Marijuana Use and Driving Under the Influence among Young Adults: A Socioecological Perspective on Risk Factors

Driving after substance use in Rhode Island adolescents: A cross-sectional analysis of surveillance data

OBJECTIVE

Existing literature on driving under the influence during adolescence is sparse, especially for driving after the use of non-medical prescription drugs (DAP). This study examines the prevalence of driving after use of alcohol (DAA), cannabis (DAC), and DAP, and examines the role of several potential risk and protective factors.

METHODS

This was a secondary analysis of the 2022 Rhode Island Study Survey, a cross-sectional survey of middle and high school students. Separate multivariable regressions were conducted for each outcome among lifetime users for each substance, controlling for current substance use, individual-, perceived parental-, and perceived friend-substance use risk perception, age, sexual/gender minority (SGM) status, race, ethnicity, school level, and town poverty level.

RESULTS

Among lifetime users of alcohol (n = 3849), cannabis (n = 2289), and non-medical prescription drugs (n = 611), the prevalence of DAA, DAC, and DAP was 4.9, 14.3, and 16.9%, respectively. Current substance use, high individual risk perception, being nonwhite, and being Hispanic were risk factors for DAA while perceiving parent's risk perception as negative and being heterosexual cisgender-female were protective. Current substance use, negative individual risk perception, and being nonwhite were risk factors for DAC while perceiving parent's risk perception as negative and being in high school were protective. Current substance use and older age were risk factors for DAP while perceiving parent's risk perception as negative and perceiving friend's risk perception as negative were protective.

CONCLUSIONS

Driving under the influence is a concern among adolescent substance users. Current substance use and perceived parental risk perception as negative are common risks and protective factors, respectively. Findings suggest substance-specific, heterogeneous interventions are needed. For example, interventions focusing on peer perceptions are most relevant for DAP, while shifting personal perceptions of harm are most relevant for DAC.

Risk factors associated with driving after marijuana use among West Virginia college students during the COVID-19 pandemic

OBJECTIVES

The purpose of this study was to assess sociodemographic and behavioral risk factors associated with driving after marijuana use (DAMU) among West Virginia college students.

METHODS

Participants were recruited from West Virginia University between September and November 2022. The study sample was restricted to students who were ≥18 years of age; reported recently driving; possessed a current, valid driver's license from any US state; and were enrolled for at least one credit hour in the Fall 2022 semester.

RESULTS

Among respondents (N = 772), 28.9% reported DAMU. Students who had a GPA of B (adjusted odds ratio [AOR]: 2.17, 95% confidence interval [CI]: 1.06-4.42), smoked or ingested marijuana in the past year (AOR: 26.51, 95% CI: 10.27-68.39), drove after drinking (AOR: 2.38, 95% CI: 1.18-4.79), and used both marijuana and alcohol concurrently and then drove (AOR: 10.39, 95% CI: 2.32-46.54) associated with DAMU. Individuals who felt the behavior was somewhat dangerous or not dangerous or thought their peers approved of DAMU showed significant associations with DAMU.

CONCLUSIONS

As DAMU was prevalent, future interventions that raise awareness of the danger and potential consequences of DAMU may be needed to reduce this risky behavior on college campuses.

Cannabis Retailer Communication About Cannabis Products, Health Benefits, and Risks: A Mystery Shopper Study of Licensed Retailers in Five U.S. Cities

OBJECTIVE

As the U.S. cannabis market expands, surveillance of retailer practices, especially product health claims and risks, is crucial to protect consumers. In this study, mystery shoppers (i.e., staff not explicitly identified as researchers) examined retail personnel communication regarding product recommendations, health benefits, safety, and/or risks among U.S. cannabis retailers.

METHOD

In Summer 2022, mystery shoppers audited 140 licensed cannabis retailers in 5 cities in states with established nonmedical (i.e., recreational) cannabis sales and diverse regulations (Denver, Colorado; Seattle, Washington; Portland, Oregon; Las Vegas, Nevada; Los Angeles, California). Descriptive and bivariate analyses characterized retail personnel communication overall and across cities.

RESULTS

Common product recommendations for new users included edibles, pre-rolled joints, and bud/flower, and 8.6% offered free/inexpensive ways to sample products. Although Colorado, Washington, and Oregon explicitly prohibited health claims in advertising or labels, more than 90% of retailers there endorsed use for anxiety, insomnia, and/or pain. Whereas 54.3% endorsed use for pregnancy-related nausea (least common in Denver, 23.3%; most common in Seattle, 76.7%), 26.4% warned against use during pregnancy (most frequently in Denver, 46.7%; least frequently in Seattle and Portland, 13.3%). Overall, 52.1% warned against driving after use (most frequently in Denver, 80.0%; least frequently in Las Vegas, 20.0%). Almost all (≥90%) sold cannabidiol (CBD) products and endorsed their health benefits and safety, but few (<10%) sold or endorsed delta-8 tetrahydrocannabinol (THC), etc. (all of which were in Los Angeles).

