Perceptions of cannabis use risk to mental health among youth in Canada, England and the United States from 2017 to 2021.

BACKGROUND: There is little research examining perceptions of cannabis use risk to mental health in countries with differing cannabis regulations. This study therefore examines such perceptions among youth between 2017 and 2021 in Canada (non-medical cannabis legalized in October 2018), England (highly-restricted medical cannabis legalized November 2018), and the US (non-medical cannabis legal in some states). METHODS: Seven repeat cross-sectional online surveys were conducted between July 2017 to August 2021 among youth aged 16-19 in Canada (N=29,420), England (N=28,155), and the US (N=32,974). Logistic regression models, stratified by country, were used to examine perceptions of cannabis use risk to mental health over time, adjusting for age group, sex, race/ethnicity, cannabis use and, for the US only, state-level cannabis legalization. RESULTS: Perceptions that cannabis use posed "no risk" to mental health decreased between July 2017 and August 2021 in Canada (6.1-4.4%; AOR=0.64, 95% CI=0.52-0.78) and the US (14.0-11.3%; AOR=0.74, 0.65-0.84) but not England (3.7-4.5%; AOR=1.21, 0.97-1.52). No significant changes were observed from immediately before (August 2018) to after (August 2019) legalization of non-medical cannabis in Canada (AOR=0.99, 0.83-1.20) or highly-restricted medical cannabis in England (AOR=0.90, 0.70-1.17). In the US, perceptions of "no risk" were more likely in states where cannabis use was illegal (15.0%) compared with legal non-medical (12.2%) (AOR=0.68, 0.63-0.74). CONCLUSION: There were modest decreases in perceptions that cannabis use poses no risk to mental health in Canada and the US between 2017 and 2021 but no clear association with cannabis legalization status.

Trends and Socio-Demographic Differences of Cannabis Vaping in the USA and Canada.

Given the rise in cannabis vaping, it is important to highlight the heterogeneity in vaping different cannabis product because of the potential differences in their health risks. This study aims to estimate the trends and socio-demographic correlates of the use of various cannabis vaping products across jurisdiction with different legal status. Data from the 2018 (n = 27,169) and 2019 (n = 47,747) waves of the International Cannabis Policy Study (ICPS) were used. Respondents aged 16-65 completed web-based surveys. In 2019, proportions of past year vaping of cannabis oil, dried flower and concentrates in the overall sample were highest in U.S. jurisdictions where cannabis was legalized for non-medical use (17.4%, 6.0%, 4.9%), followed by U.S. jurisdiction where non-medical cannabis use is illegal (13.7%, 5.8%, 2.9%), and lowest in Canada (8.1%, 4.4%, 2.1%). Vaping dried flower decreased from 2019 to 2018 in U.S. legal jurisdictions and Canada, while vaping cannabis oil and concentrates increased in all jurisdictions (p < 0.001). The odds of vaping all forms of products were higher among younger respondents (16-55 years), males, respondents with some college education, and persons with low-risk perceptions on daily cannabis vaping. In both ICPS surveys (2018 and 2019), cannabis oil was the most frequently vaped products, followed by dried flower, and concentrates. Detailed measures of product forms for cannabis vaping should be considered in future surveys.

An analysis of cannabis home cultivation and associated risks in Canada, before and after legalization.

Background: In 2018, Canada legalized the use and sale of non-medical cannabis, with most provinces also permitting home cultivation. To advance the knowledge of home cultivation patterns in Canada within the context of legalization, this study examines (1) the demographics and use patterns of cannabis home growers before and after legalization and (2) the relationship between home cultivation and cannabis-related risks, including workplace use and driving after cannabis use(DACU). Data and methods: The study is based on seven waves of the National Cannabis Survey, dating from 2018 to 2019. Descriptive statistics were used to analyze home cultivation across several individual and sociodemographic characteristics pre- and post-legalization. Logistic regression was used to examine whether home cultivation is correlated to selected cannabis-related risks. Results: The rate and demographics of home cultivation remained relatively unchanged post-legalization. Those most likely to cultivate cannabis post-legalization were male; 35 years and older; not single; married, common law, divorced, separated or widowed; lived in the Atlantic provinces; consumed cannabis medically or medically and non-medically on a daily or almost daily basis; had more than a high school diploma; and reported "smoking" as their primary consumption method. Home cultivation was correlated to workplace use but not to DACU. Interpretation: The research provides early insights into home cultivation within a legalized framework. It also shows a relationship between home cultivation and certain cannabis-related risks (e.g., workplace use), suggesting a need for future research to determine whether tailored education and policy interventions are needed to target cannabis home growers.

