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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. [ABSTRACT FROM AUTHOR]

Considering the widespread use of cannabis and opioids, examining the use of cannabis, opioids and their combination with serious psychological distress (SPD) is important. A total of N = 12,358 adults participating in the Monitor surveillance study between 2014 and 2019 were included. Cannabis and opioid use reflected any use of the substances in the past 12 months. SPD was defined as having a score of 13 or more on the Kessler‐6 questionnaire, a 6‐item scale that includes feeling nervous, hopeless, restless or fidgety, sad or depressed. Odds ratios (ORs) were estimated from logistic regression models accounting for complex survey design and sociodemographic factors. Overall, 12.8% of the sample reported cannabis use only, 18% reported opioid use only, and 4.9% reported both cannabis and opioid use. Use of both cannabis and opioids was significantly associated with SPD in both women (OR = 4.24; 95% CI, 2.34 to 7.69), and in men (OR = 2.99; 95% CI, 1.56 to 5.73) compared to use of neither. The joint association of cannabis and opioids with SPD was additive. Addressing those who use both cannabis and opioids may help reduce the burden of SPD among adults in Ontario. [ABSTRACT FROM AUTHOR]

This report assesses sociodemographic correlates of cannabis routes of administration (ROAs) among adolescents in 2017, one year prior to legalization of cannabis in Canada. We analyze a subsample of 809 students (Grades 9–12) from the Ontario Student Drug Use and Health Survey (OSDUHS) who used cannabis in the previous year. Pipes/bongs/waterpipes (81.8%) are the most prevalent ROA, followed by joints (73.8%) and edibles (42%). Approximately 70% of students report 2+ ROAs. Alcohol use in the previous year is associated with 2.28 (1.3–5.58 OR; 95% CI) times the odds of food/drink ROA and 2.91 (1.10–3.89; 95% CI) times the odds of joint ROA. Tobacco use is associated with 1.60 (1.07–2.41 OR; 95% CI) times the odds of blunt ROA, 2.07 (1.10–3.89; 95% CI) times the odds of pipe/bong/waterpipe ROA, and 1.75 (1.03–2.95 OR; 95% CI) times the odds of e-cigarette/vape pen/vaporizer ROA. Students who used alcohol have a rate 1.59 (1.08–2.36 IRR; 95% CI) times greater for total ROA count, and students who used tobacco have a rate 1.24 (1.09–1.40 IRR; 95% CI) times greater. Given young people's vulnerability to adverse outcomes associated with cannabis use, it is important to track ROA trends to inform harm reduction and educational programing and to evaluate impacts of policy changes. [ABSTRACT FROM AUTHOR]

Aim: We conducted a responsibility analysis to determine whether drivers injured in motor vehicle collisions who test positive for Δ‐9‐tetrahydrocannabinol (THC) or other drugs are more likely to have contributed to the crash than those who test negative. Design Prospective case–control study. Setting: Trauma centres in British Columbia, Canada. Participants: Injured drivers who required blood tests for clinical purposes following a motor vehicle collision. Measurements Excess whole blood remaining after clinical use was obtained and broad‐spectrum toxicology testing performed. The analysis quantified alcohol and THC and gave semiquantitative levels of other impairing drugs and medications. Police crash reports were analysed to determine which drivers contributed to the crash (responsible) and which were 'innocently involved' (non‐responsible). We used unconditional logistic regression to determine the likelihood (odds ratio: OR) of crash responsibility in drivers with 0 < THC < 2 ng/ml, 2 ng/ml ≤ THC < 5 ng/ml and THC ≥ 5 ng/ml (all versus THC = 0 ng/ml). Risk estimates were adjusted for age, sex and presence of other impairing substances. Findings We obtained toxicology results on 3005 injured drivers and police reports on 2318. Alcohol was detected in 14.4% of drivers, THC in 8.3%, other drugs in 8.9% and sedating medications in 19.8%. There was no increased risk of crash responsibility in drivers with THC < 2 ng/ml or 2 ≤ THC < 5 ng/ml. In drivers with THC ≥ 5 ng/ml, the adjusted OR was 1.74 [95% confidence interval (CI) = 0.59–6.36; P = 0.35]. There was significantly increased risk of crash responsibility in drivers with blood alcohol concentration (BAC) ≥ 0.08% (OR = 6.00;95% CI = 3.87–9.75; P < 0.01), other recreational drugs detected (OR = 1.82;95% CI = 1.21–2.80; P < 0.01) or sedating medications detected (OR = 1.45; 95%CI = 1.11–1.91; P < 0.01). Conclusions: In this sample of non‐fatally injured motor vehicle drivers in British Columbia, Canada, there was no evidence of increased crash risk in drivers with Δ‐9‐tetrahydrocannabinol < 5 ng/ml and a statistically non‐significant increased risk of crash responsibility (odds ratio = 1.74) in drivers with Δ‐9‐tetrahydrocannabinol ≥ 5 ng/ml. [ABSTRACT FROM AUTHOR]