CONCLUSIONS

Ongoing cannabis retail surveillance, particularly using protocols assessing factors outside those visibly observable, is needed to inform regulatory and enforcement efforts, especially related to health claims.

Health, safety, and socioeconomic impacts of cannabis liberalization laws: An evidence and gap map

Background

Globally, cannabis laws and regulations are rapidly changing. Countries are increasingly permitting access to cannabis under various decriminalization, medicalization, and legalization laws. With strong economic, public health, and social justice incentives driving these domestic cannabis policy reforms, liberalization trends are bound to continue. However, despite a large and growing body of interdisciplinary research addressing the policy-relevant health, safety, and socioeconomic consequences of cannabis liberalization, there is a lack of robust primary and systematic research that comprehensively investigates the consequences of these reforms.

Objectives

This evidence and gap map (EGM) summarizes the empirical evidence on cannabis liberalization policies. Primary objectives were to develop a conceptual framework linking cannabis liberalization policies to relevant outcomes, descriptively summarize the empirical evidence, and identify areas of evidence concentration and gaps.

Search Methods

We comprehensively searched for eligible English-language empirical studies published across 23 academic databases and 11 gray literature sources through August 2020. Additions to the pool of potentially eligible studies from supplemental sources were made through November 2020.

Selection Criteria

The conceptual framework for this EGM draws upon a legal epidemiological perspective highlighting the causal effects of law and policy on population-level outcomes. Eligible interventions include policies that create or expand access to a legal or decriminalized supply of cannabis: comprehensive medical cannabis laws (MCLs), limited medical cannabidiol laws (CBDLs), recreational cannabis laws (RCLs), industrial hemp laws (IHLs), and decriminalization of cultivations laws (DCLs). Eligible outcomes include intermediate responses (i.e., attitudes/behaviors and markets/environments) and longer-term consequences (health, safety, and socioeconomic outcomes) of these laws.

Data Collection and Analysis

Both dual screening and dual data extraction were performed with third person deconfliction. Primary studies were appraised using the Maryland Scientific Methods Scale and systematic reviews were assessed using AMSTAR 2.

Main Results

The EGM includes 447 studies, comprising 438 primary studies and nine systematic reviews. Most research derives from the United States, with little research from other countries. By far, most cannabis liberalization research focuses on the effects of MCLs and RCLs. Studies targeting other laws-including CBDLs, IHLs, and DCLs-are relatively rare. Of the 113 distinct outcomes we documented, cannabis use was the single most frequently investigated. More than half these outcomes were addressed by three or fewer studies, highlighting substantial evidence gaps in the literature. The systematic evidence base is relatively small, comprising just seven completed reviews on cannabis use (3), opioid-related harms (3), and alcohol-related outcomes (1). Moreover, we have limited confidence in the reviews, as five were appraised as minimal quality and two as low quality.

Authors’ Conclusions

More primary and systematic research is needed to better understand the effects of cannabis liberalization laws on longer-term-and arguably more salient-health, safety, and socioeconomic outcomes. Since most research concerns MCLs and RCLs, there is a critical need for research on the societal impacts of industrial hemp production, medical CBD products, and decriminalized cannabis cultivation. Future research should also prioritize understanding the heterogeneous effects of these laws given differences in specific provisions and implementation across jurisdictions.

What contributes to drug driving? An exploratory investigation into the influence of problematic substance use, roadside testing and alternative transport options

Despite a strong reliance on enforcement approaches to prevent drug driving in Australia, this behaviour is still prevalent. The objective of this study was to investigate the influence of problematic drug use (i.e., showing indications of addiction), exposure to roadside drug testing, the use of detection avoidance strategies, and perceptions relating to alternative transport options on drug driving among illicit drug users. A total of 1,541 licensed drivers from the states of Queensland, New South Wales, and Victoria completed an online survey. The survey collected demographic and problematic substance use information, as well as items assessing drug driving behaviour. Cannabis was reported to be the most commonly used drug (36.0%); the most common drug of problematic use (27.9%), and the drug most often taken prior to driving (43.5%). Observing police operating Roadside Drug Tests (RDT) was more common among the participants than being tested by RDT (35.7% vs 23%). The results indicated a significant association between being a drug driver and observing or being tested by RDT. The drug drivers were significantly more likely to report using a range of strategies to avoid police detection than the non-drug drivers. Similarly, the drug drivers reported that it was more difficult for them to use various alternative transport options than the non-drug drivers. Decision tree analyses found that significant predictors of self-reported drug driving were problematic drug use, holding a provisional or probationary licence, earning a low- or middle-income, and using detection avoidance strategies like remaining watchful for police vehicles and taking back streets. The findings of this study suggest that ongoing improvements to drug driving enforcement will need to be complemented by health-based approaches designed to reduce drug abuse and dependence, and improvements to public transport, in order to achieve a sustainable reduction in drug driving.

