quantities of cannabis flower (grams) in primary analyses and explored quantities of other forms of cannabis (concentrates, edibles) in supplementary analyses.

RESULTS

Participants reported fewer negative consequences on alcohol-only (243 observations) and cannabis-only (713 observations) days than they did on simultaneous use days (429 observations). On simultaneous use days involving cannabis flower use (313 observations across 81 participants), the within-person association between number of standard drinks and negative consequences was weaker on days during which larger (vs. smaller) amounts of cannabis flower were consumed. Inspection of simple slopes revealed that decreased alcohol use was associated with less of a decline in negative consequences when combined with relatively greater amounts of cannabis flower.

CONCLUSIONS

Although simultaneous use was associated with more negative consequences than alcohol-only and cannabis-only use, negative consequences on simultaneous use days varied as a function of the interaction between alcohol and cannabis quantities. As findings suggest that using larger amounts of cannabis may attenuate declines in negative consequences associated with lighter drinking, interventions for higher-risk simultaneous use patterns may benefit from a focus on quantities of both alcohol and cannabis.

A semi-naturalistic open-label study examining the effect of prescribed medical cannabis use on simulated driving performance

BACKGROUND

Despite increasing medical cannabis use, research has yet to establish whether and to what extent products containing delta-9-tetrahydrocannabinol (THC) impact driving performance among patients. Stable doses of prescribed cannabinoid products during long-term treatment may alleviate clinical symptoms affecting cognitive and psychomotor performance.

AIM

To examine the effects of open-label prescribed medical cannabis use on simulated driving performance among patients.

METHODS

In a semi-naturalistic laboratory study, 40 adults (55% male) aged between 23 and 80 years, consumed their own prescribed medical cannabis product. Driving performance outcomes including standard deviation of lateral position (SDLP), the standard deviation of speed (SDS), mean speed and steering variability were evaluated using the Forum8 driving simulator at baseline (pre-dosing), 2.5 h and 5 -h (post-dosing). Perceived driving effort (PDE) was self-reported after each drive. Oral fluid and whole blood samples were collected at multiple timepoints and analysed for THC via liquid chromatography-mass spectrometry.

RESULTS

A significant main effect of time was observed for mean speed (p = 0.014) and PDE (p = 0.020), with patients displaying modest stabilisation of vehicle control, increased adherence to speed limits and reductions in PDE post-dosing, relative to baseline. SDLP (p = 0.015) and PDE (p = 0.043) were elevated for those who consumed oil relative to flower-based products. Detectable THC concentrations were observed in oral fluid at 6-h post-dosing (range = 0-24 ng/mL).

CONCLUSIONS

This semi-naturalistic study suggests that the consumption of medical cannabis containing THC (1.13-39.18 mg/dose) has a negligible impact on driving performance when used as prescribed.

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.

Cannabis and Driving in Older Adults

Importance

Epidemiological studies have found that cannabis increases the risk of a motor vehicle collision. Cannabis use is increasing in older adults, but laboratory studies of the association between cannabis and driving in people aged older than 65 years are lacking.

Objective

To investigate the association between cannabis, simulated driving, and concurrent blood tetrahydrocannabinol (THC) levels in older adults.

Design, Setting, and Participants

Using an ecologically valid counterbalanced design, in this cohort study, regular cannabis users operated a driving simulator before, 30 minutes after, and 180 minutes after smoking their preferred legal cannabis or after resting. This study was conducted in Toronto, Canada, between March and November 2022 with no follow-up period. Data were analyzed from December 2022 to February 2023.

Exposures

Most participants chose THC-dominant cannabis with a mean (SD) content of 18.74% (6.12%) THC and 1.46% (3.37%) cannabidiol (CBD).

Main outcomes and measures

The primary end point was SD of lateral position (SDLP, or weaving). Secondary outcomes were mean speed (MS), maximum speed, SD of speed, and reaction time. Driving was assessed under both single-task and dual-task (distracted) conditions. Blood THC and metabolites of THC and CBD were also measured at the time of the drives.

Results

A total of 31 participants (21 male [68%]; 29 White [94%], 1 Latin American [3%], and 1 mixed race [3%]; mean [SD] age, 68.7 [3.5] years), completed all study procedures. SDLP was increased and MS was decreased at 30 but not 180 minutes after smoking cannabis compared with the control condition in both the single-task (SDLP effect size [ES], 0.30; b = 1.65; 95% CI, 0.37 to 2.93; MS ES, -0.58; b = -2.46; 95% CI, -3.56 to -1.36) and dual-task (SDLP ES, 0.27; b = 1.75; 95% CI, 0.21 to 3.28; MS ES, -0.47; b = -3.15; 95% CI, -5.05 to -1.24) conditions. Blood THC levels were significantly increased at 30 minutes but not 180 minutes. Blood THC was not correlated with SDLP or MS at 30 minutes, and SDLP was not correlated with MS. Subjective ratings remained elevated for 5 hours and participants reported that they were less willing to drive at 3 hours after smoking.

Conclusions and relevance

In this cohort study, the findings suggested that older drivers should exercise caution after smoking cannabis.

Self-Regulation of Driving Behavior Under the Influence of Cannabis: The Role of Driving Complexity and Driver Vision

OBJECTIVE

This study analyzed the self-regulation behaviors of drivers under the influence of cannabis and its relationship with road complexity and some driver traits, including visual deterioration.

BACKGROUND

Cannabis is the illicit drug most often detected in drivers; its use results in significant negative effects in terms of visual function. Self-regulation behaviors involve the mechanisms used by drivers to maintain or reduce the risk resulting from different circumstances or the driving environment.

METHODS

Thirty-one young, occasional cannabis users were assessed both in a baseline session and after smoking cannabis. We evaluated the visual function (visual acuity and contrast sensitivity) and driver self-regulation variables of both longitudinal and lateral control as the speed adaptation and standard deviation of lateral position (SDLP).

RESULTS

Visual function was significantly impaired after cannabis use. Recreational cannabis use did not result in self-regulation, although some road features such as curved roads did determine self-regulation. Male participants adopted mean faster driving speeds with respect to the speed limit. Driver age also determined better lateral control with lower SDLPs. In addition, visual impairment resulting from cannabis use (contrast sensitivity) was linked with self-regulation by changes in longitudinal and lateral control.

CONCLUSION

Contrast sensitivity could be a good indicator of individual visual status to help determine how drivers self-regulate their driving both in normal conditions and while under the influence of cannabis.

APPLICATION

The findings provide new insights about driver self-regulation under cannabis effects and are useful for policy making and awareness campaigns.

The Association Between Vaping and Driving Under the Influence of Cannabis Among U.S. Young Adults

INTRODUCTION

Driving under the influence of cannabis is a significant public health concern that is particularly common in young adults (aged 18-25 years) and has increased in recent years. Vaping has also dramatically increased, particularly among young populations, and is frequently used for cannabis administration among young adults. Therefore, this study aimed to examine the positive association between vaping and cannabis driving under the influence among young adults (aged 18-25 years).

METHODS

This study used the 2020 National Survey on Drug Use and Health and included young adults aged 18-25 years. This study examined past-year cannabis driving under the influence prevalence by past-year vaping at the intersection of past-year cannabis use, after adjusting for other associated factors such as race/ethnicity, sex, employment status, past-year other tobacco use, past-year serious psychological distress, and past-year driving under the influence of alcohol. Data were analyzed in 2022.

RESULTS

Among a sample of 7,860 U.S. individuals aged 18-25 years, 23.8% vaped in the past year, and 9.7% reported past-year cannabis driving under the influence. Past-year vaping was positively associated with past-year cannabis use (adjusted prevalence ratio=2.12; 95% CI=1.91, 2.35). Among those with cannabis use in the past year, past-year vaping was positively associated with past-year cannabis driving under the influence (adjusted prevalence ratio=1.52; 95% CI=1.25, 1.84).

CONCLUSIONS

This study found positive associations between past-year vaping, cannabis use, and cannabis driving under the influence among U.S. young adults, indicating that vaping was positively associated with cannabis use. Vaping was also positively associated with cannabis driving under the influence among those who used cannabis. This preliminary evidence could inform prevention/intervention strategies related to vaping and cannabis driving under the influence.

Medicinal Cannabis and Implications for Workplace Health and Safety: Scoping Review of Systematic Reviews

PURPOSE

Although medicinal cannabis is prescribed for conditions such as pain, epilepsy, nausea and vomiting during cancer treatment, evidence about associated adverse side effects is still evolving. Because adverse events (AEs) might impact the performance of workers, it is important to consider their implications on workplace health and safety (WHS). This study aimed to map the types and prevalence of the AEs associated with medical cannabis and articulate how those events could impact WHS.