Trends in the use of cannabis products in Canada and the USA, 2018 - 2020: Findings from the International Cannabis Policy Study.

BACKGROUND AND AIMS: There is little information on consumption patterns across the diverse range of cannabis product types. This paper examines trends in consumption patterns in Canada and the United States (US) between 2018-2020. DESIGN: Repeat cross-sectional surveys were conducted as part of the International Cannabis Policy Study online survey in 2018 (n=27,024), 2019 (n=45,426), and 2020 (n=45,180). SETTING: Respondents were recruited from commercial panels in Canada and US states that had and had not legalized non-medical cannabis (US 'legal' and 'illegal' states, respectively). PARTICIPANTS: Respondents were male and female participants aged 16-65 years. MEASUREMENTS: Data on frequency and consumption amounts were collected for nine types of cannabis products, including dried flower and processed products (e.g., oils and concentrates). Consumers were also asked about mixing cannabis with tobacco. Socio-demographic information was collected. FINDINGS: Dried flower was the most commonly used product, although use in the past 12 months declined between 2018 and 2020 in Canada (81% to 73%), US legal (78% to 72%) and illegal states (81% to 76%; p<0.05 for all). Prevalence of past 12-month use increased for virtually all other product forms, although prevalence of daily use remained stable across years. In 2020, edibles and vape oils were the most commonly used products after flower. Use of non-flower products was highest in US legal states, although similar trends were observed in all jurisdictions. Males were more likely to report using processed products, and vape oils were the most commonly processed product among 16-20-year-olds. Daily use of cannabis flower increased in US legal and illegal states, and average joint size increased across all jurisdictions over time. CONCLUSIONS: Dried flower remains the dominant product in Canada and the US; however, use of processed cannabis products has increased, with the largest increases observed in legal cannabis markets.

Prevalence and use of cannabis products and routes of administration among youth and young adults in Canada and the United States: A systematic review.

BACKGROUND: The current systematic review aimed to summarize the literature on the prevalence of routes of administration and cannabis products used among youth and young adults in Canada and the United States (US). METHODS: Five academic databases were searched in April 2020 and February 2021. Peer-reviewed articles were included if they were a population-based quantitative observational study describing the prevalence of a cannabis product or route of administration among youth and young adults in Canada or the US. Risk of bias was assessed using Hoy and colleagues' risk of bias assessment tool. A narrative review was conducted. RESULTS: Twenty-six studies were identified for the following routes of administration: smoking (n = 16), vaping (n = 21), dabbing (n = 3), oral (n = 13), topical (n = 1); and products: dried flower (n = 2), and concentrates (n = 8). Smoking had the highest prevalence rates among youth and young adults; however, rates of use appeared to reduce over time. Conversely, prevalence of vaping appeared to increase over time. Fewer studies focused on oral or dabbed cannabis but those that did reported prevalence estimates of approximately a third among recent cannabis consumers. DISCUSSION: The heterogeneity of cannabis routes of administration restricted our ability to collate average prevalence estimates. In jurisdictions where non-medical cannabis is legal, policymakers should provide guidance and education to youth on each type of product and routes of administration. OTHER: Funding for this study was provided by a Canadian Institutes of Health Research (PJT-153342). The current review was registered with PROSPERO (CRD42020169275).

Use and Perceptions of Cannabidiol Products in Canada and in the United States.