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.

The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities

In the U.S., an increasing number of states are legalizing regulated commercial markets for recreational cannabis, which allows private industry to produce, distribute, and sell marijuana to those 21 and older. The health impacts of these markets are not fully understood. Preliminary evidence suggests recreational markets may be associated with increased use among adults, which indicates there may be downstream health impacts on outcomes related to cannabis use. Three causes of death that are linked to cannabis use are motor vehicle accidents, suicide, and opioid overdose. Drawing on data from U.S. death certificates from 2009 to 2019, we conducted a difference-in-differences analysis to estimate the impact of recreational markets on fatalities from motor vehicle accidents, suicide, and opioid overdose in seven states: Colorado, Washington, Oregon, Alaska, Nevada, California, and Massachusetts. States with comprehensive medical cannabis programs with similar pre-trends in deaths were used as comparisons. For each outcome, a pooled estimate was generated with a meta-analysis using random effects models. The results revealed substantial increases in crash fatalities in Colorado, Oregon, Alaska, and California of 16%, 22%, 20%, and 14%, respectively. Based on estimates from all seven states, recreational markets were associated with a 10% increase in motor vehicle accident deaths, on average. This study found no evidence that recreational markets impacted suicides. Most states saw a relative reduction in opioid overdose death that ranged between 3 and 28%. On average, recreational markets were associated with an 11% reduction in opioid overdose fatalities.

Self-reported impacts of recreational and medicinal cannabis use on driving ability and amount of wait time before driving

OBJECTIVE

Past research indicates that driving after cannabis use is relatively common. However, not all cannabis users are equally likely to drive after use; frequent cannabis users and frequent drivers are most at risk. It has been suggested that this is due to a perceived lack of impact of cannabis on driving ability.

METHODS

The current study sought to better understand the motivation to drive after recent cannabis use. A survey was used to examine the self-reported impact of cannabis use on driving ability and, further, the amount of time cannabis users wait before driving after use. A total of 562 participants were recruited. Of these, 424 completed the survey and were included for analysis. Purposive sampling was used to screen for cannabis users who were over the age of 18 and residents of Connecticut.

RESULTS

Cannabis use frequency was found to predict the self-reported impact of both recreational and medicinal cannabis on driving ability, such that more frequent cannabis users reported less impairment. Additionally, cannabis use frequency was predictive of wait time before driving, where more frequent users reported waiting less time before driving after cannabis use. A plurality of participants reported not waiting at all before driving after using cannabis. Notably, the self-reported impact of cannabis on driving ability was not associated with wait time before driving.

CONCLUSIONS

Cannabis users may not wait before driving even if they think it has a negative impact on their driving ability. Other factors that potentially impact driving after using cannabis warrant investigation.

The Impact of Cannabis Decriminalization and Legalization on Road Safety Outcomes: A Systematic Review

INTRODUCTION

There is substantial debate concerning the impact of cannabis decriminalization and legalization on road safety outcomes.

METHODS

Seven databases were systematically searched: Embase, MEDLINE, and PsycINFO through Ovid as well as Web of Science Core Collection, SafetyLit, Criminal Justice Database (ProQuest), and Transport Research International Documentation (from inception to June 16, 2021). Eligible primary studies examined group-level cannabis decriminalization or legalization and a road safety outcome in any population.

RESULTS

A total of 65 reports of 64 observational studies were eligible, including 39 that applied a quasi-experimental design. Studies examined recreational cannabis legalization (n=50), medical cannabis legalization (n=22), and cannabis decriminalization (n=5). All studies except 1 used data from the U.S. or Canada. Studies found mixed impacts of legalization on attitudes, beliefs, and self-reported driving under the influence. Medical legalization, recreational legalization, and decriminalization were associated with increases in positive cannabis tests among drivers. Few studies examined impacts on alcohol or other drug use, although findings suggested a decrease in positive alcohol tests among drivers associated with medical legalization. Medical legalization was associated with reductions in fatal motor-vehicle collisions, whereas recreational legalization was conversely associated with increases in fatal collisions.

DISCUSSION

Increased cannabis positivity may reflect changes in cannabis use; however, it does not in itself indicate increased impaired driving. Subgroups impacted by medical and recreational legalization, respectively, likely explain opposing findings for fatal collisions. More research is needed concerning cannabis decriminalization; the impacts of decriminalization and legalization on nonfatal injuries, alcohol and other drugs; and the mechanisms by which legalization impacts road safety outcomes.