METHODS

A scoping review of systematic reviews and/or meta-analyses published between 2015 and March 2021 was performed to identify the AEs of medicinal cannabis in adults. Publications in English and full text available online were collected from Embase, MEDLINE, PsychINFO, PubMed, Scopus, and Web of Science.

RESULTS

Of 1,326 papers identified from the initial search, 31 met the inclusion criteria and were analyzed. The studies reported various AEs with the most predominant being sedation, nausea/vomiting, dizziness, and euphoria. Acute and chronic pain was the most prevalent disorder under review.

CONCLUSIONS

Adverse events associated with the use of medicinal cannabis could increase workplace risks, including decreased alertness and reaction times, increased absenteeism, reduced ability to safely drive or operate machinery and an increased probability of falling. Focused research into the risk to workers and workplaces from the use of medical cannabis and related human performance impairment is urgently warranted.

Australian daily cannabis users' use of police avoidance strategies and compensatory behaviours to manage the risks of drug driving

INTRODUCTION

Daily use of cannabis is increasing in Australia, yet there is limited understanding of the driving behaviours within this cohort, including how they perceive and manage the risks of being apprehended for drug driving and involved in a crash after consumption.

METHODS

An online survey was completed by 487 Australians who reported daily cannabis use (30% medically prescribed patients, 58% male).

RESULTS

Current drug driving (i.e., driving within 4 h of consuming cannabis each week) was reported by 86% of participants. Future drug driving was anticipated by 92% of the sample. While most participants (93%) disagreed that their risk of crash increased following cannabis use, participants reported that they would drive more carefully (89%), leave greater headway (79%) and/or drive slower (51%) following cannabis consumption. Half of the sample (53%) perceived the risk of apprehension for drug driving to be likely to some extent. Strategies to reduce the likelihood of being detected were used by 25% of participants, and included using Facebook police location sites (16%), driving on back roads (6%) and/or consuming substances to mask the presence of drugs (13%). The regression analysis revealed that individuals who reported more occasions of cannabis use per day, and who perceived that cannabis does not reduce driving ability, reported a greater extent of current drug driving.

DISCUSSION AND CONCLUSIONS

Interventions and education which aim to challenge this perception that 'cannabis does not reduce driving ability' may prove important for reducing drug driving among the most frequent consumers of cannabis.

Drunk driving: a secondary analysis of factors associated with driving under the influence of alcohol in Jamaica

OBJECTIVES

To determine the prevalence of alcohol use patterns, sociodemographic factors and risk of alcohol dependence among vehicle drivers in Jamaica.

DESIGN

A secondary data analysis.

SETTING

This study was conducted using the Jamaica National Drug Prevalence Survey 2016 dataset.

PARTICIPANTS

This included 1060 vehicle drivers derived from the population sample of 4623. The participants from each household were randomly selected as the respondent for the survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

Alcohol use and dependence were measured using the Alcohol Use Disorders Identification Test questionnaire. Driving under the influence of alcohol (DUIA) was assessed by questions regarding its use in the past 12 months. The analysis involved the use of Pearson's χ2 test and logistic regression.

RESULTS

75% of Jamaicans reported lifetime alcohol use. Approximately 65% of drivers indicated that they currently drink alcohol. 18% of drivers who currently drink alcohol admitted to DUIA. Reportedly, 54.5% of these drivers were alcohol binge drinkers, with 41.5% also driving under the influence of cannabis. The bivariate analysis demonstrated that DUIA was higher among Christian participants and those who worked in non-machine operator jobs (p=0.002 and p=0.008, respectively). Vehicle drivers altogether and drivers who drive under the influence of alcohol had significant associations with hazardous drinking (p=0.011 and p<0.001, respectively). Logistic regressions highlighted drivers 34 years and under (p=0.012), male drivers (p=0.002) and the head of the household (p=0.050) were 1.82, 3.30 and 1.86 times more likely, respectively, to report driving under the influence of alcohol in the past year.

CONCLUSIONS

The prevalence of alcohol use among Jamaica's population and vehicle drivers is high. That one in five drivers, who currently consume alcohol, also admits to driving under the influence suggests the urgent need for mitigation strategies and legislative action as part of a preventative effort to reduce drunk driving.

Collisions and cannabis: Measuring the effect of recreational marijuana legalization on traffic crashes in Washington State

OBJECTIVE

Washington State was among the first states in the US to legalize recreational consumption and retail sales of marijuana. Recreational use of cannabis was legalized December 6, 2012, following the passage of Initiative 502 30 days prior. Roughly 19 months later the first retail cannabis stores opened their doors for public sales ("commercialization"). I measure the impact of cannabis legalization and commercialization on traffic collisions in Washington State.

METHODS

With county-level vehicle crash data from the Washington State Department of Transportation collected monthly, I utilize an interrupted time-series framework with Poisson estimation to compare traffic collisions with recreational retail cannabis sales revenue from 2011 (three years pre-commercialization) through 2017 (three years post-commercialization). First, I measure the shift in collisions brought about by Washington's 2012 cannabis legalization. Then, I compare retail cannabis sales-a measure of commercialization-to traffic collisions based on severity of injury (fatal, severe injury, minor injury, non-injury, and all).

RESULTS

After controlling for confounding factors, evidence suggests that recreational cannabis legalization led to fewer fatal and serious injury collisions. Retail cannabis sales generally correlate with more traffic collisions, particularly for less severe (minor injury) crashes. These findings are robust to the inclusion of additional control variables pertaining to county-level cannabis usage and driving behavior while intoxicated.

CONCLUSIONS

Cannabis legalization led to fewer fatal, serious, and minor injury collisions. Commercialization (cannabis sales) correlated with an increase in less severe crashes. Although cannabis use generally increased in Washington State following legalization/commercialization, survey data suggest that driving behavior while under the influence of cannabis did not change significantly over the post-commercialization period. Future research should focus on measuring the dose-dependent impact of cannabis consumption on traffic collisions. This should include recognition of the importance of cannabis dosing, timing, and route of consumption. Lastly, the dangers of poly-drug driving-particularly cannabis and alcohol-are well established and should be high priority for further research.

Preliminary study of the interactive effects of THC and ethanol on self-reported ability and simulated driving, subjective effects, and cardiovascular responses

RATIONALE

Drug- and alcohol-related motor vehicle accidents are a leading cause of morbidity and mortality worldwide. Compared to alcohol, less is known about the effects of cannabis on driving and even less about their combined effects.

OBJECTIVE

To characterize the combined and separate effects of ethanol and tetrahydrocannabinol (THC) on perceived ability to drive, subjective effects, and simulated driving.

METHODS

In a within-subject (crossover), randomized, placebo-controlled, double-blind, 2 × 2 design, the effects of oral THC (10 mg [dronabinol] or placebo) and low-dose intravenous ethanol (clamped at BAC 0.04% or placebo) on perceived ability to drive, simulated driving (standard deviation of lateral position [SDLP]), subjective effects (e.g., "high"), and physiological effects (e.g., heart rate) were studied in healthy humans (n = 18).

RESULTS

Subjects reported reductions in perceived ability to drive (THC < ethanol < combination) which persisted for ~ 6 h (placebo = ethanol, THC < combination). Ethanol and THC produced synergistic effects on heart rate, significant differences compared to either drug alone on perceived ability to drive and feeling states of intoxication (e.g., high), as well increases in SDLP compared to placebo.

CONCLUSIONS

Perceived ability to drive is reduced under the influence of THC against the backdrop of blood alcohol levels that are below the legal limit. People should be aware that the effects of oral THC on driving may persist for up to six hours from administration. Findings are relevant to the increasingly common practice of combining alcohol and cannabinoids and the effects on driving.

Effect of CannEpil® on simulated driving performance and co-monitoring of ocular activity: A randomised controlled trial

BACKGROUND

Medicinal cannabis products containing Δ9-tetrahydrocannabinol (THC) are increasingly accessible. Yet, policy guidelines regarding fitness to drive are lacking, and cannabinoid-specific indexations of impairment are underdeveloped.

AIMS

To determine the impact of a standardised 1 mL sublingual dose of CannEpil^®, a medicinal cannabis oil containing 100 mg cannabidiol (CBD) and 5 mg THC on simulated driving performance, relative to placebo and whether variations in vehicle control can be indexed by ocular activity.

METHODS

A double-blind, within-subjects, randomised, placebo-controlled, crossover trial assessed 31 healthy fully licensed drivers (15 male, 16 female) aged between 21 and 58 years (M = 38.0, SD = 10.78). Standard deviation of lateral position (SDLP), standard deviation of speed (SDS) and steering variability were assessed over time and as a function of treatment during a 40 min simulated drive, with oculomotor parameters assessed simultaneously. Oral fluid and plasma were collected at 30 min and 2.5 h.