As provincial and territorial governments across Canada adjust to the federal legalization of cannabis for non-medical use, strategies to deter driving under the influence of cannabis (DUIC) are increasingly attracting attention. Development and evaluation of legal and other measures designed to deter DUIC would benefit from improved understanding of knowledge and beliefs that underpin individuals' engagement in and avoidance of DUIC. In 2017, we conducted 20 interviews with clients of a remedial program for officially processed (i.e., convicted or suspended) impaired drivers. Eligible study participants reported having driven a motor vehicle within an hour of using cannabis in the past year. Using a thematic analytic approach, we observed vague awareness of the content of drug-impaired–driving laws; perceived low likelihood of getting caught by police for DUIC, with some beliefs that enforcement would increase after legalization; and a range of opinions on four key deterrent strategies (i.e., roadside spot-check programs, legal limits for tetrahydrocannabinol, zero tolerance for novice drivers, and remedial programs). Many participants raised concerns about the accuracy of roadside testing procedures and fairness to drivers. Our findings provide new support for elements of legislation and programming that might effectively deter DUIC. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the association of ethnoracial background and immigrant status to cannabis use among students in Ontario, Canada. Data were derived from the Ontario Student Drug Use and Health Survey, a school-based, province-wide survey of students in Grades 7–12. The survey utilized a stratified two-stage cluster design. Analyses were based on a pooled subsample of 12,527 students in Grades 9–12 during the 2011 and 2013 survey cycles and included adjustments for the complex sample design. Results indicate that youth who were of South Asian or East/Southeast Asian background were at lower odds of cannabis use than those who were White, Black, or mixed-race backgrounds. Youth who were of mixed-race background (i.e., White and another group) were at higher odds of cannabis use than youth who were of White background. The association between ethnoracial background and cannabis use also varied for some foreign-born and native-born youth. These findings suggest that ethnoracial background should be an important consideration in investigations of cannabis use among foreign- relative to native-born youth. [ABSTRACT FROM PUBLISHER]

Background: There are knowledge gaps regarding the effectiveness of different approaches designed to prevent and deter driving under the influence of cannabis (DUIC). Policymakers are increasingly interested in evidence-based responses to DUIC as numerous jurisdictions worldwide have legally regulated cannabis or are debating such regulation. We contribute a comprehensive review of international literature on countermeasures that address DUIC, and identify where and how such measures have been evaluated.Methods: The following databases were systematically searched from 1995 to present: Medline, Embase, PsycINFO, CINAHL, Sociological Abstracts, and Criminal Justice Abstracts. Hand searching of relevant documents, internet searches for grey literature, and review of ongoing email alerts were conducted to capture any emerging literature and relevant trends.Results: Numerous international jurisdictions have introduced a variety of measures designed to deter DUIC. Much interest has been generated regarding non-zero per se laws that set fixed legal limits for tetrahydrocannabinol and/or its metabolites detected in drivers. Other approaches include behavioural impairment laws, zero-tolerance per se laws, roadside drug testing, graduated licensing system restrictions, and remedial programs. However, very few evaluations have appeared in the literature.Conclusions: Although some promising results have been reported (e.g., roadside testing), it is premature to draw firm conclusions regarding the broader impacts of general deterrent approaches to DUIC. This review points to the need for a long-term commitment to rigorously evaluate, using multiple methods, the impact of general and specific deterrent DUIC countermeasures. [ABSTRACT FROM AUTHOR]

