Driving Under the Influence of Cannabis: A Framework for Future Policy

Marijuana is the most widely consumed illicit substance in the United States, and an increasing number of states have legalized it for both medicinal and recreational purposes. As it becomes more readily available, there will be a concurrent rise in the number of users and, consequently, the number of motor vehicle operators driving under the influence. This article examines the cognitive and psychomotor effects of cannabis, as well as current policy concerning driving under the influence of drugs. The authors performed a MEDLINE search on the epidemiology of cannabis use, its cognitive and psychomotor effects, and policies regarding driving under the influence of drugs. Twenty-eight epidemiological studies, 16 acute cognitive and psychomotor studies, 8 chronic cognitive and psychomotor studies, and pertinent state and federal laws and policies were reviewed. These search results revealed that marijuana use is associated with significant cognitive and psychomotor effects. In addition, the legalization of marijuana varies from state to state, as do the laws pertaining to driving under the influence of drugs. Marijuana is a commonly found illicit substance in motor vehicle operators driving under the influence of drugs. Current evidence shows that blood levels of tetrahydrocannabinol do not correlate well with the level of impairment. In addition, although acute infrequent use of cannabis typically leads to cognitive and psychomotor impairment, this is not consistently the case for chronic heavy use. To establish the framework for driving under the influence of cannabis policy, we must review the current published evidence and examine existing policy at state and federal levels.

Prelegalisation patterns and trends of cannabis use among Canadian youth: results from the COMPASS prospective cohort study

OBJECTIVE

Canada federally legalised recreational cannabis use among adults in October 2018. The impact this will have on Canadian youth is cause for concern. The current study examined changes in youth cannabis use over the time prior to legalisation to explore the impact of the beginning federal discourse around legalisation during the 2016/2017 school year.

DESIGN

COMPASS, a prospective cohort study based on annual self-administered questionnaires.

SETTING

Ontario and Alberta during the first 6 years of the COMPASS study (2012/2013 to 2017/2018).

PARTICIPANTS

Canadian grade 9-12 students attending secondary schools participating in COMPASS. In total, 2 30 404 questionnaires were included in the analysis (Y1: 2012/2013, n=24 173; Y2: 2013/2014, n=45 298; Y3: 2014/2015, n=42 355, Y4: 2015/2016, n=40 436; Y5: 2016/2017, n=37 060; Y6: 2017/2018, n=34 897).

PRIMARY AND SECONDARY OUTCOME MEASURES

Lifetime cannabis use, past-year cannabis use, weekly cannabis use, ease of access to cannabis and age at first cannabis use.

RESULTS

Cannabis never-use decreased between Y5 and Y6. Changes in age at first cannabis use mirrored this trend, with male students consistently starting younger. Cannabis access rates increased from Y4, mainly led by female students. Lifetime and past-year use rates were lowest in Y4 then increased in Y5 and Y6 due to a rise in the occasional use more common among female students, who reported use increases first. Non-white students were more likely use cannabis, with black and Aboriginal students the only two groups consistently reporting more weekly than occasional use, though with opposing trajectories. Overall, Aboriginal students had the highest odds of reporting lifetime, past-year and weekly use among the demographic groups examined.

CONCLUSION

After a steady decrease in patterns of cannabis among youth over several years, it appears that there has been a gradual increase in cannabis use among youth following the start of discourse around cannabis legalisation, with some populations of youth being at greater risk.

Cannabis use among a nationally representative cross-sectional sample of smokers and non-smokers in the Netherlands: results from the 2015 ITC Netherlands Gold Magic Survey

OBJECTIVES

Existing evidence shows that co-occurring use of tobacco and cannabis is widespread. Patterns of co-use of tobacco and cannabis may change as more jurisdictions legalise medicinal and/or recreational cannabis sales. This analysis examined predictors of current cannabis use and characterised methods of consumption among smokers and non-smokers in a context where cannabis use is legal.

SETTING

The 2015 International Tobacco Control Netherlands-Gold Magic Survey conducted between July and August 2015.