RESULTS

CannEpil did not significantly alter SDLP across the full drive, although increased SDLP was observed between 20 and 30 min (p < 0.05). CannEpil increased SDS across the full drive (p < 0.05), with variance greatest at 20-30 min (p < 0.001). CannEpil increased fixation duration (p < 0.05), blink rate (trend p = 0.051) and decreased blink duration (p < 0.001) during driving. No significant correlations were observed between biological matrices and performance outcomes.

CONCLUSIONS

CannEpil impairs select aspects of vehicle control (speed and weaving) over time. Alterations to ocular behaviour suggest that eye tracking may assist in determining cannabis-related driver impairment or intoxication. Australian and New Zealand Clinician Trials Registry, https://anzctr.org.au(ACTRN12619000932167).

Risk Factors Associated With Driving After Marijuana Use Among US College Students During the COVID-19 Pandemic

PURPOSE

To assess the sociodemographic and behavioral risk factors associated with driving after marijuana use among US college students.

METHODS

A secondary analysis used the fall 2020 and spring 2021 American College Health Association- National College Health Assessment III and the dataset was restricted to college students ≥18 years of age who reported recent driving and marijuana use. Associations between risk factors and driving after marijuana use were estimated using multivariable logistic regression.

RESULTS

A total of 29.9% (n = 4,947) of the respondents reported driving after marijuana use. Males (adjusted odds ratio [AOR]: 1.64, 95% confidence interval [CI]: 1.48-1.82), non-Hispanic Black (AOR: 1.32, 95% CI: 1.02-1.71), sexual minorities (AOR: 1.19, 95% CI: 1.07-1.31), individuals with an alcohol or substance use disorder (AOR: 1.44, 95% CI: 1.08-1.91), anxiety (AOR: 1.20, 95% CI: 1.06-1.36), higher suicidality (AOR: 1.18, 95% CI: 1.07-1.31), and those who also drank and drove (AOR: 3.18, 95% CI: 2.84-3.57) had a higher risk of driving after marijuana use.

DISCUSSION

Future research should focus on increasing awareness of driving after marijuana use and prevention programs and/or strategies on college campuses regarding driving after marijuana use for these groups to reduce this risky behavior.

Study design to evaluate a web-intervention to prevent alcohol and cannabis-impaired driving and use among adolescents in driver education

BACKGROUND

Alcohol and cannabis are the most commonly used substances among adolescents in the U.S. The consequences related to using both substances together are significantly higher relative to use of either substance alone. Teens' propensity to engage in risky driving behaviors (e.g., speeding, rapid lane changes, and texting) and their relative inexperience with the timing and duration of cannabis' effects puts them at heightened risk for experiencing harms related to driving under the influence. Use of alcohol and cannabis peak at age 16, the legal age teens may apply for a provisional driver's license in some states. Targeting novice teen drivers prior to licensure is thus an ideal time for prevention efforts focused on reducing alcohol and/or cannabis initiation, use, and impaired driving.

METHODS

The current study proposes to evaluate the efficacy of webCHAT among 15.5 to 17-year-old adolescents (n = 150) recruited at driver education programs. WebCHAT is a single session online intervention that aims to prevent alcohol and cannabis use and risky driving behaviors. We will recruit adolescents enrolled in driver education programs, and stratify based on whether they used cannabis and/or alcohol in the past 3 months (60% screening negative and 40% screening positive). All participants will receive usual driver education and half will also receive webCHAT. We will test whether webCHAT in addition to usual driver education reduces alcohol and/or cannabis initiation or use and reduces risky driving attitudes and behaviors (intent to drive after drinking/using, riding as a passenger with someone who drank/used) compared to teens in usual driver education over a 6-month period. We will also explore whether variables such as beliefs and perceived norms serve as explanatory mechanisms for our outcomes.

DISCUSSION

The study has the potential to promote public welfare by decreasing adolescent initiation and use of cannabis and alcohol and reducing risky driving behaviors that can have substantial monetary, personal, and social costs. The study recruits adolescents who are at risk for substance use as well as those who are not and it is delivered remotely during a teachable moment when adolescents receive driver education. Trial registration This study was registered with ClinicalTrials.gov on July 13, 2021 (NCT04959461). https://clinicaltrials.gov/ct2/show/NCT04959461.

The Utility of THC Cutoff Levels in Blood and Saliva for Detection of Impaired Driving

Background: Δ9-Tetrahydrocannabinol (THC) is the psychoactive component in cannabis and a relationship of THC to driving impairment is expected. Despite this, there are discrepant findings with respect to the relationship of blood THC to driving. This study investigated the relationship of blood, urine, and saliva THC/THC-COOH levels to "weaving," as measured by a driving simulator. Methods: Participants smoked cannabis alone or with alcohol. THC/THC-COOH levels in blood, urine, and saliva were correlated with standard deviation of lateral position (SDLP), measuring "weaving." In addition, SDLP after cannabis and/or alcohol were compared with SDLP after placebo when THC/THC-COOH levels were above or below specified thresholds in blood (5 ng/mL), urine (50 ng/mL), or saliva (25 ng/mL). Results: A clear linear relationship between blood THC concentration and SDLP was not observed based on calculation of Spearman coefficients. When compared with placebo, SDLP was significantly increased after cannabis and cannabis combined with alcohol when THC in the blood was above the legal limit. SDLP was increased in drug conditions when saliva cutoffs were above the legal limit. Conclusions: The findings of this study suggest that specified thresholds for THC in blood and saliva may be able to detect driving impairment, but future studies are needed. ClinicalTrials.gov ID: NCT03106363.

Does expanding access to cannabis affect traffic crashes? County-level evidence from recreational marijuana dispensary sales in Colorado

This article examines the effect of recreational cannabis dispensary sales on traffic crashes by employing difference-in-differences model that exploits the variation in the timing of recreational marijuana dispensary entry across counties within Colorado. Using marijuana-related hospital discharge as a measure of marijuana abuse/misuse, the results indicate a sizable rise in marijuana-related hospital discharges after the entry of retail cannabis stores. However, there is a lack of evidence that traffic crash incidents are affected by the entry. The preferred estimate suggests that, at 90% confidence level, a large increase in traffic crashes by more than 5% can be ruled out.

Medical cannabis and automobile accidents: Evidence from auto insurance

While many states have legalized medical cannabis, many unintended consequences remain under-studied. We focus on one potential detriment-the effect of cannabis legalization on automobile safety. We examine this relationship through auto insurance premiums. Employing a modern difference-in-differences framework and zip code-level premium data from 2014 to 2019, we find that premiums declined, on average, by $22 per year following medical cannabis legalization. The effect is more substantial in areas near a dispensary and in areas with a higher prevalence of drunk driving before legalization. We estimate that existing legalization has reduced health expenditures related to auto accidents by almost $820 million per year with the potential for a further $350 million reduction if legalized nationally.

Admissions to substance use treatment facilities for cannabis use disorder, 2000-2017: Does legalization matter?

BACKGROUND AND OBJECTIVES

A growing number of US states have legalized marijuana use in the past decade. We examined if marijuana legalization is associated with increased marijuana-related admissions to substance use treatment facilities between 2000 and 2017.

METHODS

Data from the Treatment Episode Data Set-Admissions were used to examine the relationship between marijuana-related admissions among adults aged ≥18 by year and legalization status (i.e., fully legalized, medical use only [partially legalized], and illegal) (N = 35,457,854). Using interaction analyses, we further examined whether certain patient characteristics were associated with residence in states that legalized marijuana use as compared to those in which marijuana remained illegal.

RESULTS

Overall, the proportion of marijuana-related admissions in states with legalization decreased by 2.3% from 31.7% in 2000-2005 to 29.4% in 2012-2017 (odds ratio [OR], 0.90; 95% confidence intervals [CI], 0.89-0.90) with little difference from states where marijuana use remained illegal, in which marijuana use as any reason for admissions decreased by 0.3% from 39.8% in 2000-2005 to 39.5% in 2012-2017 (OR, 0.99; 95% CI, 0.98-0.99). We did not find any striking patient characteristics (e.g., referral by the police) associated with admissions in states that legalized compared to those that had not.

DISCUSSION AND CONCLUSIONS

While earlier studies suggested that marijuana legalization is associated with increased levels of use, emergency department visits, and traffic fatalities, our findings suggest that marijuana legalization did not increase marijuana-related treatment use in the United States.

SCIENTIFIC SIGNIFICANCE

This is the first study to examine the association of marijuana legalization with marijuana-related treatment use.

Simultaneous Alcohol/Cannabis Use and Driving Under the Influence in the U.S

INTRODUCTION

Alcohol and cannabis are commonly involved in motor vehicle crashes and fatalities. This study examines whether simultaneous use of alcohol/cannabis is associated with higher odds of reporting driving under the influence of alcohol and cannabis in the U.S.