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Background: Adult attention deficit hyperactivity disorder (ADHD) shows a robust association with alcohol and cannabis misuse, and these relationships are expressed differently in males and females. Manifestation of specific ADHD symptom profiles, even in the absence of the full disorder, may also be related to problems with alcohol and cannabis, although these relationships have not been investigated in epidemiological studies. To address this question, we studied the sex-specific associations of ADHD symptomatology with problematic alcohol and cannabis use in a representative sample of adults aged 18 years and older residing in Ontario, Canada. Methods: Data were obtained from the Centre for Addiction and Mental Health Monitor, an ongoing cross-sectional telephone survey, between January 2011 and December 2013. Respondents (n = 5080) reported on current ADHD symptomatology, measured using the Adult ADHD Self-Report Version 1.1 Screener (ASRS-V1.1) and four additional items, and alcohol and cannabis use, which were measured using the Alcohol Use Disorders Identification Test (AUDIT) and the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), respectively. Logistic regression analyses were conducted in men and women to test the association of each ADHD symptom cluster (hyperactivity, inattentiveness, impulsivity) with problematic alcohol and cannabis use. Results: After controlling for age, education, and comorbid internalizing and externalizing psychopathology, hyperactive symptoms were associated with problematic alcohol use in both men and women and with problematic cannabis use in men. Impulsive symptoms were independently associated with problematic cannabis use in men. By contrast, inattentive symptomatology predicted problems with alcohol and cannabis only in women. In all models, age was negatively associated with substance misuse and externalizing behavior was positively correlated and the strongest predictor of hazardous alcohol and cannabis use. Conclusions: ADHD symptom expression in adulthood is related to concurrent hazardous use of alcohol and cannabis. Distinctive ADHD symptom profiles may confer increased risk for substance misuse in a sex-specific manner. [ABSTRACT FROM AUTHOR]

Abstract: Aim: This study examined whether the predictors of self-reported aggressive driving perpetration and victimization vary across age groups. Method: Based on data from a general-population telephone survey conducted from July 2002 through June 2005, three groups of drivers were examined: 18–34year-olds (N =1522), 35–54year-olds (N =2726), and 55years of age or older (N =1883). For each age group sample, logistic regression analyses examined self-reported aggressive driving perpetration and victimization in the last 12months by measures of driving exposure, heavy drinking, cannabis use, and drinking-driving, while controlling for demographic factors. Results: The prevalence of aggressive driving perpetration within the past year was highest for the youngest age group (51%), followed by the middle-aged group (37%), and then the oldest age group (18%). The same pattern of results was found for prevalence of aggressive driving victimization (54%, 47%, and 31%, respectively). Controlling for demographic factors, the predictors of perpetration were generally consistent across the age groups. The logistic regression model for the youngest drivers revealed that those who reported stressful driving, heavy drinking, and cannabis use had significantly increased odds of reporting perpetration of aggressive driving. For middle-aged and older drivers, stressful driving, driving on busy roads, cannabis use, and driving after drinking were associated with perpetration. In addition, increased mileage contributed to perpetration in the oldest group. The findings for victimization by aggressive driving were similar. The logistic regression model for the youngest age group identified stressful driving, cannabis use, and higher annual mileage as being associated with victimization. For the oldest age group, these same variables were significant predictors of victimization, in addition to driving on busy roads. The logistic regression for the middle-aged group identified the same predictors as that of the oldest age group; however, interestingly driving after drinking was found to predict lower victimization among middle-aged drivers. Conclusions: Although the prevalence of aggressive driving perpetration and victimization declined with age, the factors that contributed to aggressive driving remained generally stable across the lifespan. The results suggest that efforts to reduce aggressive driving among young drivers may prove to be effective for drivers from all age groups. [Copyright &y& Elsevier]