PARTICIPANTS

Participants (n=1599; 1003 current smokers, 283 former smokers and 390 non-smokers) were asked to report their current (past 30-day) use of cigarettes and cannabis. Cigarette smokers reported whether they primarily used factory made of roll-your-own cigarettes. Those who reported any cannabis use in the last 30 days were asked about forms of cannabis used. X2and logistic regression analyses were used to assess relationships among combustible tobacco and cannabis use.

RESULTS

Past 30-day cannabis use was somewhat higher among current tobacco (or cigarette) smokers (n=57/987=5.8%) than among former or never smokers (n=10/288=3.5% and n=6/316=1.9%, respectively). Joints were the most commonly used form of cannabis use for both current cigarette smokers (96.9%) and non-smokers (76.5%). Among those who smoked cannabis joints, 95% current smokers and 67% of non-smokers reported that they 'always' roll cannabis with tobacco.

CONCLUSIONS

In this Netherlands-based sample, most cannabis was reported to be consumed via smoking joints, most often mixed with tobacco. This behaviour may present unique health concerns for non-cigarette smoking cannabis users, since tobacco use could lead to nicotine dependence. Moreover, many non-cigarette smoking cannabis users appear to be misclassified as to their actual tobacco/nicotine exposure.

[Discussing possible new regulations in german cannabis policy with special regard to the experiences in the Netherlands and Colorado]

In Deutschland wird seit einiger Zeit zunehmend über eine neue Cannabispolitik nachgedacht. Von vielen Seiten wird die Forderung nach einer Liberalisierung oder Freigabe des Cannabis laut. Der vorliegende Artikel fasst die wichtigsten Erfahrungen der Cannabis-Politik aus den Niederlanden und dem US-Bundesstaat Colorado zusammen und versucht, daraus Schlussfolgerungen für eine mögliche Neuregulierung der Cannabispolitik in Deutschland abzuleiten.

Reefer madness or much ado about nothing? Cannabis legalization outcomes among young adults in the United States

In 2012, Colorado became one of the first two U.S. States to legalize cannabis for recreational use for adults 21 and older. Given that cannabis use holds potential physical and mental health risks, particularly among adolescent users, concerns have grown regarding changes in use following this change in policy. Studies examining medical cannabis legalization have found inconsistent changes in cannabis use and prevalence of dependence following medical implementation. However, recreational legalization holds potential unique changes, such as increased availability and social acceptance, as well as decreased price and perceived harm of use. There also may be increased interest in moving to Colorado related to the changes in cannabis laws. Based on past literature, two hypotheses were made for this study. First, college student cannabis use would increase after recreational legalization, however just for those 21 years old and older. Second, there would be a positive relation between the influence of cannabis legislation on out-of-State student's decision to attend a Colorado university and their cannabis use. Data from 5241 undergraduate students was available to test study hypotheses using Pearson's Chi-square, negative binomial regressions, and path analysis. Results indicated that cannabis use increased since recreational legalization for all students, but more so for those over 21 years. No differences in past month use frequency were found between pre- and post-legalization. Influence of cannabis laws on non-resident student's decision to attend a Colorado college predicted lifetime and past 30-day use. Additionally, out-of-State students reported higher past 30-day use than in-State students. These findings may help inform other States considering recreational legalization of potential outcomes, as well as potential interventions.

Review of the public health risks of widespread cannabis use

This article is a review of the public health risks of widespread cannabis use based on a recent review of the literature. The purpose of this article is to help physicians better educate the public about the dangers of widespread cannabis products.

Do medical marijuana laws reduce addictions and deaths related to pain killers?

Recent work finds that medical marijuana laws reduce the daily doses filled for opioid analgesics among Medicare Part-D and Medicaid enrollees, as well as population-wide opioid overdose deaths. We replicate the result for opioid overdose deaths and explore the potential mechanism. The key feature of a medical marijuana law that facilitates a reduction in overdose death rates is a relatively liberal allowance for dispensaries. As states have become more stringent in their regulation of dispensaries, the protective value generally has fallen. These findings suggest that broader access to medical marijuana facilitates substitution of marijuana for powerful and addictive opioids.