A study of self-reported personal cannabis use and state legal status and associations with engagement in and perceptions of cannabis-impaired driving

Objective: The objectives of the current study were to (1) characterize predictors of perceived risk of driving within 2 h of cannabis use and driving after cannabis use in a sample of adults who have used cannabis in the past year and (2) determine whether the influence of these predictors vary by state legalizations status.Methods: Data for this study were from online surveys. Study participants from Colorado, Iowa, and Illinois were included if they reported being between 25 and 40 years old and had a history of cannabis use. Outcome variables included (1) days of cannabis use per month, (2) reported driving within 2 h of cannabis use (vs. not driving within 2 h as reference), (3) proportion of driving after cannabis use days per month (days of driving a car within 2 h of cannabis use per month/days of cannabis use per month), and (4) perception of safety of driving after cannabis use. Potential predictors included age of first use of cannabis, gender, education status, and state of residence. The SAS GLMSELECT Procedure was used for the analysis.Results: Increased age of first use of cannabis was associated with decreased days of cannabis use per month (B = -0.51 days/month per year), a reduction in the proportion of driving after cannabis use days per month (B = -0.02 per month), and decreased perception of safety of driving after cannabis use (B = -0.06 per year). Female gender was also associated with less use (B = -2.3 days per month), a lower proportion of driving following use (B = -0.06 days driving/days used), and decreased perception of safety (B = -0.29). In addition, residents of Colorado reported using the most days, had the highest likelihood of driving within 2 h of use, and had the most positive perceptions of being able to safely drive after cannabis use.Conclusions: The delay in onset of cannabis use may mitigate its use among adults and driving after cannabis use. This has important implications for driver safety. Intervention programs for reducing cannabis's effects on driving should focus on individuals with early onset of use, male drivers, and drivers in states where cannabis for adult recreational use is legalized.

An examination of the acquired preparedness model among college student marijuana users

ObjectiveTo examine the Acquired Preparedness Model using a behavioral impulsivity facet and positive marijuana expectancies to examine direct and indirect effects on marijuana use and related problems. Participants: 250 college students (61.7% female, 54% white) recruited from a southeastern university. Methods: Participants completed an online survey of delay reward discounting, marijuana expectancies, consideration of future consequences, and marijuana-related outcomes. Results: Delay reward discounting and consideration of future consequences related to marijuana-related problems, but not marijuana use. However, positive marijuana expectancies did not mediate the relation between impulsivity and marijuana outcomes. Conclusions: These results emphasize delay reward discounting and consideration of future consequences as important factors associated with marijuana-related problems. Interventions aimed at decreasing delay reward discounting and augmenting future orientation may be effective in college students who report light to moderate marijuana use. Future studies would benefit from longitudinal study designs using multiple impulsivity measures among light and heavy users.

Daily level predictors of impaired driving behaviors in young adults: Protocol design for utilizing daily assessments

Background

Motor vehicle crashes remain a leading cause of death among young adults (ages 18–25) in the United States. Many drivers implicated in these crashes are under the influence of alcohol, cannabis, or the simultaneous use of alcohol and cannabis. Extremely limited research has assessed impaired driving behaviors and their predictors at the daily level. Perceived norms and motives to use substances have empirical support suggesting they may impact impaired driving-related behavior. Novel approaches to assess these associations at the daily level are needed and may inform future intervention and prevention programs.

Objective

The goal of the current study is to utilize electronic daily assessments to assess driving under the influence of alcohol, cannabis, or simultaneous use and riding with a driver impaired by these substances to assess variability and predictors of these impaired driving-related behaviors at the daily level. This present manuscript details a protocol, measures, and a plan of analyses to assess how within-person differences in perceived norms and motives to use are associated with the likelihood of engaging in impaired driving-related behaviors.

Methods

Participants include young adults in Washington State who report simultaneous use in the past month and either driving under the influence of alcohol, cannabis, or simultaneous use, or riding with a driver under the influence of both substances in the past 6 months. Individuals who verify their identity and meet eligibility requirements will complete a baseline assessment after which they will be scheduled for training on the daily assessment procedure via Zoom. Next, they will be invited to complete daily surveys on Thursday, Friday, Saturday, and Sunday every other week for 6 months and a 6-month follow up assessment. Analyses will utilize multilevel models with days nested within individuals.

Results

The study is currently recruiting participants. A total of 192 participants have been recruited and 100 have completed the study protocol. Data collection is expected to be completed in Fall 2022.

Conclusions

This study utilizes a novel design to assess impaired driving and predictors at the daily level among young adults at high risk of impaired driving-related behaviors. Findings will provide unique data that will shape the knowledge base in the field of social science and public health substance use research and that may be helpful for future prevention and intervention efforts on impaired driving.

