Understanding youth and young adult cannabis use in Canada post-legalization: a scoping review on a public health issue.

BACKGROUND: Canada legalized recreational cannabis in 2018, and one of the primary objectives of the Cannabis Act was to protect youth by reducing their access to cannabis and providing public education. Canada has the highest prevalence of cannabis use worldwide, particularly among youth and young adults under the age of 25. Cannabis use is linked with many adverse effects for youth and young adults including psychosis, anxiety, depression, respiratory distress, cannabinoid hyperemesis syndrome, and impaired cognitive performance. Despite the high prevalence of cannabis use and the evolution of policies in Canada and globally, significant knowledge and research gaps remain regarding youth and young adult cannabis use. The aim of this scoping review is to map the extent, nature, and range of evidence available on youth and young adult cannabis use in Canada since its legalization, in order to strengthen policies, services, treatments, training, and public education strategies. METHODS: Using a scoping review framework developed by Arksey and O'Malley, along with the PRISMA-ScR guidelines, we conducted a rigorous search in five academic databases: MEDLINE, Embase, APA PsycINFO, CINAHL and Web of Science Core Collection. We included empirical studies that collected data in Canada after the legalization of recreational cannabis (October 2018) and focused on youth or young adults < 30. Two reviewers independently screened articles in two stages and extracted relevant information from articles meeting the inclusion criteria. RESULTS: Of the 47 articles meeting our inclusion criteria, 92% used quantitative methods, 6% were qualitative, and 2% used a mixed-methods approach. Over two-thirds (68%) used secondary data. These studies were categorized into six focus areas: (1) prevalence, patterns, and trends, (2) cannabis-related injuries and emergency department (ED) visits, (3) rates and patterns during the pandemic, (4) perceptions of cannabis use, (5) prevention tools, and (6) cannabis-related offenses. Key findings from the studies reviewed include an increase in cannabis use among 18-24-year-olds post-legalization, with mixed results for youth under 18. ED visits for intentional and unintentional cannabis-related injuries have increased in young children and teens. Perception studies show a mix of concern and normalization of cannabis use. Though limited, prevention studies are promising in raising awareness. A decline in cannabis-related offenses was noted by one study. The review highlights several research gaps, including the need for more qualitative data, disaggregation of demographic data, intervention research, and comprehensive studies on the physical and mental health impacts of cannabis use among youth and young adults. CONCLUSION: Maintaining a public health approach is critical, with a focus on reducing the high prevalence of cannabis use among youth and young adults. This involves implementing prevention strategies to minimize harms, enhancing public education, minimizing commercialization, reducing youth access to cannabis, promoting guidelines for lower-risk cannabis use and harm reduction strategies, and increasing training for healthcare providers.

Clinician perspectives on adolescent cannabis-related beliefs and behaviors following recreational cannabis legalization.

BACKGROUND: As more states legalize cannabis, studies are needed to understand the potential impacts of recreational cannabis legalization (RCL) on adolescents from the perspective of clinicians who care for them. METHODS: This qualitative study characterized clinician perspectives on whether cannabis legalization is associated with changes in adolescents' cannabis use beliefs, behaviors, and consequences. Semi-structured qualitative interviews were conducted with 32 clinicians in a large healthcare organization from 9/6/2022-12/21/2022. Video-recorded interviews were transcribed and analyzed using thematic analysis. RESULTS: The 32 participants (56.3 % female, mean [SD] age, 45.9 [7.6] years; 65.3 % non-Hispanic White) were from Addiction Medicine (n = 13), Psychiatry/Mental Health (n = 7), Pediatrics (n = 5), and the Emergency Department (n = 7). Clinicians described post-RCL increases in adolescent cannabis use, use of non-combustible modes and high-potency products, and younger age of first use. Clinicians reported social, physical, and policy changes, including changes in social norms, appealing advertisements, marketing, and easier access. Many noted fewer perceived harms among adolescents and greater self-medication post-RCL. They described how RCL contributed to increased parental cannabis use and permissiveness around adolescent use. Finally, many described post-RCL increases in cannabis hyperemesis syndrome, and several noted increased cannabis-related psychosis and acute intoxication, and decreased court-mandated treatment. CONCLUSIONS: Clinicians from diverse specialties described post-RCL increases in adolescent cannabis use and cannabis-related consequences, alongside changes in social norms, access, marketing and advertisements, and decreased perceptions of harms. Findings can inform strategies to support adolescents in the context of increased cannabis availability and acceptability post-legalization and support the development of hypotheses for broader-scale quantitative work.