Abstract: Introduction: The purpose of the current study was to examine differences in factors associated with self-reported collision involvement of three age groups of drivers based on a large representative sample of Ontario adults. Method: This study was based on data from the CAMH Monitor, an ongoing cross-sectional telephone survey of Ontario adults 18years and older from 2002 to 2005. Three age groups were examined: 18-34 (n=1,294), 35-54 (n=2,428), and 55+ (n=1,576). For each age group sample, a logistic regression analysis was conducted of self-reported collision involvement in the last 12months by risk factor measures of driving exposure (kilometers driven in a typical week, driving is stressful, and driving on busy roads), consuming five or more drinks of alcohol on one occasion (past 12months), cannabis use (lifetime, and past 12months), and driving after drinking among drinkers (past 12months), controlling for demographics (gender, region, income, and marital status). Results: The study identified differences in factors associated with self-reported collision involvement of the three age groups of adult drivers. The logistic regression model for the youngest group revealed that drivers who reported that driving was stressful at least some of the time, drank five or more drinks on an occasion, and drove after drinking had an increased risk of collision involvement. For the middle age group, those who reported using cannabis in the last 12months had significantly increased odds of reporting collision involvement. None of the risk factor measures showed significant associations with collision risk for older drivers (aged 55+). Impact: The results suggest potential areas for intervention and new directions for future research. [ABSTRACT FROM AUTHOR]

Background: Cannabis use has been linked to anxiety and mood disorders (AMD) in clinical cases, but little research on this relationship has been reported at the epidemiological level. Objectives: We examined the relationship between self-reported frequency of cannabis use and risk for AMD in the general Ontario adult population. Methods: Data were based on the CAMH Monitor survey of Ontario adults from 2001 to 2006 ( n = 14,531). AMD was assessed with the 12-item version of the General Health Questionnaire (GHQ12). Frequency of cannabis use within the past year was grouped into five categories: No use (abstainer), less than once a month but at least once a year, less than once a week but at least once a month, less than daily but at least once a week, almost every day to more than once a day. Logistic regression analysis of AMD and cannabis use was implemented while controlling for demographics and alcohol problems. Results: AMD was most common among heavy cannabis users (used almost every day or more) (18.1%) and lowest for abstainers (8.7%). Compared to abstainers, the risk of AMD was significantly greater for infrequent cannabis users ( OR = 1.43) and heavy cannabis users ( OR = 2.04) but not for those in between. Conclusion: These data provide epidemiological evidence for a link between both light and heavy cannabis use and AMD. Scientific Significance: Recognizing the comorbidity of heavy cannabis use and AMD should facilitate improved treatment efforts. Our results also suggest the possibility that, for some individuals, AMD may occur at relatively low levels of cannabis use. [ABSTRACT FROM AUTHOR]

Abstract: Problem: This study examines the relationships between collision involvement and several measures of cannabis use, including driving after using cannabis, among drivers, based on a population survey of Ontario adults in 2002 and 2003. Method: Logistic regression analyses examined self-reported collision involvement in the last 12 months by lifetime use of cannabis, past year use of cannabis, and past year driving after using cannabis, while controlling for demographic characteristics. Results: We found that the odds of reporting collision involvement was significantly higher among cannabis users, and among those who reported driving after cannabis use. Some evidence for a dose-response relationship was seen as well. Discussion: Cannabis users and people who report driving after cannabis use are also more likely to report being involved in a collision in the past year. These observations suggest that collision prevention efforts could be aimed at these groups. Additional work to determine the causal pathways involved in the relationships observed here is needed. Impact on Industry: None. [Copyright &y& Elsevier]