Objectives: This study aimed to characterize use and perceptions of cannabidiol (CBD) products. Materials and Methods: Participants aged 16-65 years in Canada (n=15,042) and the United States (n=30,288) completed measures on prevalence and patterns of CBD product use and perceptions of CBD oil as part of the 2019 International Cannabis Policy Study online survey. Results: Past 12-month CBD product use was significantly more prevalent among respondents in the United States (26.1%) than in Canada (16.2%). Consumers in the United States and Canada reported using a range of CBD products, including drops (46.3% vs. 47.3%, respectively), topicals (26.0% vs. 16.7%), edibles/foods (23.8% vs. 17.6%), vape oils (18.9% vs. 13.3%), capsules (13.3% vs. 16.7%), and dried flower (10.1% vs. 16.1%). CBD was most commonly reported for management of pain, anxiety, and depression. Over half of CBD consumers in both countries reported that CBD oil was beneficial for health. Conclusions: Use of CBD products is common in both the United States and Canada, primarily to manage self-reported health conditions for which there is little or no evidence of efficacy. Clearer public health messaging regarding the therapeutic effects of CBD is warranted.

Increasing Cannabis Use Is Associated With Poorer Cigarette Smoking Cessation Outcomes: Findings From the ITC Four Country Smoking and Vaping Surveys, 2016-2018.

INTRODUCTION: Concurrent use of tobacco and cannabis may impede successful cigarette smoking cessation. This study examined whether changes in cannabis use frequency were associated with smoking cessation. AIMS AND METHODS: Nationally representative samples of adult cigarette smokers from Canada (n = 1455), the United States (n = 892), England (n = 1416), and Australia (n = 717) were surveyed in 2016 and 2018. In each year, smokers reported how often they used cannabis in the previous 12 months. Reports were compared to determine whether cannabis use increased, remained unchanged, or decreased. Smoking cessation outcomes, measured in 2018, were (1) any attempt to quit in the previous year, (2) currently quit, and (3) currently quit for at least 6 months. Weighted multivariable logistic regression estimated the association between changes in cannabis use and cessation outcomes. RESULTS: Cigarette smokers who increased their frequency of cannabis use were significantly less likely to be currently quit than noncannabis-using smokers (adjusted odds ratio (aOR) = 0.52, 95% CI = 0.31% to 0.86%); they were also less likely to have quit for at least 6 months (aOR = 0.30; 95% CI = 0.15% to 0.62%). CONCLUSIONS: Smokers who increase their frequency of cannabis use have poorer smoking cessation outcomes compared to noncannabis-using smokers. It will be important to monitor the impact of cannabis legalization on patterns of cannabis use, and whether this influences cigarette smoking cessation rates. IMPLICATIONS: Cigarette smokers who start using cannabis may be less likely to quit cigarettes compared with smokers who do not use cannabis at all. If smokers who also use cannabis are more likely to continue smoking, it is important to monitor these trends and understand the impact, if any, on smoking cessation in jurisdictions that have legalized cannabis for nonmedical use.

Prevalence and modes of cannabis use among youth in Canada, England, and the US, 2017 to 2019.

OBJECTIVE: Cannabis markets are evolving in terms of greater diversity and potency of products. The current study examined changes in cannabis use and modes of consumption among 16- to 19-year-olds in three markets with different regulatory frameworks: England, Canada, and the United States (US). METHODS: Repeat cross-sectional online surveys were conducted in 2017, 2018, and 2019, with samples of 16- to 19-year-olds recruited from commercial panels in Canada (n = 11,779), England (n = 11,117), and the US (n = 11,869). Regression models examined changes in the prevalence of any cannabis use and use of seven modes of consumption, across the countries. RESULTS: Cannabis use among youth was more prevalent among respondents in Canada and the US than in England in all years and increased to a greater extent between 2017 and 2019 (p < .001 for all contrasts). Among past 30-day cannabis consumers, the prevalence of vaping oils/liquids and the use of cannabis extracts (oil, wax and shatter) increased in all countries, and was significantly higher in Canada and US. For example, the prevalence of vaping oils/liquids increased from 24.2 % in 2017 to 52.1 % in 2019 among past 30-day cannabis consumers in the US (AOR = 3.46, 95 %CI = 2.57-4.66). CONCLUSION: Prevalence is increasing for the most potent categories of cannabis products, particularly among youth in Canada and the US. Future research should examine the potential risks of these products and whether shifts in modes of cannabis reflect recent permissive changes to cannabis policy.