Changing cannabis legislation in Canada and a longitudinal look at "regular" cannabis use in patients with eating disorders.

Regular cannabis use (CU), defined as "weekly or more often", is associated with a number of negative mental health outcomes. In the last decade, Canada legalized first medical and then recreational CU. Despite higher prevalence in mental health populations, little research has documented changes in frequency of CU with progressive legalization of cannabis. This study examined rates of CU in a sample of 843 treatment-seeking patients with eating disorders (ED) in an outpatient setting between 2004 and 2020. Across ED diagnoses, segmented regression indicated a significant break-point in regular CU in 2014, commensurate with the relaxation of medical cannabis laws. Regular CU increased from 4.9 % to 23.7 % from 2014 to 2020; well above the stable 6 % found in the general population. No significant break-point was observed in either alcohol or illicit substance use over the same time period. Significant increases in regular CU were found in patients with anorexia nervosa and binge eating disorder, while regular use remained stable in patients with bulimia nervosa. Comorbid psychiatric diagnoses did not increase odds of regular CU. Findings suggest certain patient groups with mental illness may be at risk of engaging in high frequency use in the context of legislation implying medical benefits of cannabis.

Exploring the effects of cannabis health warnings on protective health intentions among US adults in legal recreational states.

BACKGROUND: As cannabis policy trends toward liberalization, assessing cannabis health warning effects becomes increasingly important. This study investigated underlying mechanisms accounting for the effectiveness of cannabis health warnings on protective health intentions. METHOD: A sample of 1,095 adults (21+) living in legal recreational US states who reported using cannabis in the past 12 months participated in an online experiment. Participants were randomly assigned to view cannabis health warnings that described risks of impaired driving, mental health, and smoke exposure and varied pictures and text (vs. text-only) attributes in warnings. Outcomes were message reactions (cognitive elaboration, fear, and hope), attitudes and beliefs (perceived severity of cannabis harms and perceived susceptibility to cannabis harms, and perceived response and self-efficacy to prevent cannabis harms), and protective health intentions (information-seeking about cannabis health effects and having interpersonal discussions about cannabis harms with family, friends, and medical professionals). RESULTS: MANCOVA results showed no significant differences between text-only vs. pictorial attributes on protective health intentions; thus, warning conditions were controlled and analyzed using structural equation modeling (SEM). SEM results showed that attention to cannabis health warnings (text-only or pictorial) elicited higher cognitive elaboration, fear, and hope-an emotion associated with coping actions that motivate positive expectations of future events. These outcomes, in turn, were associated with greater perceived severity and susceptibility and greater perceived response efficacy, respectively. Hope, perceived severity, and perceived response and self-efficacy were independently associated with greater intentions to seek information about cannabis health effects and to discuss cannabis health harms. CONCLUSION: Attention to warnings impacted emotions, attitudes, and protective health intentions. Fear is commonly associated with health warning effects, and our results suggest that hope is also an important factor. This research contributes to understanding the effects of cannabis health warnings and can inform regulatory agencies that mandate warnings on cannabis products.

Recreational Cannabis Legalization, Retail Sales, and Adolescent Substance Use Through 2021.

This cross-sectional study using survey datasets evaluates recreational cannabis legalization and retail sales policies and adolescent substance use through 2021.

Adolescent Δ8-THC and Marijuana Use in the US.