Drivers and Passengers in Vehicles Driven Under the Influence of Alcohol or Marijuana: Behavior Profiles and Risk Factors Among Young Adults in a Longitudinal Study

OBJECTIVE

Little research has examined psychosocial influences differentially associated with driving under the influence of alcohol and marijuana (DUIA/DUIM) or of being a passenger in a vehicle driven by someone under the influence of alcohol or marijuana (PVA/PVM).

METHOD

Using 2019 survey data among 2,375 young adults (M age = 24.66, 57.7% female, 51.2% in states with legal marijuana retail) in a longitudinal study examining vaping retail, we conducted latent class analysis (LCA) to identify classes of DUI-related behaviors and multinomial logistic regression to identify correlates of classes (e.g., individual, interpersonal, policy related).

RESULTS

A total of 22.6% reported past-month DUIA, 24.1% DUIM, 29.7% PVA, and 27.7% PVM. Of those reporting DUIA, 41.4% reported DUIM, 71.8% PVA, and 40.7% PVM. Of those reporting DUIM, 47.7% reported DUIA, 49.6% PVA, and 83.8% PVM. LCA indicated four classes: alcohol and marijuana risk takers (5.9%), all of whom reported DUIA and DUIM, 81.2% PVA, and 89.2% PVM; marijuana risk takers (14.2%), 45.1% DUIM, 100% PVM, 7.8% PVA, and 0% DUIA; alcohol risk takers (24.1%), 40.1% DUIA, 98.6% PVA, 2.6% DUIM, and 33.8% PVM; and low risk takers (55.8%), 8.7% DUIA, 4.5% DUIM, and 0% PVA/PVM. Relative to the other classes, alcohol and marijuana risk takers were more likely male, heterosexual, and White, and alcohol and marijuana risk takers reported greater depressive symptoms. Influences of parent/peer alcohol versus marijuana use were specific to the respective DUI risk behaviors. No differences emerged for legal marijuana retail.

CONCLUSIONS

Findings regarding those at particular risk, social influences, and situations under which DUI-related behaviors occur should inform future interventions and research.

Drivers and Passengers in Vehicles Driven Under the Influence of Alcohol or Marijuana: Behavior Profiles and Risk Factors Among Young Adults in a Longitudinal Study

OBJECTIVE

Little research has examined psychosocial influences differentially associated with driving under the influence of alcohol and marijuana (DUIA/DUIM) or of being a passenger in a vehicle driven by someone under the influence of alcohol or marijuana (PVA/PVM).

METHOD

Using 2019 survey data among 2,375 young adults (M age = 24.66, 57.7% female, 51.2% in states with legal marijuana retail) in a longitudinal study examining vaping retail, we conducted latent class analysis (LCA) to identify classes of DUI-related behaviors and multinomial logistic regression to identify correlates of classes (e.g., individual, interpersonal, policy related).

RESULTS

A total of 22.6% reported past-month DUIA, 24.1% DUIM, 29.7% PVA, and 27.7% PVM. Of those reporting DUIA, 41.4% reported DUIM, 71.8% PVA, and 40.7% PVM. Of those reporting DUIM, 47.7% reported DUIA, 49.6% PVA, and 83.8% PVM. LCA indicated four classes: alcohol and marijuana risk takers (5.9%), all of whom reported DUIA and DUIM, 81.2% PVA, and 89.2% PVM; marijuana risk takers (14.2%), 45.1% DUIM, 100% PVM, 7.8% PVA, and 0% DUIA; alcohol risk takers (24.1%), 40.1% DUIA, 98.6% PVA, 2.6% DUIM, and 33.8% PVM; and low risk takers (55.8%), 8.7% DUIA, 4.5% DUIM, and 0% PVA/PVM. Relative to the other classes, alcohol and marijuana risk takers were more likely male, heterosexual, and White, and alcohol and marijuana risk takers reported greater depressive symptoms. Influences of parent/peer alcohol versus marijuana use were specific to the respective DUI risk behaviors. No differences emerged for legal marijuana retail.

CONCLUSIONS

Findings regarding those at particular risk, social influences, and situations under which DUI-related behaviors occur should inform future interventions and research.

A systematic review of factors associated with illegal drug driving

Drug driving is a serious problem worldwide that can increase the risk of road crashes. This systematic review seeks to identify factors associated with drug driving (i.e., driving after consuming drugs other than alcohol) to highlight gaps in existing knowledge and inform the design of more effective countermeasures. A search of the literature was conducted for the period January 1, 2005 to July 31, 2021 using six different databases. The search protocol followed PRISMA guidelines and was registered in PROSPERO (#CRD42021234616). Studies that met inclusion criteria compared drug drivers with either non-drug drivers, alcohol-only drivers or drug drivers from an earlier time period, to identify factors specifically associated with drug driving, rather than common to all drivers. Two hundred and nineteen publications met the inclusion criteria and were included within the review. Based on the findings, a logic model was developed that presents the factors associated with drug driving. Various sociodemographic, psychosocial and legal factors emerged as the main factors associated with illegal drug driving. At the sociodemographic and psychological levels, drug drivers were more likely to be single, young males who often drive after using cannabis and who score high on sensation-seeking and impulsivity scales. The key social factor found to be associated with drug driving was peer acceptance/disapproval of the behaviour. At the legal level, the review suggested that the effectiveness of current enforcement approaches to drug driving vary among jurisdictions around the world due to differences in the level of perceived certainty of apprehension and the chances of punishment avoidance. Future research into the anticipated and actual rewards for drug driving is needed to inform the development of more effective countermeasures.