Modes of delivery in concurrent nicotine and cannabis use ("co-use") among youth: Findings from the International Tobacco Control (ITC) Survey.

BACKGROUND: Cannabis use is more common among nicotine users than non-users. This study characterized concurrent use of nicotine and cannabis ("co-use") among 12,064 youth aged 16-19 years residing in Canada, the United States, and England in 2017. Methods: Data were from the ITC Youth Tobacco & Vaping Survey (Wave 1). Seven modes of cannabis delivery (MOD) were characterized by country of residence and past 30-day use of combusted tobacco and electronic cigarettes. Weighted multivariable regression models were fitted to assess the correlates of co-use and each cannabis MOD. Results: Seventy percent of cannabis users reported nicotine use. Co-users exhibited behavioral and demographic differences compared to exclusive users of either substance. "Smoking cannabis without tobacco" was the most popular form of use (78%). Use of nicotine-containing e-cigarettes was associated with "using an e-cigarette to vape cannabis oil/liquid" (aOR: 4.96, 95%CI: 2.23-11.06). Combustible tobacco use was associated with "smoking cannabis with tobacco in a joint/blunt" (aOR: 2.93, 95%CI: 1.89-4.56). Country-level differences were detected. Conclusions: Nicotine use is substantial among cannabis users, and associations exist between modes of delivery for both drugs. Results underscore the importance of studying cannabis and nicotine use concurrently, and the need to address the use of both substances in developing interventions for youth users.

Prevalence and forms of cannabis use in legal vs. illegal recreational cannabis markets.

BACKGROUND: Recreational or 'non-medical cannabis' has been legalized in several US states, and was legalized federally in Canada in October 2018. There is little comparative data on product use across jurisdictions, particularly with respect to the types of cannabis products used, which differentially impact health. METHODS: Data are from Wave 1 of the International Cannabis Policy Study, collected from Aug 27-Oct 7, 2018. Respondents (n = 27,024) aged 16-65 completed an online survey measuring patterns of cannabis use, quantities and routes of administration. Respondents were recruited from Canada (n = 9976) and US states that had (n = 7362) and had not (n = 9686) legalized non-medical cannabis ('legal' and 'illegal' states, respectively). RESULTS: Prevalence of at least daily, weekly, and monthly cannabis use were significantly higher in US 'legal' states (11.3%, 18.2%, 25.0%, respectively) than US 'illegal' states (7.4%, 11.6%, 16.8%, respectively; p<0.001) and Canada (8.9%, 14.1%, 19.0%, respectively; p ≤ 0.01). Dried herb was the dominant form of cannabis reported by past 12-month users across all jurisdictions (77.7%-80.8%). Although the amount of dried herb used per year did not differ by jurisdiction (range: 210.3-229.4 g), those in US 'legal' states were significantly more likely to use dried herb daily or weekly than were those in 'illegal' states and Canada (p<0.001). Use of cannabis concentrates, vaped oils, edibles, and drinks was more prevalent among US 'legal' states than 'illegal' states and Canada (p ≤ 0.001). Vaping dried herb was more common in both legal and illegal US jurisdictions than in Canada (p<0.05), whereas Canadians were more likely to smoke dried herb with tobacco (p<0.001). CONCLUSION: The prevalence of cannabis use-and use of products such as cannabis concentrates, edibles and drinks-was higher in US states that had legalized cannabis. Additional longitudinal research is required to determine whether these differences reflect causal effects of legalization or pre-existing secular trends.

Mental Health and Medical Cannabis Use among Youth and Young Adults in Canada.