Importance: Gummies, flavored vaping devices, and other cannabis products containing psychoactive hemp-derived Δ8-tetrahydrocannabinol (THC) are increasingly marketed in the US with claims of being federally legal and comparable to marijuana. National data on prevalence and correlates of Δ8-THC use and comparisons to marijuana use among adolescents in the US are lacking. Objective: To estimate the self-reported prevalence of and sociodemographic and policy factors associated with Δ8-THC and marijuana use among US adolescents in the past 12 months. Design, Setting, and Participants: This nationally representative cross-sectional analysis included a randomly selected subset of 12th-grade students in 27 US states who participated in the Monitoring the Future Study in-school survey during February to June 2023. Exposures: Self-reported sex, race, ethnicity, and parental education; census region; state-level adult-use (ie, recreational) marijuana legalization (yes vs no); and state-level Δ8-THC policies (regulated vs not regulated). Main Outcomes and Measures: The primary outcome was self-reported Δ8-THC and marijuana use in the past 12 months (any vs no use and number of occasions used). Results: In the sample of 2186 12th-grade students (mean age, 17.7 years; 1054 [48.9% weighted] were female; 232 [11.1%] were Black, 411 [23.5%] were Hispanic, 1113 [46.1%] were White, and 328 [14.2%] were multiracial), prevalence of self-reported use in the past 12 months was 11.4% (95% CI, 8.6%-14.2%) for Δ8-THC and 30.4% (95% CI, 26.5%-34.4%) for marijuana. Of those 295 participants reporting Δ8-THC use, 35.4% used it at least 10 times in the past 12 months. Prevalence of Δ8-THC use was lower in Western vs Southern census regions (5.0% vs 14.3%; risk difference [RD], -9.4% [95% CI, -15.2% to -3.5%]; adjusted risk ratio [aRR], 0.35 [95% CI, 0.16-0.77]), states in which Δ8-THC was regulated vs not regulated (5.7% vs 14.4%; RD, -8.6% [95% CI, -12.9% to -4.4%]; aRR, 0.42 [95% CI, 0.23-0.74]), and states with vs without legal adult-use marijuana (8.0% vs 14.0%; RD, -6.0% [95% CI, -10.8% to -1.2%]; aRR, 0.56 [95% CI, 0.35-0.91]). Use in the past 12 months was lower among Hispanic than White participants for Δ8-THC (7.3% vs 14.4%; RD, -7.2% [95% CI, -12.2% to -2.1%]; aRR, 0.54 [95% CI, 0.34-0.87]) and marijuana (24.5% vs 33.0%; RD, -8.5% [95% CI, -14.9% to -2.1%]; aRR, 0.74 [95% CI, 0.59-0.94]). Δ8-THC and marijuana use prevalence did not differ by sex or parental education. Conclusions and Relevance: Δ8-THC use prevalence is appreciable among US adolescents and is higher in states without marijuana legalization or existing Δ8-THC regulations. Prioritizing surveillance, policy, and public health efforts addressing adolescent Δ8-THC use may be warranted.

How have cannabis use and related indicators changed since legalization of cannabis for non-medical purposes? Results of the Canadian Cannabis Survey 2018-2022.

BACKGROUND: Cannabis use for non-medical purposes was legalized and regulated in Canada through the Cannabis Act in October 2018. This paper examined trends in use of cannabis for non-medical purposes and related indicators from pre- to post-legalization in Canada (2018-2022). METHODS: Data from 5 years of the Canadian Cannabis Survey, an annual web-based survey administered to Canadians 16 years of age or older, were used in the analysis (n2018=12,952; n2019=11,922; n2020=10,821; n2021=10,733; n2022=10,048). Cannabis measures include questions about use, types of products, sources, risk perceptions and beliefs, and exposure to public education campaigns and health warnings. Adjusted logistic regression models tested differences in outcomes over time. RESULTS: Past 12-month cannabis consumption increased among Canadians from 22 % in 2018 to 27 % in 2022 (AOR=1.41;99 % CI:1.28-1.54). Similarly, daily/almost daily (DAD) consumption increased from 5 % in 2018 to 7 % in 2022 (AOR=1.36;99 % CI:1.16-1.59). Consumption of dried flower, hash/kief, and concentrates/extracts (e.g., wax, shatter, budder) decreased since 2018, whereas consumption of edibles, beverages and vape pens/cartridges increased (p < 0.001). Legal purchasing increased from 4 % in 2018 to 69 % in 2022, while accessing cannabis through social and illegal sources decreased over time (p < 0.001). CONCLUSION: More Canadians are reporting cannabis consumption since legalization and regulation of cannabis for non-medical purposes, continuing a pre-existing trend despite an increase in awareness of the risks of consuming cannabis. Trends in product use indicate a transition from dried flower and concentrates/extracts towards consumption of cannabis foods, drinks and vape pens/cartridges. The legal market is increasingly displacing the illicit cannabis market in Canada.