Prior research has shown that those with alcohol problems have significantly elevated rates of traffic events (i.e. traffic violations and collisions) than licensed drivers from the general population and that treatment is associated with reductions in alcohol-related collisions. However, very little research exists on traffic events and the impact of treatment for cannabis or cocaine clients.The objectives of this research are: (1) to determine whether clients in treatment for a primary problem of alcohol, cannabis or cocaine have significantly elevated rates of traffic events than a matched control group of licensed drivers; and (2) to assess whether a significant reduction in traffic events occurs after treatment for each client group compared to a control group.Driver records of patients admitted to substance abuse treatment in 1994 for a primary problem of alcohol (n=117), cannabis (n=80) or cocaine (n=169) were accessed from the Ministry of Transportation for Ontario, Canada. A comparison group of 504 licensed drivers frequency matched by age, sex and place of residence, was also randomly selected. Data was collapsed into two 6-year time periods: 1988–1993 (i.e. before treatment) and 1995–2000 (i.e. after treatment). Six repeated measures analysis of variance tests were conducted where traffic violations and collisions of three treatment groups (i.e. alcohol, cannabis or cocaine) and a control group were compared before and after treatment.All three treatment groups had significantly more traffic violations than the control group and no significant interactions between time period and group membership were found. For collisions, there was a significant interaction between the alcohol and control groups and between the cocaine and control groups. The average number of collisions for the alcohol and cocaine groups decreased after completing treatment, whereas the number for the control group was stable over the same time periods. Neither the interaction term nor the between group effect was significant in the comparison of the cannabis and control groups. When rates of collisions were calculated based on the period that each driver had a valid license, the interaction term was still significant for the comparison of the alcohol and control groups but not for the cocaine and control groups.The results contribute to existing literature by demonstrating that cocaine and cannabis clients have a higher risk of traffic violations than matched controls and that reductions in collision risk was found after treatment for the alcohol and cocaine groups. More research is needed to better understand the reasons for the higher risk of traffic events and to determine reasons for declines. [Copyright &y& Elsevier]

The authors discuss the need for newer data regarding the use of cannabis by youth. They mention the increased levels of tetrahydrocannabinol and its impact, the greater risk factors for mental illness, and the increased use of marijuana with its legalization as contributing to this need.

LITTLE IS KNOWN ABOUT THE RISK OF INJURY among adolescents who drive after the use of alcohol or cannabis or ride in cars driven by drunk drivers. We examined data from self-administered interviews with 1846 students in grades 7 to 13 who participated in the 2001 Ontario Student Drug Use Survey about their experiences related to alcohol, cannabis and driving during the 12 months preceding the survey. In all, 31.9% of the students reported being a passenger in a car driven by a drunk driver; of the students in grades 10 to 13 who had a driver's licence, 15.1% reported driving within an hour after consuming 2 or more drinks, and 19.7% reported driving within an hour after using cannabis. Our study shows that a sizeable proportion of adolescents are exposed to alcohol- and drug-related driving risks. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the associations of family, school, peer, and attitudinal factors with cannabis use among three immigrant generations of youth. The sample consisted of 3,134 students from the 2009 Ontario Student Drug Use and Health Survey, a province wide survey of 7th- to 12th-grade students. Results indicate that the odds of using cannabis were lower among first-generation immigrant youth than among second as well as third and later generations. The immigrant generations were more similar than different in the significance of family, school, peers, and attitudinal factors on cannabis use. Parental education, however, was found to differ in its effect on cannabis use across generations. Findings suggest that factors that influence cannabis use may be similar across immigrant generations and that further research is needed on the effects of parental education and the mechanisms through which protection and risk to immigrant generations occur. [ABSTRACT FROM AUTHOR]