Background: In October 2018, Canada became the second country to legalize non-medical cannabis. However, medical cannabis has been legally available in Canada since 2001 and, in 2015, approximately 800,000 Canadians reported using cannabis for medical purposes. Mental health is a common reason reported for using medical cannabis. Objectives: The current study examined perceived mental health among four groups: (1) Non/ex-users; (2) Recent non-medical users; (3) Recent unauthorized medical users; and (4) Recent authorized medical users. Methods: A total of 867 Canadian cannabis users and nonusers aged 16 to 30 were recruited through an online consumer panel in 2017, one year before non-medical cannabis legalization. Logistic and multinomial regression models were fitted to examine differences among cannabis use status and mental health measures. All estimates represent weighted data. Results: Self-reported emotional and mental health problems were higher among unauthorized (83.9%) and authorized medical cannabis users (83.2%) compared to non-medical users and non/ex-users (44.5% and 39.5%, respectively). Medical users were more likely to report using cannabis to manage or improve mental health problems than non-medical users (p < .001). There were few differences between unauthorized and authorized medical users, and between non/ex-users and non-medical users. Conclusions: The findings highlight a discrepancy between the recommendation that individuals with some mental health problems should avoid cannabis and the widespread practice of using cannabis to manage mental health. Education and reduced stigma around using cannabis after legalization in Canada may help address users coming forwards regarding use of cannabis for mental health problems.

Differences in patterns of cannabis use among youth: Prevalence, perceptions of harm and driving under the influence in the USA where non-medical cannabis markets have been established, proposed and prohibited.

INTRODUCTION AND AIMS: Cannabis use is the most widely used illicit substance in the USA. Currently, over half of US jurisdictions have legalised medical cannabis and nine US jurisdictions (and Washington DC) have legalised non-medical cannabis. Comparisons across jurisdictions can help to evaluate the impact of these policies. The current study examined patterns of cannabis use among youth in three categories: (i) states that have legalised non-medical cannabis with established markets; (ii) jurisdictions that recently legalised non-medical cannabis without established markets; and (iii) all other jurisdictions where non-medical cannabis is prohibited. DESIGN AND METHODS: Data come from an online survey conducted among 4097 US youth aged 16-19 recruited through a commercial panel in July/August 2017. Regression models were fitted to examine differences between regulatory categories for cannabis consumption, perceived access to cannabis, modes of use, perceptions of harm and cannabis-impaired driving. All estimates represent weighted data. RESULTS: States that had legalised non-medical cannabis had higher prevalence, easier access and lower driving rates than non-legal states. There were few differences between states with established non-medical cannabis markets and those that had recently legalised. DISCUSSION AND CONCLUSIONS: Cannabis use among youth was higher in states that have legalised non-medical cannabis, regardless of how long the policy had been implemented or whether markets had been established. This suggests that differences between states with and without legal non-medical cannabis may partly be due to longer-term patterns established prior and highlights the importance of longitudinal evidence to evaluate the impact of cannabis policies.

How and Why Do Smokers Start Using E-Cigarettes? Qualitative Study of Vapers in London, UK.

The aims of the study were to (1) describe how and why smokers start to vape and what products they use; (2) relate findings to the COM-B theory of behaviour change (three conditions are necessary for behaviour change (B): capability (C), opportunity (O), and motivation (M)); and (3) to consider implications for e-cigarette policy research. Semi-structured interviews (n = 30) were conducted in London, UK, with smokers or ex-smokers who were currently using or had used e-cigarettes. E-cigarette initiation (behaviour) was facilitated by: capability (physical capability to use an e-cigarette and psychological capability to understand that using e-cigarettes was less harmful than smoking); opportunity (physical opportunity to access e-cigarettes in shops, at a lower cost than cigarettes, and to vape in "smoke-free" environments, as well as social opportunity to vape with friends and family); and motivation (automatic motivation including curiosity, and reflective motivation, including self-conscious decision-making processes related to perceived health benefits). The application of the COM-B model identified multiple factors that may lead to e-cigarette initiation, including those that could be influenced by policy, such as price relative to cigarettes and use in smoke-free environments. The effects of these policies on initiation should be further investigated along with the possible moderating/mediating effects of social support.