Uneven effects of twenty years of Chile's cannabis policy implementation in cannabis onset.

BACKGROUND: In Chile, Laws 19366 and 20000, implemented in 1995 and 2005 respectively, regulated and sanctioned cannabis' personal use, cultivation and trafficking. METHODS: We use thirteen biannual cross-sectional national surveys data from 1994 to 2018 to examine the effect of Laws 19366 and 20000-using the rate of individuals incarcerated per 100000 population due to drug-related crimes as proxy-on the age of onset of cannabis use over time. We estimate the effect of these policies using a mixed proportional hazards framework that models the transition to first cannabis use in 47,832 individuals aged 12-21. RESULTS: Overall, changes in these laws did not affect the transition to first cannabis use. However, increases in the rate of individuals incarcerated were associated with decreases on the age of onset of cannabis use in females and individuals living in affluent neighborhoods or in specific regions. CONCLUSION: We find no evidence of cannabis policy changes affecting the age of onset of cannabis use across all individuals aged 12-21. Policy effects associated with decreases in cannabis onset age in females and individuals from affluent neighborhoods or specific regions can be explained by using theoretical frames that recognize specific dynamics of cannabis supply and demand.

Individual differences in legal and illicit cannabis purchasing behaviour in British Columbia, Canada: Findings from a 2021 cross-sectional survey.

BACKGROUND: Despite thousands of licensed cannabis retail stores operating across Canada, there remains a significant illicit cannabis market. Some cannabis users continue to buy cannabis from dealers, illicit stores, and/or illicit online retailers. METHODS: Data are from the 2021 British Columbia Cannabis Use Survey. Respondents (n = 8473) were 19 years or older, lived in British Columbia at the time of the survey, and reported using cannabis in the past 12 months. RESULTS: Buying cannabis from all types of illicit sources was more common among younger cannabis users, those who use cannabis more frequently and started using cannabis before the age of 17 (vs. 19 or older), and among those who co-use cannabis with other drugs. Specifically, buying cannabis from a dealer was more common among men, those with lower educational attainment, and those who seek the lowest prices when buying cannabis. In contrast, those using cannabis for medical (vs. non-medical) purposes were more likely to report getting cannabis from illicit retail stores, while buying cannabis from illicit websites was more common among people who use edible cannabis products. CONCLUSION: Consistent with other studies, younger and more frequent cannabis users were more likely to report buying cannabis from illicit sources. However, these findings suggest there is significant heterogeneity among those who buy cannabis from different types of illicit sources, which should be carefully considered when developing policies and strategies aimed at encouraging consumers to transition to legal sources.

Social Norms for Cannabis Use After Nonmedical Legalization in Canada.

INTRODUCTION: Social norms play an important role in cannabis use; however, there is little evidence on how social norms change in jurisdictions that legalize cannabis. This study examined trends in social norms before and after legalization of nonmedical cannabis in Canada in 2018. METHODS: Data are from the International Cannabis Policy Study, a series of cross-sectional surveys conducted annually with Canadian respondents aged 16-65 years. Analyses were conducted in 2023 and included data from 58,045 respondents across 4 waves: the year immediately before legalization (2018) and 3 post-legalization waves (2019-2021). Regression models examined trends in injunctive norms (perceived approval of cannabis) and comfort in using cannabis in six different social contexts, adjusting for cannabis use frequency, medical authorization, and sociodemographic covariates. RESULTS: Perceived social approval of cannabis use and comfort using cannabis in different social contexts was highest among males, frequent cannabis consumers, and those who reported medical authorization (p<0.05 in all cases). No changes in perceived approval were observed across years, except a temporary decrease in 2020 versus 2018 (OR=0.87, 95% CI=0.80, 0.95). Modest increases in comfort of using cannabis in 6 different social contexts were observed in 2019 (ß=0.10, p=0.001), 2020 (ß=0.10, p=0.001), and 2021 (ß=0.12, p<0.001) versus in 2018. CONCLUSIONS: Social norms have remained relatively stable after nonmedical legalization in Canada, with only modest increases in comfort of using cannabis in different social settings. The findings may reflect widespread cannabis use in Canada prior to nonmedical legalization in 2018 as well as comprehensive restrictions on promotion and advertising.