Background: The effect of cannabis legalization in Canada (in October 2018) on the prevalence of injured drivers testing positive for tetrahydrocannabinol (THC) is unclear.Methods: We studied drivers treated after a motor vehicle collision in four British Columbia trauma centers, with data from January 2013 through March 2020. We included moderately injured drivers (those whose condition warranted blood tests as part of clinical assessment) for whom excess blood remained after clinical testing was complete. Blood was analyzed at the provincial toxicology center. The primary outcomes were a THC level greater than 0, a THC level of at least 2 ng per milliliter (Canadian legal limit), and a THC level of at least 5 ng per milliliter. The secondary outcomes were a THC level of at least 2.5 ng per milliliter plus a blood alcohol level of at least 0.05%; a blood alcohol level greater than 0; and a blood alcohol level of at least 0.08%. We calculated the prevalence of all outcomes before and after legalization. We obtained adjusted prevalence ratios using log-binomial regression to model the association between substance prevalence and legalization after adjustment for relevant covariates.Results: During the study period, 4339 drivers (3550 before legalization and 789 after legalization) met the inclusion criteria. Before legalization, a THC level greater than 0 was detected in 9.2% of drivers, a THC level of at least 2 ng per milliliter in 3.8%, and a THC level of at least 5 ng per milliliter in 1.1%. After legalization, the values were 17.9%, 8.6%, and 3.5%, respectively. After legalization, there was an increased prevalence of drivers with a THC level greater than 0 (adjusted prevalence ratio, 1.33; 95% confidence interval [CI], 1.05 to 1.68), a THC level of at least 2 ng per milliliter (adjusted prevalence ratio, 2.29; 95% CI, 1.52 to 3.45), and a THC level of at least 5 ng per milliliter (adjusted prevalence ratio, 2.05; 95% CI, 1.00 to 4.18). The largest increases in a THC level of at least 2 ng per milliliter were among drivers 50 years of age or older (adjusted prevalence ratio, 5.18; 95% CI, 2.49 to 10.78) and among male drivers (adjusted prevalence ratio, 2.44; 95% CI, 1.60 to 3.74). There were no significant changes in the prevalence of drivers testing positive for alcohol.Conclusions: After cannabis legalization, the prevalence of moderately injured drivers with a THC level of at least 2 ng per milliliter in participating British Columbia trauma centers more than doubled. The increase was largest among older drivers and male drivers. (Funded by the Canadian Institutes of Health Research.). [ABSTRACT FROM AUTHOR]

The purpose of this paper is to review the results and limitations of studies of injury risks associated with cannabis and cocaine use. Three types of fatal and non-fatal injuries are considered: injuries due to collisions, intentional injuries and injuries in general. Four types of studies were reviewed: (I) laboratory studies, (II) descriptive and analytic epidemiological studies on the prevalence of cannabis or cocaine use through drug testing of those injured, (III) studies of non-clinical samples, and (IV) studies of clinical samples of drug users. The research that utilized drug tests showed similar proportions testing positive for cannabis in fatal and non-fatal injury groups, and for collisions, violence and injuries in general. By contrast, large differences in the average proportions testing positive for cocaine were found among these same injury groups. For example, 28.7% of people with intentional injuries (primarily homicides) tested positive for cocaine, while 4.5% of injured drivers tested positive. Studies of non-clinical samples have shown that both cannabis and cocaine use are related to intentional injuries and injuries in general. Results indicate higher risk for all types of injuries among cannabis and cocaine clients in treatment. Strengths and limitations of the different types of studies are discussed. More rigorous studies are needed which should focus on ruling out alternative explanations for relationships between drug use and injuries. [Copyright &y& Elsevier]