Typologies of Canadian young adults who drive after cannabis use: A two-step cluster analysis

Young adults that drive after cannabis use (DACU) may not share all the same characteristics. This study aimed to identify typologies of Canadians who engage in DACU. About 910 cannabis users with a driver's license (17-35 years old) who have engaged in DACU completed an online questionnaire. Two-step cluster analysis identified four subgroups, based on driving-related behaviors, cannabis use and related problems, and psychological distress. Complementary comparative analysis among the identified subgroups was performed as external validation. The identified subgroups were: (1) frequent cannabis users who regularly DACU; (2) individuals with generalized deviance with diverse risky road behaviors and high levels of psychological distress; (3) alcohol and drug-impaired drivers who were also heavy frequent drinkers; and (4) well-adjusted youths with mild depressive-anxious symptoms. Individuals who engaged in DACU were not a homogenous group. When required, prevention and treatment need to be tailored according to the different profiles.

Driving After Cannabis Use Among Young Adults in Michigan

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

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

Risk Factors Associated With Driving After Cannabis Use Among Canadian Young Adults

This study identifid the most prominent risk factors associated with driving after cannabis use (DACU). 1,126 Canadian drivers (17–35 years old) who have used cannabis in the past 12 months completed an online questionnaire about sociodemographic information, substance use habits, cannabis effect expectancies, driving behaviours and peers’ behaviours and attitudes concerning DACU. A hierarchical logistic regression allowed identifying variables that were associated with DACU. Income (CA$30,000–CA$69,000), weekly-to-daily cannabis use, higher level of cannabis-related problems, expectation that cannabis facilitates social interactions, drunk driving, belief that DACU is safe, general risky driving behaviours, having a few friends who had DACU and injunctive norms predicted past 12-month DACU. Older age, holding negative expectations concerning cannabis, driving aggressively and perceived accessibility of public transportation decreased the probability of DACU. With restricted resources, programmes will be more efficient by targeting Canadian young adults most inclined to DACU by focussing on these risk factors.

Correlates of driving after cannabis use in high school students

Driving under the influence of cannabis is a growing public health concern among young people. This study assessed the prevalence of cannabis-impaired driving and its related sociodemographic, psychological, and knowledge-based correlates among Canadian adolescents. The sample for this study were drawn from the 2017 Ontario Student Health and Drug Use Survey (OSDUHS), consisting of high school students with valid driver's licenses (mean age = 16.8, SD = 0.71) who were asked about their driving behaviors, drug use, and attitudes regarding cannabis use (N = 1161). A multivariable logistic regression model was performed to determine the strongest correlates of driving after cannabis use. The prevalence of past-year driving within an hour of cannabis use was 10.3% (95% CI: 7.8,13.5). In the final multivariable model, probable cannabis dependence (OR = 12.7, 95%CI: 3.4,47.7), low perceived risk of cannabis use (OR = 5.3, 95%CI: 2.5,11.1), pro-legalization attitudes, (OR = 4.3, 95%CI: 2.0,9.1) and male gender (OR = 2.6, 95%CI: 1.5,4.5) were significantly associated with driving under the influence of cannabis. Other correlates of driving after cannabis user were risky driving behaviors, including past-year texting and driving and driving after alcohol use. There are various correlates of driving under the influence of cannabis, including attitudes related to cannabis which may be amenable to intervention. Future efforts should continue to monitor the prevalence of cannabis-impaired driving in this population and determine whether changes in students' attitudes surrounding cannabis are linked to behavioural changes.

Interventions to Prevent Drugged Driving: A Systematic Review

CONTEXT

Literature suggests that cannabis legalization may increase fatal motor vehicle collisions. However, evidence on the effectiveness of interventions to prevent drugged driving is limited.

EVIDENCE ACQUISITION

MEDLINE, PsycINFO, Web of Science, Embase, SafetyLit, Criminal Justice Database, Transport Research International Documentation, bibliographies, and relevant gray literature were searched systematically through May 2020. Randomized and nonrandomized studies of preventive interventions measuring drugged driving outcomes were included. Evidence certainty was judged per Grading of Recommendations Assessment, Development, and Evaluation guidelines to designate quality ratings from very low to high.