METHODS

Drivers aged ≥16 years with any past-year alcohol and cannabis use in the 2016-2019 National Survey on Drug Use and Health (N=34,514) reported any past-year driving under the influence of alcohol-only, cannabis-only, both alcohol/cannabis, or not driving under the influence. Survey-weighted associations between simultaneous alcohol/cannabis use and each of the driving under the influence outcomes were computed adjusting for sociodemographics and daily alcohol/cannabis use. Analyses were conducted from November 2020 to September 2021.

RESULTS

In 2016-2019, 42% of drivers with past-year alcohol and cannabis use reported driving under the influence (8% alcohol-only, 20% cannabis-only, 14% alcohol/cannabis). Simultaneous alcohol/cannabis use was associated with 2.88-times higher adjusted odds of driving under the influence of cannabis-only (95% CI=2.59, 3.19) and 3.51-times higher adjusted odds of driving under the influence of both alcohol/cannabis (95% CI=3.05, 4.05), compared to not driving under the influence. Associations with driving under the influence of alcohol-only were unexpectedly in the opposite direction (adjusted conditional odds ratio=0.59, 95% CI=0.45, 0.79).

CONCLUSIONS

Overall, 2 in 5 drivers who used alcohol and cannabis reported driving under the influence of alcohol and/or cannabis. People reporting simultaneous alcohol/cannabis use were more likely to report cannabis-related driving under the influence. Prevention strategies should target individuals reporting simultaneous alcohol/cannabis use to reduce the occurrence of driving under the influence.

Combined effect of alcohol and cannabis on simulated driving

RATIONALE

With alcohol and cannabis remaining the most commonly detected drugs in seriously and fatally injured drivers, there is a need to understand their combined effects on driving.

OBJECTIVES

The present study examined the effects of combinations of smoked cannabis (12.5% THC) and alcohol (target BrAC 0.08%) on simulated driving performance, subjective drug effects, cardiovascular measures, and self-reported perception of driving ability.

METHODS

In this within-subjects, double-blind, double-dummy, placebo-controlled, randomized clinical trial, cannabis users (1-7 days/week) aged 19-29 years attended four drug administration sessions in which simulated driving, subjective effects, cardiovascular measures, and whole blood THC and metabolite concentrations were assessed following placebo alcohol and placebo cannabis (<0.1% THC), alcohol and placebo cannabis, placebo alcohol and active cannabis, and alcohol and active cannabis.

RESULTS

Standard deviation of lateral position in the combined condition was significantly different from the placebo condition (p < 0.001). Standard deviation of lateral position was also significantly different from alcohol and cannabis alone conditions in the single task overall drive (p = 0.029 and p = 0.032, respectively), from the alcohol alone condition in the dual task overall drive (p = 0.022) and the cannabis alone condition in the dual task straightaway drive (p = 0.002). Compared to the placebo condition, the combined and alcohol conditions significantly increased reaction time. Subjective effects in the combined condition were significantly greater than with either of the drugs alone at some time points, particularly later in the session. A driving ability questionnaire showed that participants seemed unaware of their level of impairment.

CONCLUSION

Combinations of alcohol and cannabis increased weaving and reaction time, and tended to produce greater subjective effects compared to placebo and the single drug conditions suggesting a potential additive effect. The fact that participants were unaware of this increased effect has important implications for driving safety.

Driving under the influence of drugs: Correlation between blood psychoactive drug concentrations and cognitive impairment. A narrative review taking into account forensic issues

Driving under the influence of alcohol has been shown to increase the risk of involvement in road traffic collisions (RTCs) however, less is known about the effects of illicit drugs, and a clear correlation between drug concentrations and RTC risk is still debated. The goal of this narrative review is to assess the current literature regarding the most detected psychoactive drugs in RTC (ethanol, amphetamines, cannabis, opioids and cocaine), in relation to driving performance. Evidence on impaired driving due to psychoactive substances, forensic issues relating to the assessment of the impact of drugs, blood cut-off values proposed to date as well as scientific basis for proposed legislative limits are discussed. At present there is no unequivocal evidence demonstrating a clear dose/concentration dependent impairment in many substances. Per se and zero tolerance approaches seem to have negative effect on drugged driving fatalities. However, the weight of these approaches needs further investigation.

Driving Performance and Cannabis Users' Perception of Safety: A Randomized Clinical Trial

IMPORTANCE

Expanding cannabis medicalization and legalization increases the urgency to understand the factors associated with acute driving impairment.

OBJECTIVE

To determine, in a large sample of regular cannabis users, the magnitude and time course of driving impairment produced by smoked cannabis of different Δ9-tetrahydrocannabinol (THC) content, the effects of use history, and concordance between perceived impairment and observed performance.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind, placebo-controlled parallel randomized clinical trial took place from February 2017 to June 2019 at the Center for Medicinal Cannabis Research, University of California San Diego. Cannabis users were recruited for this study, and analysis took place between April 2020 and September 2021.

INTERVENTIONS

Placebo or 5.9% or 13.4% THC cannabis smoked ad libitum.

MAIN OUTCOMES AND MEASURES

The primary end point was the Composite Drive Score (CDS), which comprised key driving simulator variables, assessed prior to smoking and at multiple time points postsmoking. Additional measures included self-perceptions of driving impairment and cannabis use history.

RESULTS

Of 191 cannabis users, 118 (61.8%) were male, the mean (SD) age was 29.9 (8.3) years, and the mean (SD) days of use in the past month was 16.7 (9.8). Participants were randomized to the placebo group (63 [33.0%]), 5.9% THC (66 [34.6%]), and 13.4% THC (62 [32.5%]). Compared with placebo, the THC group significantly declined on the Composite Drive Score at 30 minutes (Cohen d = 0.59 [95% CI, 0.28-0.90]; P < .001) and 1 hour 30 minutes (Cohen d = 0.55 [95% CI, 0.24-0.86]; P < .001), with borderline differences at 3 hours 30 minutes (Cohen d = 0.29 [95% CI, -0.02 to 0.60]; P = .07) and no differences at 4 hours 30 minutes (Cohen d = -0.03 [95% CI, -0.33 to 0.28]; P = .87). The Composite Drive Score did not differ based on THC content (likelihood ratio χ24 = 3.83; P = .43) or use intensity (quantity × frequency) in the past 6 months (likelihood ratio χ24 = 1.41; P = .49), despite postsmoking blood THC concentrations being higher in those with the highest use intensity. Although there was hesitancy to drive immediately postsmoking, increasing numbers (81 [68.6%]) of participants reported readiness to drive at 1 hour 30 minutes despite performance not improving from initial postsmoking levels.

CONCLUSIONS AND RELEVANCE

Smoking cannabis ad libitum by regular users resulted in simulated driving decrements. However, when experienced users control their own intake, driving impairment cannot be inferred based on THC content of the cigarette, behavioral tolerance, or THC blood concentrations. Participants' increasing willingness to drive at 1 hour 30 minutes may indicate a false sense of driving safety. Worse driving performance is evident for several hours postsmoking in many users but appears to resolve by 4 hours 30 minutes in most individuals. Further research is needed on the impact of individual biologic differences, cannabis use history, and administration methods on driving performance.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02849587.

Effects of High-Potency Cannabis on Psychomotor Performance in Frequent Cannabis Users

Background: Recently increased access to cannabis products in the United States has been associated with increased rates of driving after cannabis use. Although numerous studies indicate that cannabis impairs psychomotor and neurocognitive functions that can affect driving ability, the determination of cannabis-impaired driving risk is complicated by the extent to which frequent cannabis users develop tolerance to THC's subjective, cognitive, and psychomotor effects, and by the fact that there is no validated behavioral or biological marker of recent cannabis use or cannabis-related impairment. This study examined the psychomotor impairment-related effects experienced by frequent cannabis users in Colorado after naturalistic consumption of smoked cannabis, both immediately and 1 h postuse. Results were then validated in a smaller replication sample from Washington state. Methods: In the primary Colorado study, participants (n=70) used the DRUID^® mobile app, a brief measure of psychomotor and cognitive domains that are sensitive to the effects of cannabis. First, participants used DRUID to establish a sober baseline impairment score. During a second appointment, they used DRUID at three time points: preuse, immediately after acutely using cannabis, and 1 h postuse. In the Washington replication sample, participants (n=39) used DRUID before acute cannabis consumption and then every half hour for 2.5 h. Results: In both studies, peak DRUID impairment effects were seen immediately after cannabis use, with recovery of performance at 1 h postuse. Specifically, significant quadratic effects of time emerged for both studies (Colorado study: (β=-0.935, SE=0.204, p<0.001); Washington study: β=3.0299, SE=1.3085, p<0.01). Domain-specific effects were tested in the larger Colorado study and were observed for reaction time within a complex divided attention task and a postural-stability balance task. Conclusions: These findings demonstrate that psychomotor impairment emerges immediately after acute cannabis use even in regular users, but decreases significantly 1 h postuse. These results underscore the potential utility of the DRUID app for assessing acute cannabis-related psychomotor impairment. Further research is needed to explore whether the DRUID app and/or the specific psychomotor functions it assesses might serve as a tool for measuring cannabis-related driving impairment. Clinical trials registration number for the Colorado Study: NCT03522103.