Legalización del consumo de cannabis recreativo en adultos y problemas de salud mentales / Legalization of recreational cannabis use in adults and mental health problems

Los problemas de salud mental hacen parte de las enfermedades no trasmisibles y se les atribuye, con otras enfermedades asociados al bienestar, hasta un 21 % de las muertes mundiales. Por ello, es necesario analizar y establecer la relación riesgo/beneficio de políticas relacionadas con la salud mental, caso de la legalización del consumo de cannabis recreativo en adultos. El cannabis es la droga “ilícita” de mayor consumo en los países occidentales, en esencia por incrementar la sociabilidad y la euforia. En la última década, varios países han promulgado normas orientadas a legalizar la comercialización de cannabis recreativo en adultos. En este sentido, existe controversia del efecto de este tipo de iniciativas, en el porcentaje de personas que consumen esta sustancia y en la salud de los mismos. Sin embargo, se podría esperar que este tipo de iniciativas favorezca un aumento en el porcentaje de personas que consumen esta sustancia. El aumento del consumo de marihuana puede favorecer una mayor prevalencia de problemas de salud mental, incluyendo psicosis y esquizofrenia. Se acepta la existencia de una asociación entre consumo de cannabis y psicosis (incluyendo esquizofrenia). En este marco, reconociendo los beneficios de las políticas de legalización del consumo de cannabis recreativo en adultos, orientadas a superar el enfoque prohibicionista y a buscar la reducción del daño, es conveniente evaluar y definir el efecto de las mismas. Además, estas iniciativas se deben acompañar de programas informativos y educativos, orientados a sintetizar los riesgos del consumo, incluyendo, la dependencia y problemas de salud mentales. (AU)

Mental health problems are included in the non-communicable diseases and together to other problems associated with well-being, they are attributed up to 21 % of global deaths. Therefore, it is necessary to analyze and establish the risk/benefit ratio of policy related to mental health, for example, in the case of the legalization of recreational cannabis use in adults. Cannabis is the most widely used “illicit” drug in Western countries, essentially because it increases sociability and euphoria. In the last decade, several countries have endorsed policies aimed at legalizing the commercialization of recreational cannabis in adults. In this sense, there is controversy about the effect of this type of policy on the percentage of people who consume this substance and on their health. However, it could be expected that this type of initiative will improve the percentage of people who consume this substance. Increased marijuana use may lead to a higher prevalence of mental health problems, including psychosis and schizophrenia. The existence of an association between cannabis use and psychosis (including schizophrenia) is accepted. In this framework, recognizing the benefits of policies to legalize the use of recreational cannabis in adults, advancing from a drug prohibition approach to one focused on harm reduction, it is convenient to evaluate and define the effect of this type of policies. Also, this kind of policies should be linked to informative and educational programs to clarify the risks of consumption, including, dependence and mental health problems. (AU)

Factors Associated with Initiating Cannabis Use After Legalization in Canada: A Cross-Sectional Study.

Background: Cannabis use has increased since the Government of Canada legalized nonmedical use in October 2018. We investigated demographic factors associated with initiating cannabis use after legalization. Materials and Methods: We used data from the 2018 and 2019 National Cannabis Survey and constructed multivariable regression models. Respondents' data were weighted and bootstrapped. We report relative measures of association as adjusted odds ratios (ORs) and absolute measures of association as adjusted risk increases (RIs). Results: Among the 58,195 households surveyed, 28,566 provided complete data (49%) and our weighted analysis represented 27,904,258 Canadians aged ≥ 15 years. Approximately one in five Canadians endorsed use of cannabis (19.8%), predominantly for nonmedical (9.5%) or combined medical and nonmedical (5.8%) reasons. Those who initiated cannabis use in the past 3 months (1.9%) were more likely to be younger (25-34 years vs. ≥ 65 years; adjusted OR 1.7, 95% confidence interval [CI] 1.1-2.8; adjusted RI 1.1%, 95% CI 0.1-2.0%), endorse poor to fair versus good to excellent physical health (adjusted OR 2.0, 95% CI 1.3-3.1; adjusted RI 1.7%, 95% CI 0.3-3.1%), and reside outside of Quebec (adjusted OR 1.4, 95% CI 1.1-2.0; adjusted RI 0.1%, 95% CI 0.6-1.1%). The 1% of Canadians who endorsed initiating use of cannabis due to legalization were more likely to reside outside of Quebec (adjusted OR 1.9, 95% CI 1.1-3.2; adjusted RI 0.5%, 95% CI 0.2-0.9%). Conclusion: Canadians initiating cannabis use after nonmedical legalization were likely to be younger and endorse worse physical health, and half of those using cannabis reported therapeutic use. Stricter policies, lower social acceptance, and less availability of cannabis in Quebec appear to have curtailed initiation of use after legalization.