Clinical Challenges in the Growing Medical Marijuana Field

Unique clinical challenges arise with the growing number of patients who possess medical marijuana cards. Medical marijuana patients with mental disorders can have worsening symptoms with marijuana use. Often there is sparse continuity of care between the patient and the medical marijuana practitioner. Lack of communication between the patient's treating practitioners and the practitioner who has authorized the medical marijuana can be problematic. This article is a discussion of the new clinical challenges practitioners are likely to encounter with the growing number of medical marijuana patients.

Commentary: Navigating the complexities of marijuana

Science needs to drive our thinking as we navigate a new legislative environment in which many Americans have access to marijuana for therapeutic or recreational use. With the responsibility to fund, conduct, and make use of the research on marijuana, and understand the impacts of new policies, comes the obligation of not thinking in simplistic, black-and-white terms about this substance. The drug's unique harms include neurodevelopmental impacts that may be long lasting or permanent, yet some evidence suggests the drug may benefit people with certain medical conditions (e.g., chronic pain). Marijuana use is also entangled with other substance use and should not be considered in isolation. Finally, policy options are not limited to the extremes of prohibition vs. full commercialization; a spectrum of intermediate options can and should be considered and evaluated as states create new policies around this drug.

Broad Thinking: An Interview With Harold Kalant

In this interview, Harold Kalant, M.D., Ph.D., professor emeritus at the University of Toronto, talks about his career in addiction science; his professional associations with E. M. Jellinek, Griffith Edwards, and other luminaries; the growth of the addiction field; and the issue of cannabis legalization in Canada, among other topics.

Can we make cannabis safer?

Cannabis use and related problems are on the rise globally alongside an increase in the potency of cannabis sold on both black and legal markets. Additionally, there has been a shift towards abandoning prohibition for a less punitive and more permissive legal stance on cannabis, such as decriminalisation and legalisation. It is therefore crucial that we explore new and innovative ways to reduce harm. Research has found cannabis with high concentrations of its main active ingredient, δ-9-tetrahydrocannabinol (THC), to be more harmful (in terms of causing the main risks associated with cannabis use, such as addiction, psychosis, and cognitive impairment) than cannabis with lower concentrations of THC. By contrast, cannabidiol, which is a non-intoxicating and potentially therapeutic component of cannabis, has been found to reduce the negative effects of cannabis use. Here, we briefly review findings from studies investigating various types of cannabis and discuss how future research can help to better understand and reduce the risks of cannabis use.

Community-level policy responses to state marijuana legalization in Washington State

BACKGROUND

Washington State (WA) legalized a recreational marijuana market - including growing, processing and retail sales - through voter initiative 502 in November 2012. Legalized recreational marijuana retail sales began in July 2014. In response to state legalization of recreational marijuana, some cities and counties within the state have passed local ordinances that either further regulated marijuana markets, or banned them completely. The purpose of this study is to describe local-level marijuana regulations on recreational retail sales within the context of a state that had legalized a recreational marijuana market.

METHODS

Marijuana-related ordinances were collected from all 142 cities in the state with more than 3000 residents and from all 39 counties. Policies that were in place as of June 30, 2016 - two years after the state's recreational market opening - to regulate recreational marijuana retail sales within communities were systematically coded.

RESULTS

A total of 125 cities and 30 counties had passed local ordinances to address recreational marijuana retail sales. Multiple communities implemented retail market bans, including some temporary bans (moratoria) while studying whether to pursue other policy options. As of June 30, 2016, 30% of the state population lived in places that had temporarily or permanently banned retail sales. Communities most frequently enacted zoning policies explicitly regulating where marijuana businesses could be established. Other policies included in ordinances placed limits on business hours and distance requirements (buffers) between marijuana businesses and youth-related land use types or other sensitive areas.