Medical marijuana for inflammatory bowel disease: the highs and lows

Increased interest in cannabis as a potential treatment and/or adjuvant therapy for inflammatory bowel disease (IBD) has been driven by patients with refractory disease seeking relief as well those who desire alternatives to conventional therapies. Available data have shown a potential role of cannabis as a supportive medication, particularly in pain reduction; however, it remains unknown whether cannabis has any impact on the underlying inflammatory process of IBD. The purpose of this review article is to summarize the available literature concerning the use of cannabis for the treatment of IBD and highlight potential areas for future study.

Driving under the influence: a multi-center evaluation of vehicular crashes in the era of cannabis legalization

Background

Eleven states have instituted laws allowing recreational cannabis use leading to growing public health concerns surrounding the effects of cannabis intoxication on driving safety. We hypothesized that after the 2016 legalization of cannabis in California, the use among vehicular injury patients would increase and be associated with increased injury severity.

Methods

San Diego County’s five adult trauma center registries in were queried from January 2010 to June 2018 for motor vehicle or motorcycle crash patients with completed toxicology screens. Patients were stratified as toxicology negative (TOX−), positive for only THC (THC+), only blood alcohol >0.08% (ETOH+), THC+ETOH, or THC+ with any combination with methamphetamine or cocaine (M/C). County medical examiner data were reviewed to characterize THC use in those with deaths at the scene of injury.

Results

Of the 11,491 patients identified, there were 61.6% TOX−, 11.7% THC+, 13.7% ETOH+, 5.0% THC+ETOH, and 7.9% M/C. THC+ increased from 7.3% to 14.8% over the study period and peaked at 14.9% post-legalization in 2017. Compared with TOX− patients, THC+ patients were more likely to be male and younger. THC+ patients were also less likely to wear seatbelts (8.5% vs 14.3%, p<0.001) and had increased mean Injury Severity Score (8.4±9.4 vs 9.0±9.9, p<0.001) when compared with TOX− patients. There was no difference in in-hospital mortality between groups. From the medical examiner data of the 777 deaths on scene, 27% were THC+.

Discussion

THC+ toxicology screens in vehicular injury patients peaked after the 2016 legalization of cannabis. Public education on the risks of driving under the influence of cannabis should be a component of injury prevention initiatives.

Level of evidence

III, Prognostic

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.

Simulated driving performance among daily and occasional cannabis users

OBJECTIVE

Daily cannabis users develop tolerance to some drug effects, but the extent to which this diminishes driving impairment is uncertain. This study compared the impact of acute cannabis use on driving performance in occasional and daily cannabis users using a driving simulator.

METHODS

We used a within-subjects design to observe driving performance in adults age 25 to 45 years with different cannabis use histories. Eighty-five participants (43 males, 42 females) were included in the final analysis: 24 occasional users (1 to 2 times per week), 31 daily users and 30 non-users. A car-based driving simulator (MiniSim™, National Advanced Driving Simulator) was used to obtain two measures of driving performance, standard deviation of lateral placement (SDLP) and speed relative to posted speed limit, in simulated urban driving scenarios at baseline and 30 min after a 15 min ad libitum cannabis smoking period. Participants smoked self-supplied cannabis flower product (15% to 30% tetrahydrocannabinol (THC). Blood samples were collected before and after smoking (30 min after the start of smoking). Non-users performed the same driving scenarios before and after an equivalent rest interval. Changes in driving performance were analyzed by repeated measures general linear models.

RESULTS

Mean whole blood THC cannabinoids concentrations post smoking were use THC = 6.4 ± 5.6 ng/ml, THC-COOH = 10.9 ± 8.79 ng/mL for occasional users and THC = 36.4 ± 37.4 ng/mL, THC-COOH = 98.1 ± 90.6 ng/mL for daily users. On a scale of 0 to 100, the mean post-use score of subjective high was similar in occasional users and daily users (52.4 and 47.2, respectively). In covariate-adjusted analysis, occasional users had a significant increase in SDLP in the straight road segment from pre to post compared to non-users; non-users decreased by a mean of 1.1 cm (25.5 cm to 24.4 cm) while occasional users increased by a mean of 1.9 cm (21.7 cm to 23.6 cm; p = 0.02). Daily users also increased adjusted SDLP in straight road segments from baseline to post-use (23.2 cm to 25.0 cm), but the change relative to non-users was not statistically significant (p = 0.08). The standardized mean difference in unadjusted SDLP from baseline to post-use in the straight road segments comparing occasional users to non-users was 0.64 (95% CI 0.09 - 1.19), a statistically significant moderate increase. When occasional users were contrasted with daily users, the baseline to post changes in SDLP were not statistically significant. Daily users exhibited a mean decrease in baseline to post-use adjusted speed in straight road segments of 1.16 mph; a significant change compared to slight speed increases in the non-users and occasional users (p = 0.02 and p = 0.01, respectively).

CONCLUSION

We observed a decrement in driving performance assessed by SDLP after acute cannabis smoking that was statistically significant only in the occasional users in comparison to the nonusers. Direct contrasts between the occasional users and daily users in SDLP were not statistically significant. Daily users drove slower after cannabis use as compared to the occasional use group and non-users. The study results do not conclusively establish that occasional users exhibit more driving impairment than daily users when both smoke cannabis ad libitum.

Preliminary Eye-Tracking Data as a Nonintrusive Marker for Blood Δ-9-Tetrahydrocannabinol Concentration and Drugged Driving

Background: Cannabis is one of the drugs most often found in drivers involved in serious motor vehicle collisions. Validity and reliability of roadside cannabis detection strategies are questioned. This pilot study aimed to investigate the relationship between eye characteristics and cannabis effects in simulated driving to inform potential development of an alternative detection strategy. Materials and Methods: Multimodal data, including blood samples, eye-tracking recordings, and driving performance data, were acquired from 10 participants during a prolonged single-session driving simulator experiment. The study session included a baseline driving trial before cannabis exposure and seven trials at various times over ∼5 h after exposure. The multidimensional eye-tracking recording from each driving trial for each participant was segmented into nonoverlapping epochs (time windows); 34 features were extracted from each epoch. Blood Δ-9-tetrahydrocannabinol (THC) concentration, standard deviation of lateral position (SDLP), and mean vehicle speed were target variables. The cross-correlation between the temporal profile of each eye-tracking feature and target variable was assessed and a nonlinear regression analysis evaluated temporal trend of features following cannabis exposure. Results: Mean pupil diameter (r=0.81-0.86) and gaze pitch angle standard deviation (r=0.79-0.87) were significantly correlated with blood THC concentration (p<0.01) for all epoch lengths. For driving performance variables, saccade-related features were among those showing the most significant correlation (r=0.61-0.83, p<0.05). Epoch length significantly affected correlations between eye-tracking features and speed (p<0.05), but not SDLP or blood THC concentration (p>0.1). Temporal trend analysis of eye-tracking features after cannabis also showed a significant increasing trend (p<0.01) in saccade-related features, including velocity, scanpath, and duration, as the influence of cannabis decreased by time. A decreasing trend was observed for fixation percentage and mean pupil diameter. Due to the lack of placebo control in this study, these results are considered preliminary. Conclusion: Specific eye characteristics could potentially be used as nonintrusive markers of THC presence and driving-related effects of cannabis. clinicaltrials.gov (NCT03813602).

Modeling takeover behavior in level 3 automated driving via a structural equation model: Considering the mediating role of trust

The takeover process in level 3 automated driving determines the controllability of the functions of automated vehicles and thereby traffic safety. In this study, we attempted to explain drivers' takeover performance variation in a level 3 automated vehicle in consideration of the effects of trust, system characteristics, environmental characteristics, and driver characteristics with a structural equation model. The model was built by incorporating drivers' takeover time and quality as endogenous variables. A theoretical framework of the model was hypothesized on the basis of the ACT-R cognitive architecture and relevant research results. The validity of the model was confirmed using data collected from 136 driving simulator samples under the condition of voluntary non-driving-related tasks. Results revealed that takeover time budget was the most critical factor in promoting the safety and stability of takeover process, which, together with traffic density, drivers' age and manual driving experience, determined drivers' takeover quality directly. In addition, the pre-existing experience with an automated system or a similar technology and self-confidence of the driver, as well as takeover time budget, strongly influenced the takeover time directly. Apart from the direct effects mentioned above, trust, as an intermediary variable, explained a major portion of the variance in takeover time. Theoretically, these findings suggest that takeover behavior could be comprehensively evaluated from the two dimensions of takeover time and quality through the combination of trust, driver characteristics, environmental characteristics, and vehicle characteristics. The influence mechanism of the above factors is complex and multidimensional. In addition to the form of direct influence, trust, as an intermediary variable, could reflect the internal mechanism of the takeover behavior variation. Practically, the findings emphasize the crucial role of trust in the change in takeover behavior through the dimensions of subjective trust level and monitoring strategy, which may provide new insights into the function design of takeover process.