EVIDENCE SYNTHESIS

The search identified 11 RCTs and 17 nonrandomized studies conducted predominantly among youth (aged 15-25 years; n=33,711 of 37,117 active research participants). In the public, cannabis packaging with health warnings increases the knowledge about drugged driving effects (high certainty); roadside drug testing can reduce drugged driving among cannabis users (moderate certainty); media campaigns may increase deterrent attitudes and knowledge (low certainty); and state sanctions, including traffic offense criminalization, license withdrawal, and per se drugged driving laws, may have little or no effect on drug-related fatalities or injuries (very low-low certainty). For youth or previous offenders, motivational interviewing can prevent drugged driving and driver education programs can increase knowledge (moderate certainty), whereas drug abuse prevention, substance abuse treatment, and driver rehabilitation may prevent drugged driving (very low certainty).

CONCLUSIONS

Overall, there is evidence to support the interventions that may improve drugged driving knowledge, attitudes, and behaviors. However, the impact of such interventions on measures of drugged driving-related morbidity and mortality is uncertain. Further research is urgently required to address these gaps in knowledge.

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.

Changes in Medical Cannabis Patient Status before and after Cannabis Legalization in California: Associations with Cannabis and Other Drug Use

It is unknown how patterns of cannabis and other drug use changed among young adult cannabis users as they became, exited or stayed medical cannabis patients (MCPs) after California legalized cannabis for adult use in 2016. A cohort of 18-26 year-old cannabis users was recruited in Los Angeles in 2014-15 (64.8% male; 44.1% Hispanic/Latinx). Based on wave 1 (pre-legalization) and wave 4 (post-legalization) MCP status, four transition groups emerged: MCP, Into MCP, Out of MCP and NPU (non-patient user). Relationships between self-reported medical cannabis use, transition group membership, and cannabis/other drug use outcomes were examined. Changes in cannabis practices were consistent with changes in MCP status. Cannabis days, concentrate use, self-reported medical cannabis use and driving under influence of cannabis were highest among MCP, increased for Into MCP, and decreased for Out of MCP in wave 4. A majority of drug use outcomes decreased significantly by wave 4. Self-reported medical cannabis use was associated with more frequent cannabis use but less problematic cannabis and other drug use. Future studies should continue to monitor the impact of policies that legalize cannabis for medical or recreational use, and medical motivations for cannabis use on young adults' cannabis and other drug use.

Cannabis use and driving under the influence: Behaviors and attitudes by state-level legal sale of recreational cannabis

BACKGROUND

As states continue to legalize the sale of recreational cannabis, there is a need to study attitudes and behaviors regarding driving after cannabis use. The purpose of this study was to describe US adults' attitudes and behaviors regarding driving after cannabis use by state-level legal sale of recreational cannabis, and to determine whether these associations differ by frequency of cannabis use.

METHODS

Data were collected from a national sample of 17,112 adults in the United States. Weighted adjusted prevalence ratios and 95% confidence intervals were used to compare the prevalence of behaviors and attitudes by state-level legal sale of recreational cannabis. Analyses were repeated among recent cannabis users, stratifying by cannabis use status.

RESULTS

Driving after cannabis use was more prevalent in legal cannabis sales states; however, so were potentially protective attitudes related to cannabis use and driving. After stratifying by frequency of use, daily/almost daily, weekly/monthly, and past 12-month users from states with legal recreational cannabis sales had significantly lower prevalence of driving after cannabis use and higher prevalence of protective attitudes compared to those from states without legal recreational sales. Risk perceptions were lower for cannabis than alcohol.

CONCLUSIONS

Public health messaging campaigns to reduce driving and riding after cannabis use and to improve attitudes regarding driving after cannabis use are warranted across all U.S. states, regardless of legalization status.

Social media recruitment for mental health research: A systematic review

BACKGROUND

Social media holds exciting promise for advancing mental health research recruitment, however, the extent and efficacy to which these platforms are currently in use are underexplored.

OBJECTIVE

A systematic review was conducted to characterize the current use and efficacy of social media in recruiting participants for mental health research.

METHOD

A literature review was performed using MEDLINE, EMBASE, and PsychINFO. Only non-duplicative manuscripts written in the English language and published between 1/1/2004-3/31/2019 were selected for further screening. Data extracted included study type and design, participant inclusion criteria, social media platform, advertising strategy, final recruited sample size, recruitment location, year, monetary incentives, comparison to other recruitment methods if performed, and final cost per participant.