Impacto de la legalización del consumo recreativo del cannabis / Impact of the legalisation of recreational cannabis use

En los últimos años se han producido importantes cambios legislativos en numerosos países respecto al consumo de cannabis con fines medicinales y/o recreativos, que han facilitado su accesibilidad. Actualmente, Uruguay, Canadá y algunos estados de EE.UU. han legalizado el consumo recreativo, aplicando distintos modelos legislativos. El objetivo de la presente revisión es analizar los efectos que ha tenido la legalización del cannabis recreativo sobre su consumo y sus consecuencias. En general, las evidencias indican que la legalización se ha asociado a un descenso en el precio, mayor concentración de THC (potencia), mayor diversidad de presentaciones para su consumo, una menor percepción de riesgo y un incremento en el consumo en adultos y de forma moderada en adolescentes (aunque sea ilegal el consumo para ellos), así como un aumento de las consecuencias adversas derivadas del consumo en la salud pública. Se ha producido un descenso en los arrestos relacionados con el consumo, pero el mercado ilegal sigue utilizándose de forma habitual. No se ha detectado un incremento de la demanda de tratamiento por este consumo. Por el momento, estos cambios legislativos no han conseguido alcanzar sus objetivos principales que eran suprimir el mercado ilegal y proteger a los grupos más vulnerables, mientras que, por el contrario, parecen implicar un incremento de algunos aspectos negativos asociados al consumo de cannabis. Sin embargo, teniendo en cuenta que la mayoría de estos cambios legislativos han entrado en vigor hace relativamente poco tiempo, se requiere un periodo de seguimiento mayor para poder extraer conclusiones definitivas. (AU)

In recent years, there have been important legislative changes in many countries regarding the use of cannabis for medicinal and/or recreational purposes, which have facilitated access to it. Uruguay, Canada and some of the US states are the only jurisdictions that have legalised recreational consumption, applying different legislative models. The aim of this review is to analyse the effects that the legalisation of recreational cannabis has had on its use and its consequences. In general, the evidence accumulated to date indicates that the legalisation of cannabis has been associated with a decrease in the price of the substance, higher concentration of THC (potency), greater diversity of presentations for consumption, lower risk perception and an increase in consumption in adults and moderately in adolescents (even though it is illegal for them to consume), as well as an increase in the adverse consequences derived from cannabis consumption on public health. There has been a decrease in drug-related arrests, but the illegal market continues to be frequently used. No increase in the demand for treatment due to cannabis consumption has been detected. Therefore, these legislative changes have so far failed to achieve their main objectives, which were to suppress the illegal market and protect the most vulnerable groups, while on the contrary, they seem to imply an increase in some of the negative aspects associated with cannabis consumption. However, taking into account that most of these legislative changes have entered into force relatively recently, a longer follow-up period is required to be able to draw definitive conclusions. (AU)

A Decision 85 Years in the Making.

On October 6, 2022, President Biden announced that he is taking steps to pardon those convicted of simple marijuana possession at the federal level and reconsider the classification of cannabis as a Schedule I substance. At the same time, Congress is working to pass legislation to streamline research in the cannabis space. These efforts signal that federal marijuana laws that have been in place for the past 85 years have created a multitude of problems, including barriers to research, and the federal government is finally considering decisions to create change.