CONCLUSIONS

State legalization does not necessarily result in uniform community environments that regulate recreational marijuana markets. Local ordinances vary among communities within Washington following statewide legalization. Further study is needed to describe how such local policies affect variation in public health and social outcomes.

Colorado Medical Students' Attitudes and Beliefs About Marijuana

BACKGROUND

Over the past two decades, state and local governments across the U.S. have been increasingly reforming marijuana laws. Despite growing support for marijuana as a medical treatment, little is known about medical students' perceptions of marijuana use.

OBJECTIVE

To assess Colorado medical students' personal and professional opinions on current and future marijuana use in a healthcare setting.

DESIGN

A voluntary, anonymous, online cross-sectional survey.

PARTICIPANTS

Medical students (n = 624) at the University of Colorado School of Medicine between January and February 2014 were invited to participate.

MAIN MEASURES

Numerical responses were quantified using counts and percentages, and Likert scale responses were collapsed for bivariate analysis. Items were gathered thematically and additively scored for each subscale. Internal consistency reliability statistics were calculated for each subscale to ensure that items were assessing similar constructs. Unadjusted t tests and one-way analysis of variance (ANOVA) were used to calculate mean differences in subscale scores between subgroups.

KEY RESULTS

We received 236 responses (37%). Students indicated support for marijuana legalization (64%), and few believed that physicians should be penalized for recommending marijuana to patients (6%). Nearly all (97%) believed that further marijuana research should be conducted, and believed marijuana could play a role in the treatment of various medical conditions. Seventy-seven percent reported that they believed marijuana use had the potential for psychological harm, and 68% indicated concern for potential physical harm. Only a minority of students would recommend marijuana to a patient under current law (29%), or if it were legally available (45%). Acceptability of marijuana for treatment of approved conditions was not correlated with age or gender, but was positively correlated with living in Colorado prior to medical school (p < 0.001) and with prior marijuana use (p < 0.001).

CONCLUSIONS

Medical students support marijuana legal reform, medicinal uses of marijuana, and increased research, but have concerns regarding risks of marijuana use, and appear hesitant to recommend marijuana to patients.

Pediatric Concerns Due to Expanded Cannabis Use: Unintended Consequences of Legalization

An "unintended consequence" of marijuana legalization is the impact on the pediatric population. From prenatal exposure to unintentional childhood exposures, through concerns of adolescence abuse and marijuana use for medicinal indications in children, marijuana exposure can affect pediatric patients at every stage in childhood. Regardless of the stage or reason of exposure, concerns exist about short-term and long-term consequences in a child's physical and mental health. The use of cannabidiol (CBD) may have some benefit for the treatment of epilepsy, but emphasis needs to be on rigorous clinical trials to evaluate efficacy and safety. As more states allow both medical and recreational marijuana, availability and prevalence of use will likely increase and more surveillance and research is needed to evaluate the consequences on the pediatric population.

Is the Legalization of Marijuana Associated With Its Use by Adolescents?

BACKGROUND

Growing moves in the U.S. toward relaxed laws surrounding adult use of marijuana raise concerns about concurrent increases in adolescent use of marijuana.

OBJECTIVES

This study collected and analyzed primary data on the relationship between marijuana legalization status in U.S. states and adolescents' marijuana use.

METHODS

Recruited through social networking sites and youth-services community agencies, a sample of 1,310 adolescents from 48 U.S. states and the District of Columbia reported their use of marijuana. Youths' use rates were compared with the marijuana legalization status of youths' states of residence.

RESULTS

Study findings failed to show a relationship between adolescents' use of marijuana and state laws regarding marijuana use. Relationships were found for increased marijuana use by older youths, females, and non-Hispanic youths. Youths whose parents completed 2 or more years of college were less likely to report marijuana use than those whose parents completed fewer than 2 years of college.

CONCLUSIONS

Albeit study findings do not support predictions of growing marijuana use by adolescents in states with liberalized adult use laws, further monitoring of adolescents' use with larger and more representative samples is needed.