Background: Rates of cannabis use differ around the world; in Ontario, the rate of use has been stable since about 2005. Understanding which population groups are at greater risk for problematic cannabis use can help reduce long-term health effects and service expenses. The aim of this study was to explore differences in cannabis use among Canadian adults of different ethnic origins living in Ontario.Methods: Data are based on telephone interviews with 11,560 respondents and are derived from multiple cycles (2005-2011) of the Centre for Addiction and Mental Health's (CAMH) Monitor survey, an ongoing cross-sectional survey of adults in Ontario, Canada, aged 18 years and older. Data were analyzed using bivariate cross-tabulations and logistic regression. Problematic cannabis use was determined with a score of 8+ on the ASSIST-CIS to identify moderate/high problematic users.Results: Lifetime, past year and problematic cannabis use (in the past 3 months) occurs among all ethnic groups: Canadian, East Asian, South East Asian, South Asian, Caribbean, African, East European, South European, North European, and Central West European. When compared to the Canadian group the odds of past year cannabis use was significantly lower for East Asians and South Asians, but higher for the Caribbean group. Significantly higher odds of problematic cannabis use were found for Caribbeans and Northern Europeans compared to Canadians.Conclusions: These results of this study provide an important basis for considering the possible impact of the impending legalization of cannabis in Canada among different ethnic groups. [ABSTRACT FROM AUTHOR]

Introduction: In 2012, 10% of Canadians used cannabis and just under half of those who use cannabis were estimated to have driven under the influence of cannabis. Substantial evidence has accumulated to indicate that driving after cannabis use increases collision risk significantly; however, little is known about the extent and costs associated with cannabis-related traffic collisions. This study quantifies the costs of cannabis-related traffic collisions in the Canadian provinces.Methods: Province and age specific cannabis-attributable fractions (CAFs) were calculated for traffic collisions of varying severity. The CAFs were applied to traffic collision data in order to estimate the total number of persons involved in cannabis-attributable fatal, injury and property damage only collisions. Social cost values, based on willingness-to-pay and direct costs, were applied to estimate the costs associated with cannabis-related traffic collisions. The 95% confidence intervals were calculated using Monte Carlo methodology.Results: Cannabis-attributable traffic collisions were estimated to have caused 75 deaths (95% CI: 0-213), 4407 injuries (95% CI: 20-11,549) and 7794 people (95% CI: 3107-13,086) were involved in property damage only collisions in Canada in 2012, totalling $1,094,972,062 (95% CI: 37,069,392-2,934,108,175) with costs being highest among younger people.Discussion: The cannabis-attributable driving harms and costs are substantial. The harm and cost of cannabis-related collisions is an important factor to consider as Canada looks to legalize and regulate the sale of cannabis. This analysis provides evidence to help inform Canadian policy to reduce the human and economic costs of drug-impaired driving. [ABSTRACT FROM AUTHOR]

Driving under the influence of cannabis (DUIC) is detrimental to road safety. Risk perception is a strong determinant of DUIC behaviour, yet little is known about the factors influencing DUIC risk perception in the general population. The objective of this study was to identify factors associated with risk perceptions of motor vehicle collision and legal consequences due to DUIC and examine whether these perceptions were associated with DUIC behaviour. Data were derived from the 2017 CAMH Monitor, a cross-sectional telephone survey of adults aged 18+ years in Ontario, Canada (n = 1813). Multivariable logistic regression analyses were performed. Approximately 90% of adults overall agreed that DUIC increases motor vehicle collision risk compared to 55% of those reporting past-year DUIC. Being male, less educated, and using cannabis at least monthly were associated with disagreeing that DUIC increases motor vehicle collision risk. Being male, young, and using cannabis at least monthly were associated with agreeing that DUIC is safer than driving under the influence of alcohol (DUIA). Being male and using cannabis less than monthly were associated with agreeing that the chances of getting caught for DUIC are higher than DUIA. Safety but not legal risk perceptions were associated with DUIC behaviour among cannabis-using drivers. Cannabis legalization provides a timely opportunity for DUIC prevention strategies. This study suggests that policymakers should target male cannabis users and highlight the safety risks of DUIC. Further research is needed to assess the effectiveness of prevention measures and the impact of cannabis legalization on DUIC perceptions and behaviour. [ABSTRACT FROM AUTHOR]