RESULTS

A total of 176 unique studies that used social media for mental health research recruitment were reviewed. The majority of studies were cross-sectional (62.5%) in design and recruited adults. Facebook was overwhelmingly the recruitment platform of choice (92.6%), with the use of paid advertisements being the predominant strategy (60.8%). Of the reviewed studies, substance abuse (43.8%) and mood disorders (15.3%) were the primary subjects of investigation. In 68.3% of studies, social media recruitment performed as well as or better than traditional recruitment methods in the number and cost of final enrolled participants. The majority of studies used Facebook for recruitment at a median cost per final recruited study participant of $19.47. In 55.6% of the studies, social media recruitment was the more cost-effective recruitment method when compared to traditional methods (e.g., referrals, mailing).

CONCLUSION

Social media appears to be an effective and economical recruitment tool for mental health research. The platform raises methodological and privacy concerns not covered in current research regulations that warrant additional consideration.

Perceived safety of cannabis intoxication predicts frequency of driving while intoxicated

Driving under the influence of cannabis (DUIC) is a public health concern, and data are needed to develop screening and prevention tools. Measuring the level of intoxication that cannabis users perceive as safe for driving could help stratify DUIC risk. This study tested whether intoxication levels perceived as safe for driving predicted past-month DUIC frequency. Online survey data were collected in 2017 from a national sample of n = 3010 past-month cannabis users with lifetime DUIC (age 18+). Respondents indicated past-month DUIC frequency, typical cannabis intoxication level (1-10 scale), and cannabis intoxication level perceived as safe for driving (0-10 scale). Approximately 24%, 38%, 13%, and 24% of respondents engaged in DUIC on 0, 1-9, 10-19, and 20-30 days respectively in the past month. Among these four DUIC frequency groups, median typical intoxication varied little (5-6), but median intoxication perceived as safe for driving varied widely (3-8). Higher intoxication levels perceived as safe for driving corresponded to frequent DUIC (Spearman's rho: 0.46). For each unit increase in intoxication level perceived as safe for driving, the odds of past-month DUIC increased 18% to 68% (multinomial logistic regression odds ratio - MOR1-9 days: 1.18, 95% CI: 1.13-1.23; MOR10-19 days: 1.40, 95% CI: 1.30-1.50; MOR20-30 days: 1.68, 95% CI: 1.57-1.80). In this targeted sample of past-month cannabis users, DUIC frequency varied widely, but daily/near-daily DUIC was common (24%). Measuring intoxication levels perceived as safe for driving permits delineation of past-month DUIC frequency. This metric has potential as a component of public health prevention tools.

Marijuana trajectories and associations with driving risk behaviors in Canadian youth

Objective: Research on risky driving practices involving marijuana use among youth and young adults often relies on cross-sectional data, which fail to account for longitudinal changes in substance use patterns. A better understanding of the longitudinal patterns of marijuana use and its effect on risky driving practices during young adulthood is needed in order to better inform prevention efforts. The current study examined whether different longitudinal patterns of marijuana use across the transition from adolescence to young adulthood are associated with impaired driving risks in young adulthood. Methods: Data were from the longitudinal Victoria Healthy Youth Survey, which interviewed youth biennially on 6 occasions across 10 years (2003 to 2013). Results: Youth who reported consistently high levels of marijuana use from adolescence to young adulthood (chronic users) and youth who reported increasing levels of use across this period (increasers) were more likely to engage in risky impaired driving behaviors compared to the other 3 user groups (occasional users, decreasers, and abstainers). Frequency of marijuana use was also predictive of impaired driving risks in young adulthood after controlling for individual characteristics (age, sex, socioeconomic status, age of onset of marijuana use), frequency of other substance use (heavy episodic drinking and illicit drug use), and simultaneous use of marijuana and other substances (alcohol and illicit drugs). By young adulthood, youth who use marijuana more than once a week are more likely to simultaneously use alcohol and engage in heavy episodic drinking. They are also more likely take driving risks. Conclusions: Harm reduction strategies and legislative approaches targeting impaired driving risks associated with marijuana use should include approaches to target these high-risk groups and to reduce simultaneous use of alcohol.

A Socioecological Perspective Regarding Risk Factors for Driving Under the Influence of Marijuana Among Young Adults

Young adults are at high risk for using marijuana, driving under the influence (DUI) of marijuana, and fatalities or serious injuries from motor vehicle crashes related to DUI of marijuana. Within the context of increased legalization of marijuana use and shifting social norms, these public health concerns are particularly prominent. Drawing from a socioecological perspective, this commentary summarizes the literature indicating the importance of multilevel influences on DUI of marijuana among young adults. Indeed, prior research has indicated that risk for DUI of marijuana is associated with policy-level factors such as state and local policies related to marijuana, community-level factors including marijuana access (eg, legalized retail, black market), interpersonal influences including social norms, and intrapersonal factors such as risk perceptions of marijuana use and DUI. This literature should inform future research and practice aiming to develop, test, and implement multilevel interventions and develop messaging strategies aimed at curtailing DUI of marijuana.