Associations of Current and Remitted Cannabis Use Disorder With Health-related Quality of Life and Employment Among US Adults

BACKGROUND

The associations of current and remitted cannabis use disorder (CUD) with health-related quality of life (HRQOL) and employment have not been studied, and we aim to address these gaps.

METHODS

The 2012-2013 National Epidemiological Survey on Alcohol and Related Conditions III (NESARC III) surveyed a nationally representative sample of non-institutionalized civilian US adults (≥18 years) (n = 36,309 unweighted). Using DSM-5 criteria, adults with current CUD were compared with those with CUD in remission and no history of CUD on standard measures of the mental and physical component scores of HRQOL and of quality-adjusted life years (QALYs) along with employment in the past 12 months. Multivariable-adjusted regression analyses were used to adjust for and examine the role of covariates.

RESULTS

Overall, 2.5% of the study sample, representing 6.0 million adults nationwide, met criteria for current CUD, and 3.7%, representing 8.8 million adults, met the criteria for CUD in remission. Adults with current or past CUD had lower mental HRQOL and QALYs, as compared to adults who never had CUD. However, these differences were no longer significant when adjusted for behavioral co-morbidities and personal histories. Current CUD was associated with lower odds of being employed (Adjusted odds ratio AOR = 0.76; 95% confidence intervals [CI], 0.60-0.96), but CUD in remission with a greater likelihood of employment (Adjusted odds ratio = 1.53; 95% CI, 1.23-1.91), both as compared to those never experiencing CUD.

CONCLUSIONS

Both current CUD and past CUD are adversely associated with HRQOL and current CUD with not being employed; Since CUD associations are not independent of comorbidities, treatment must take a wide-ranging approach.

Medicinal cannabis and driving: the intersection of health and road safety policy

BACKGROUND

Recent shifting attitudes towards the medical use of cannabis has seen legal access pathways established in many jurisdictions in North America, Europe and Australasia. However, the positioning of cannabis as a legitimate medical product produces some tensions with other regulatory frameworks. A notable example of this is the so-called 'zero tolerance' drug driving legal frameworks, which criminalise the presence of THC (tetrahydrocannabinol) in a driver's bodily fluids irrespective of impairment. Here we undertake an analysis of this policy issue based on a case study of the introduction of medicinal cannabis in Australia.

METHODS

We examine the regulatory approaches used for managing road safety risks associated with potentially impairing prescription medicines and illicit drugs in Australian jurisdictions, as well as providing an overview of evidence relating to cannabis and road safety risk, unintended impacts of the 'zero-tolerance' approach on patients, and the regulation of medicinal cannabis and driving in comparable jurisdictions.

RESULTS

Road safety risks associated with medicinal cannabis appear similar or lower than numerous other potentially impairing prescription medications. The application of presence-based offences to medicinal cannabis patients appears to derive from the historical status of cannabis as a prohibited drug with no legitimate medical application. This approach is resulting in patient harms including criminal sanctions when not impaired and using the drug as directed by their doctor, or the forfeiting of car use and related mobility. Others who need to drive are excluded from accessing a needed medication and associated therapeutic benefit. 'Medical exemptions' for medicinal cannabis in comparable jurisdictions and other drugs included in presence offences in Australia (e.g. methadone) demonstrate a feasible alternative approach.

CONCLUSION

We conclude that in medical-only access models there is little evidence to justify the differential treatment of medicinal cannabis patients, compared with those taking other prescription medications with potentially impairing effects.

Prevalence and Correlates of Driving Under the Influence of Cannabis in the U.S

INTRODUCTION

As cannabis use rises among adults in the U.S., driving under the influence of cannabis represents a public health concern.

METHODS

In 2020, public-use data from the National Survey on Drug Use and Health were examined, using an analytic sample of 128,205 adults interviewed between 2016 and 2018. The annual prevalence of driving under the influence of cannabis was computed overall, by state, by demographic group, and among cannabis users. Demographic, psychosocial, and behavioral correlates of driving under the influence were tested by multivariate logistic regression.

RESULTS

The self-reported annual prevalence of driving under the influence of cannabis was 4.5% (95% CI=4.3, 4.6) among U.S. adults, ranging from 3.0% (Texas) to 8.4% (Oregon) in individual U.S. states. Among cannabis users, 29.5% (95% CI=28.6, 30.3) reported driving under the influence of cannabis; the predicted probabilities of driving under the influence of cannabis were highest for those with more frequent use, with daily cannabis users evidencing a 57% predicted probability. Among individuals with symptoms suggestive of a cannabis use disorder, the prevalence of driving under the influence of cannabis was 63.8% (95% CI=60.8, 66.6). Among cannabis users, those reporting driving under the influence of cannabis had higher odds of driving under the influence of other illicit substances, using other illicit drugs, taking part in illegal behavior, and suffering from mental distress, after adjusting for demographic characteristics and psychosocial/behavioral correlates.

CONCLUSIONS

Findings suggest that prevention efforts should focus on frequent and problem cannabis users and should include content related to other illicit drug use and other drug-impaired driving.

Modeling the influence of 0.03%, 0.05% and 0.08% blood alcohol concentrations on lane positioning and steering control of Indian drivers

OBJECTIVE

Alcohol-impairment of drivers has significant influence on road traffic safety; however, no experimental research has been conducted on the lateral driving control of Indian drivers. Therefore, the present study investigates the effects of different Blood Alcohol Concentration (BAC) levels (0%, 0.03%, 0.05% and 0.08%) and driver attributes on the lane positioning and steering control of Indian drivers.

METHOD

A driving simulator experiment was designed where 82 adult licensed drivers (62 males, 20 females) completed driving on the simulated urban arterial road environment under the influence of varying BACs. Lateral driving performance measures associated with lane positioning (lane position variability) and steering control of drivers (steering angle variability and steering reversal rates (SRR)) were analyzed.

RESULTS

The findings reported that lane position variability was significantly influenced only at 0.08% BAC (5.8% increment); no significant influence was observed at 0.03% and 0.05% BACs. Compared to 0% BAC, steering angle variability increased by 0.105 degrees or 15.7%, 0.142 degrees or 21.4%, and 0.176 degrees or 25.7% at 0.03%, 0.05% and 0.08% BACs respectively. No significant differences were observed between the sober-state driving and alcohol-impaired driving at 1^ο and 5^ο SRR. However, 10^ο SRR was found to be higher by 36%, 65% and 92% at 0.03%, 0.05% and 0.08% BACs compared to 0% BAC. Among the driver attributes, male drivers displayed higher impairment in lane positioning behavior as compared to female drivers. One-year increase in drivers' age reduced the lane position variability by 0.6%. Drivers who performed regular physical exercise were found to have better lateral control on the vehicle, as observed in their steering angle variability. Prior crash history had negative association with the steering reversal rates, indicating that drivers who have previous experience of crash involvement show better steering control than the drivers without any crash experience.

CONCLUSION

In conclusion, the outcomes of this study provide novel insights into the alcohol-impaired lateral vehicle control of Indian drivers which can assist in policy interventions aiming to reduce crashes with alcohol as a major crash causation factor.

Applications of brain imaging methods in driving behaviour research

Applications of neuroimaging methods have substantially contributed to the scientific understanding of human factors during driving by providing a deeper insight into the neuro-cognitive aspects of driver brain. This has been achieved by conducting simulated (and occasionally, field) driving experiments while collecting driver brain signals of various types. Here, this sector of studies is comprehensively reviewed at both macro and micro scales. At the macro scale, bibliometric aspects of these studies are analysed. At the micro scale, different themes of neuroimaging driving behaviour research are identified and the findings within each theme are synthesised. The surveyed literature has reported on applications of four major brain imaging methods. These include Functional Magnetic Resonance Imaging (fMRI), Electroencephalography (EEG), Functional Near-Infrared Spectroscopy (fNIRS) and Magnetoencephalography (MEG), with the first two being the most common methods in this domain. While collecting driver fMRI signal has been particularly instrumental in studying neural correlates of intoxicated driving (e.g. alcohol or cannabis) or distracted driving, the EEG method has been predominantly utilised in relation to the efforts aiming at development of automatic fatigue/drowsiness detection systems, a topic to which the literature on neuro-ergonomics of driving particularly has shown a spike of interest within the last few years. The survey also reveals that topics such as driver brain activity in semi-automated settings or neural activity of drivers with brain injuries or chronic neurological conditions have by contrast been investigated to a very limited extent. Potential topics in driving behaviour research are identified that could benefit from the adoption of neuroimaging methods in future studies. In terms of practicality, while fMRI and MEG experiments have proven rather invasive and technologically challenging for adoption in driving behaviour research, EEG and fNIRS applications have been more diverse. They have even been tested beyond simulated driving settings, in field driving experiments. Advantages and limitations of each of these four neuroimaging methods in the context of driving behaviour experiments are outlined in the paper.

Aggressive Driving Behaviours in Cannabis Users. The Influence of Consumer Characteristics

This study analysed dangerous driving behaviours in twenty young occasional cannabis users through objective and self-reported data, studying the relationship between the two aspects. Visual function was assessed in a baseline session and after smoking cannabis, as well as speed-related behaviour in a driving simulator. The participants responded to questionnaires on sociodemographic factors, their consumption profile, and the incidence of dangerous behaviours (Dula Dangerous Driving Index; DDDI). After cannabis use, the results revealed a significant deterioration in visual function. In terms of speed management, they showed significantly greater acceleration force in the two different sections of the route, and they drove significantly faster. Our correlations indicate that males and heavier users display more risky speed management. Likewise, the heavier cannabis users admitted to increased dangerous driving behaviour, and an accident in the preceding year was associated with a trend towards aggressive driving behaviour according to the DDDI questionnaire. The findings of this study suggest that cannabis users adopt dangerous behaviours when driving, despite the effect this drug has on certain important functions, such as vision. The results suggest a need for awareness-raising and information campaigns.

Young and under the influence: A systematic literature review of the impact of cannabis on the driving performance of youth

BACKGROUND

Young drivers ages 15-24 continue to constitute a high-risk population for fatal motor vehicle collisions (MVCs) compared to all other age groups. Driving under the influence of cannabis is an important contributor to the high rates of MVCs among youth. Understanding the specific impact of cannabis on the driving performance outcomes of young drivers can inform injury prevention, education, and intervention strategies.

OBJECTIVES

This systematic literature review (SLR) aims to determine the Class (I- highest to IV-lowest) of evidence and level of confidence (A-high to U-insufficient) in the effects of cannabis on the driving performance of young drivers.

METHODS

Registered in PROSPERO (#CRD42020180541), this SLR searched seven data bases and appraised the quality and confidence in the evidence using an established research methodology.

RESULTS

Class II evidence suggests that THC is likely to reduce mean speed, headway distance, and reaction time; and increase lane and steering wheel position variability among young drivers (Level B, moderate confidence).

CONCLUSIONS

This study shows that there is a moderate to low level of confidence on the impact of cannabis on the specific driving performance outcomes of young drivers. A need remains for Class I and II studies that focus on the specific effects on young drivers, distinguish between the biological and socially constructed variables of sex and gender, and includes larger and more representative samples.

Differential effects of stimulant versus opiate drugs on driving performance

BACKGROUND AND AIMS

Pharmacological differences among different drug classes influence human cognition, visual, and motor behavior in different ways. These differences impact driving safety, and therefore individuals who use stimulant and opioid drugs might experience different patterns in driving safety and impairment in driving performance. This study examined the effect of long-term use of stimulant drugs and of opiate drugs on driving performance, hazard perception, visual search skills and psychomotor skills related to driving.

METHODS

A total of 75 individuals, including 28 predominantly stimulant users, 22 predominantly opiate users and 25 healthy non-drug users, participated. Driving performance and psychomotor skills were assessed via a 15-minute drive in a simulator; hazard perception was assessed via a computerized task; and visual search skill was assessed by eye tracking.

RESULTS

ANOVA analyses indicate both stimulant and opiate users drove at higher speeds and experienced more crashes than the healthy non-drug users. Stimulant but not opiate users violated red light regulations more often than the healthy non-drug users. In the hazard perception task, stimulant drug users performed more poorly than both opioid drug users and healthy non-drug users. Specifically, they had lower saccade movement scores and higher average fixation times.

CONCLUSIONS

Results confirm that both stimulant drug users and opiate drug users show impaired driving performance compared to healthy non-drug users. Stimulant drug users possessed poorer hazard perception skills compared to the opiate users and the control group, perhaps as a result of cognitive deficits created by the drug use.

Cannabis, Impaired Driving, and Road Safety: An Overview of Key Questions and Issues

The road safety impact of cannabis has been a topic of much discussion and debate over the years. These discussions have been revitalized in recent years by initiatives in several jurisdictions to legalize non-medical cannabis. Canada became the second country to legalize non-medical cannabis use in October, 2018, preceded by Uruguay in December 2013. Road safety concerns were key issues in the Canadian government's deliberations on the issue. In this paper, we identify several key questions related to the impact of cannabis on road safety, and provide a consideration of the relevant literature on these questions. These questions cover several perspectives. From an epidemiological perspective, perhaps the central question is whether cannabis use contributes to the chances of being involved in a collision. The answer to this question has evolved in recent years as the ability to conduct the relevant studies has evolved. A related question is the extent to which cannabis plays an important role in road safety, and recent research has made progress in estimating the collisions, injuries, and deaths that may be attributed to cannabis use. Several questions relate to the behavioral and pharmacological effects of cannabis. One central question is whether cannabis affects driving skills in ways that can increase the chances of being involved in a collision. Another important question is whether the effects of the drug on the driving behavior of medical users is similar to, or different from, the effects on non-medical users and whether there are sex differences in the pharmacological and behavioral effects of cannabis. Other important questions are the impact of tolerance to the effects of cannabis on road safety as well as different routes of administration (e.g., edibles, vaped). It remains unclear if there is a dose-response relationship of cannabis to changes in driving. These and other key questions and issues are identified and discussed in this paper.

Sex differences in driving under the influence of cannabis: The role of medical and recreational cannabis use

BACKGROUND

Existing evidence suggest that cannabis may impair driving and is the most prevalent drug identified in drivers. Males exhibit an excess risk for driving under the influence of drugs or alcohol compared to females. We assessed sex differences in the association between the reason for cannabis use (medical, recreational, or both) and driving under the influence of cannabis (DUIC).

METHODS

A sample of 17,405 past 12-month cannabis users (18 + years old) were analyzed from the 2016-17 National Survey on Drug Use and Health. Multivariable logistic regression was used to assess the interaction of sex and reason for cannabis use on DUIC using predicted probabilities.

RESULTS

Among cannabis users in the sample, 88.1% used for recreational reasons, 7.8% used for medical reasons, and 4.1% used for medical and recreational reasons. The probability of DUIC was as low as 20% among female medical only users, and as high as 40% among male combined medical and recreational users. Females showed more similar probabilities of DUIC across reasons of use (range 20% to 25%s) than males (range 28% to 40%). The difference in the probability of DUIC between combined medical and recreational users and recreational only users was significantly greater among males than among females (Δ 0.1, p < 0.05).

CONCLUSIONS

The observed effects of sex and reasons for cannabis use on DUIC suggests a need for targeted educational interventions, particularly among males reporting combined medical and recreational marijuana use.

Impact of cannabis and low alcohol concentration on divided attention tasks during driving

OBJECTIVE

To assess divided-attention performance when driving under the influence of cannabis with and without alcohol. Three divided-attention tasks were performed following administration of placebo, cannabis, and/or alcohol.

METHODS

Healthy adult cannabis users participated in 6 sessions, receiving combinations of cannabis (placebo/low-THC/high-THC) and alcohol (placebo/active) in randomized order, separated by washout periods of ≥1 week. At 0.5 hours post-dosing, participants performed simulator drives in the University of Iowa National Advanced Driving Simulator (NADS-1), a full vehicle cab simulator with a 360° horizontal field of view and motion base that provides realistic feedback. Drives contained repeated instances of three tasks: a side-mirror task (reaction to a triangle appearing in the side-mirrors), an artist-search task (select a specified artist from a navigable menu on the vehicle's console), and a message-reading task (read aloud a message displayed on the console). Blood THC and breath alcohol concentration (BrAC) were interpolated using individual power curves from samples collected approximately 0.17, 0.42, 1.4, and 2.3 hours post-dose. Driving measures during tasks were compared to equal-duration control periods occurring just prior to the task. Performance shifts, task completion, and lane departures were modeled relative to blood THC and BrAC using mixed-effects regression models.

RESULTS

Each 1 µg/L increase in blood THC concentration predicted increased odds of failing to complete the artist-search task (OR: 1.05, 95% CI: 1.01-1.11, p = 0.046), increased odds of selecting at least one incorrect response (OR: 1.05, 95% CI: 1.00-1.09, p = 0.041), declines in speed during the side-mirror task (0.005 m/s, 95% CI: 0.001-0.009, p = 0.023), and longer lane departure durations during the artist-search task (0.74% of task-period, 95% CI: 0.12-1.36 p = 0.020). BrAC (approximately 0.05%) was not associated with task performance, though each 0.01 g/210 L increase predicted longer departure durations during the side-mirror task (1.41% of task-period, 95% CI: 0.08-2.76, p = 0.040) and increased standard deviation of lane position in the message-reading task (0.61 cm, 95% CI: 0.14-1.08, p = 0.011).

CONCLUSIONS

With increasing medical and legal cannabis use, understanding the impact of acute cannabis use on driving performance, including divided-attention, is essential. These data indicate that impaired divided-attention performance is a safety concern.

Direct and indirect effects of marijuana use on the risk of fatal 2-vehicle crash initiation

BACKGROUND

Marijuana and alcohol each play a significant role in fatal crash initiation. We decomposed the total effect of marijuana use in the presence or absence of alcohol on fatal crash initiation into direct and indirect effects.

METHODS

Pair-matched data on 5856 culpable drivers (initiators) and 5856 nonculpable drivers (noninitiators) involved in the same fatal 2-vehicle crashes recorded in the Fatality Analysis Reporting System between 2011 and 2016 were analyzed using the conditional logistic regression model and the unified mediation and interaction analysis framework.

RESULTS

Crash initiators were more likely than noninitiators to test positive for marijuana (16.1% vs. 9.2%, P < 0.001), alcohol (28.6% vs. 9.7%, P < 0.001) and both substances (6.3% vs. 1.6%, P < .0001). Adjusted odds ratios of fatal 2-vehicle crash initiation revealed a positive interaction on the additive scale between marijuana and alcohol. Of the total effect of marijuana use on fatal 2-vehicle crash initiation, 68.8% was attributable to the direct effect (51.5% to controlled direct effect and 17.3% to reference interaction effect with alcohol) and 31.2% to the indirect effect (7.8% to mediated interaction effect and 23.4% to pure indirect effect through alcohol).

CONCLUSION

Our results indicate that the increased odds of fatal 2-vehicle crash initiation associated with marijuana use is due mainly to the direct effect.

The effect of cannabidiol on simulated car driving performance: A randomised, double-blind, placebo-controlled, crossover, dose-ranging clinical trial protocol

OBJECTIVE

Interest in the use of cannabidiol (CBD) is increasing worldwide as its therapeutic effects are established and legal restrictions moderated. Unlike Δ9 -tetrahydrocannabinol (Δ9 -THC), CBD does not appear to cause cognitive or psychomotor impairment. However, further assessment of its effects on cognitively demanding day-to-day activities, such as driving, is warranted. Here, we describe a study investigating the effects of CBD on simulated driving and cognitive performance.

METHODS

Thirty healthy individuals will be recruited to participate in this randomised, double-blind, placebo-controlled crossover trial. Participants will complete four research sessions each involving two 30-min simulated driving performance tests completed 45 and 210 min following oral ingestion of placebo or 15, 300, or 1,500 mg CBD. Cognitive function and subjective drug effects will be measured, and blood and oral fluid sampled, at regular intervals. Oral fluid drug testing will be performed using the Securetec DrugWipe® 5S and Dräger DrugTest® 5000 devices to determine whether CBD increases the risk of "false-positive" roadside tests to Δ9 -THC. Noninferiority analyses will test the hypothesis that CBD is no more impairing than placebo.

CONCLUSION

This study will clarify the risks involved in driving following CBD use and assist in ensuring the safe use of CBD by drivers.

Association of Recreational Cannabis Laws in Colorado and Washington State With Changes in Traffic Fatalities, 2005-2017

IMPORTANCE

An important consequence of cannabis legalization is the potential increase in the number of cannabis-impaired drivers on roads, which may result in higher rates of traffic-related injuries and fatalities. To date, limited information about the effects of recreational cannabis laws (RCLs) on traffic fatalities is available.

OBJECTIVE

To estimate the extent to which the implementation of RCLs is associated with traffic fatalities in Colorado and Washington State.

DESIGN, SETTING, AND PARTICIPANTS

This ecological study used a synthetic control approach to examine the association between RCLs and changes in traffic fatalities in Colorado and Washington State in the post-RCL period (2014-2017). Traffic fatalities data were obtained from the Fatality Analysis Reporting System from January 1, 2005, to December 31, 2017. Data from Colorado and Washington State were compared with synthetic controls. Data were analyzed from January 1, 2005, to December 31, 2017.

MAIN OUTCOME(S) AND MEASURES

The primary outcome was the rate of traffic fatalities. Sensitivity analyses were performed (1) excluding neighboring states, (2) excluding states without medical cannabis laws (MCLs), and (3) using the enactment date of RCLs to define pre-RCL and post-RCL periods instead of the effective date.

RESULTS

Implementation of RCLs was associated with increases in traffic fatalities in Colorado but not in Washington State. The difference between Colorado and its synthetic control in the post-RCL period was 1.46 deaths per 1 billion vehicle miles traveled (VMT) per year (an estimated equivalent of 75 excess fatalities per year; probability = 0.047). The difference between Washington State and its synthetic control was 0.08 deaths per 1 billion VMT per year (probability = 0.674). Results were robust in most sensitivity analyses. The difference between Colorado and synthetic Colorado was 1.84 fatalities per 1 billion VMT per year (94 excess deaths per year; probability = 0.055) after excluding neighboring states and 2.16 fatalities per 1 billion VMT per year (111 excess deaths per year; probability = 0.063) after excluding states without MCLs. The effect was smaller when using the enactment date (24 excess deaths per year; probability = 0.116).

CONCLUSIONS AND RELEVANCE

This study found evidence of an increase in traffic fatalities after the implementation of RCLs in Colorado but not in Washington State. Differences in how RCLs were implemented (eg, density of recreational cannabis stores), out-of-state cannabis tourism, and local factors may explain the different results. These findings highlight the importance of RCLs as a factor that may increase traffic fatalities and call for the identification of policies and enforcement strategies that can help prevent unintended consequences of cannabis legalization.

Cannabis & ENT: State certification-An expanding yet unregulated system

OBJECTIVES

1) Ascertain the status of cannabis legalization by state, 2) Explore the process required to obtain cannabis credentials for both the patient and the physician, 3) Determine the level of interest of otolaryngologists in the medicinal cannabis, and 4) Explore possible research directions into efficacy and potential complications.

STUDY DESIGN

Descriptive study.

METHODS

Internet searches were conducted to identify each state's Medical Cannabis Program website. The qualifying conditions, list of approved-practitioners, process required for both practitioners and patients for approval were noted. Lists of approved practitioners were analyzed to determine the prevalence of board-certified otolaryngologists.

RESULTS

Of the 33 states that authorize medicinal cannabis, eight provide lists of approved-practitioners, six of which provide specialty information. A total of 24 Otolaryngologists can be found of the 5944 physicians on these six lists. All otolaryngologists were located in highly-populated metropolitan areas with a mean number of 29.9 years in practice. Significant variations exist between each state including legal definitions and qualifying conditions.

CONCLUSIONS

Lack of consistent regulation across the country drives uncertainty regarding the adoption of medicinal cannabis. Very few otolaryngologists in the country are registered to certify patients for medical cannabis. While the medicinal use of cannabis may currently have limited applications within otolaryngology, many areas that have yet to be explored.

Children and Youth Who Use Cannabis for Pain Relief: Benefits, Risks, and Perceptions

We provide up-to-date perspectives on the benefits and risks of medical cannabis for pain management in children and youth. To date, only two studies (a case report and a small observational study) have examined the effects of medical cannabis on pain in children and youth. No controlled trial has commented on long-term safety of medical cannabis. Findings from the recreational cannabis literature reveal significant potential short- and long-term risks of regular cannabis use, including impaired driving, depression, suicidality, psychosis, and tolerance. Despite this, many children and youth are self-medicating with cannabis, and perceive regular cannabis use to be safe. There is a need for better education and counselling of patients regarding the benefits and risks of medical cannabis use.

Electrochemical Oxidation of Δ9-Tetrahydrocannabinol: A Simple Strategy for Marijuana Detection

Recently, it has been estimated that nearly 200 million people use marijuana with growing usage being attributed to the legalization and decriminalization of the drug around the world. A concerning implication of increased marijuana use is the alarming number of individuals who report driving under the influence of the drug, which has prompted the development of detection technologies. An electrochemical-based detection technology, akin to how the alcohol breathalyzer functions, would provide an attractive solution to this growing societal problem. The first step toward this goal is to develop a reaction that converts Δ9-tetrahydrocannabinol (Δ9-THC), the primary psychoactive substance in marijuana, to a derivative with diagnostic spectroscopic changes. We report the development of a mild electrochemical method for the oxidation of Δ9-THC to its corresponding p-quinone isomer. The photophysical and electrochemical properties of the resultant quinone show a dramatic shift in comparison to Δ9-THC. This simple protocol provides the foundation for the development of an electrochemical-based marijuana breathalyzer.