Cannabis-related Harms Research Articles

Changes in the incidence of cannabis-related disorders after the Cannabis Act and the COVID-19 pandemic in Québec, Canada

BackgroundThe Canadian Cannabis Act (CCA, implemented in October 2018) and the COVID-19 pandemic (April 2020) might have contributed to cannabis-related harms in Québec, known for its stringent cannabis legal framework. We explored changes in incidence rates of cannabis-related disorders (CRD) diagnoses associated with these events in Québec. MethodsWe utilized linked administrative health data to identify individuals aged 15 year+ newly diagnosed with CRD during hospitalizations, emergency, and outpatients clinics across Québec, from January 2010 and March 2022 (147 months). Interrupted time-series analyses (ITSA) assessed differences (as percentage changes) in sex- and age-standardized, and sex-stratified, monthly incidence rates (per 100,000 population) attributed to the CCA and the COVID-19 pandemic, compared to counterfactual scenarios where pre-events trends would continue unchanged. ResultsThe overall monthly mean rates of incident diagnoses nearly doubled from the pre-CCA period (1.56 per 100,000 population) to the COVID-19 pandemic period (3.02 per 100,000 population). ITSA revealed no statistically significant level or slope changes between adjacent study periods, except for a decrease in the slope of incidence rates among males by 1.84 % (95 % CI −3.41 to −0.24) during the COVID-19 pandemic compared to the post-CCA period. During the post-CCA period, the trends of incidence rates in the general and male populations grew significantly by 1.22 % (95 % CI 0.08 to 2.35) and 1.44 % (0.04 to 2.84) per month, respectively. Similarly significant increases were observed for the general and female populations during the COVID-19 pandemic, with monthly rates rising by 1.43 % (95 % CI 0.75 to 2.12) and 1.75 % (95 % CI 0.13 to 3.37), respectively. These increases more than doubled pre-CCA rates. ConclusionsThe incidence rates of CRD diagnoses across Québec appears to have increased following the implementation of the CCA and during the COVID-19 pandemic. Our findings echo public health concerns regarding potential cannabis-related harms and are consistent with previous Canadian studies.

Trends in cannabis use in New Jersey: Effects of COVID-19 and cannabis legalization.

With the legalization of cannabis in New Jersey on April 21, 2022, including the licensing of cannabis dispensaries, concerns have arisen about potential adverse events related to cannabis use. Here, we explore temporal trends and risk factors for cannabis-related harm in both adult and pediatric cannabis-related visits at a tertiary care academic institution. We performed a retrospective chart review and temporal trend analysis via the electronic health record from May 1, 2019 to October 31, 2022, covering 2 years before, and 6 months after, cannabis legalization in New Jersey. The pediatric charts identified were analyzed for root causes of adverse events, and changes in the frequency of specific unsafe practices since cannabis legalization were tracked. We found that adult cannabis ED-related visits significantly increased during the COVID-19 pandemic and remained higher than pre-pandemic levels for the remainder of the study periods, without a significant change upon legalization. Pediatric rates of cannabis-related ED visits did not vary significantly during the study period. The vast majority of visits for children aged 0-12 years were related to accidental cannabis exposures-often a household member's edibles-whereas most visits for older children stemmed from intentional cannabis use. This project highlights the unintended consequences of wider cannabis access in New Jersey. Notably, cannabis use increased even before its legalization, presumably in response to the COVID-19 pandemic and its attendant mental health effects. Rates of cannabis use disorder and its highlight of other concurrent psychiatric disorders are important topics for both clinicians and lawmakers to consider.

A survey of educator perspectives toward teaching harm reduction cannabis education.

Substance use is common among youth which can adversely affect youth health. Despite the legalization of cannabis in Canada and much of the United States, there is a lack of harm reduction cannabis education in schools. In addition, educators may not feel prepared to teach students about cannabis. A cross-sectional survey explored educator perceptions toward teaching harm reduction substance use education to students in grades 4-12. Data analysis included descriptive statistics to evaluate demographic variables, ANOVAs to identify subgroup differences, and inductive thematic analysis to establish themes from open-ended responses. From the sample of 170 educators, the majority were female (77%) and worked as classroom teachers (59%). Ninety-two percent of educators felt harm reduction was an effective approach to substance use education, and 84% stated that they would feel comfortable teaching cannabis harm reduction education to students. While 68% of educators believed they would be able to recognize if a student was under the influence of cannabis, only 39% felt certain about how to respond to student cannabis use, and just 8% felt that their current teacher training allowed them to intervene and prevent cannabis-related harms. Most educators (89%) expressed interest in harm reduction training, particularly interactive training (70%) and instructor-led lessons (51%). Online curriculum resources were preferred by 57%. Responses differed by gender and age group, with females of any age and educators under 40 reporting greater support of harm reduction approaches and more interest in training. Educators expressed considerable support for harm reduction substance use education, but many felt unprepared to address this topic with students. The findings identified a need for educator training on harm reduction substance use education, so that educators can help students make informed choices around substance use, thereby promoting youth health and safety.

Preferences of Young Adults With Psychosis for Cannabis-Focused Harm Reduction Interventions: A Cross-Sectional Study: Préférences des jeunes adultes souffrant de psychose pour les interventions de réduction des méfaits axées sur le cannabis : une étude transversale.

Cannabis use is common in people with early-phase psychosis (EP) and is associated with worse treatment outcomes. Few targeted interventions for cannabis use behaviour in this population exist, most focusing on abstinence, none focusing on harm reduction. Many people with EP will not seek treatment for their cannabis use with current therapeutic options. Understanding preferences for cannabis-focused harm reduction interventions may be key to improving outcomes. This study aimed to determine preferences of young adults with EP who use cannabis for cannabis-focused harm reduction interventions. Eighty-nine young adults across Canada with EP interested in reducing cannabis-related harms were recruited. An online questionnaire combining conventional survey methodology and two unique discrete choice experiments (DCEs) was administered. One DCE focused on attributes of core harm reduction interventions (DCE 1) and the second on attributes of boosters (DCE 2). We analysed these using mixed ranked-ordered logistic regression models. Preference questions using conventional survey methodology were analysed using summary statistics. Preferred characteristics for cannabis-focused harm reduction interventions (DCE 1) were: shorter sessions (60 min vs. 10 min, odds ratio (OR): 0.72; P < 0.001); less frequent sessions (daily vs. monthly, OR: 0.68; P < 0.001); shorter interventions (3 months vs. 1 month, OR: 0.80; P < 0.01); technology-based interventions (vs. in-person, OR: 1.17; P < 0.05). Preferences for post-intervention boosters (DCE 2) included opting into boosters (vs. opting out, OR: 3.53; P < 0.001) and having shorter boosters (3 months vs. 1 month, OR: 0.79; P < 0.01). Nearly half of the participants preferred to reduce cannabis use as a principal intervention goal (vs. using in less harmful ways or avoiding risky situations). Further research is required to see if technology-based harm reduction interventions for cannabis featuring these preferences translate into greater engagement and improved outcomes in EP patients.

Cannabis Use Behaviors and Related Harms among Adults in Thailand by Sex Assigned at Birth and Age Groups

Objective: The objectives of this study were to describe: 1) cannabis use behaviors; 2) self-reported cannabis-related harms and harmful behaviors among adults in Thailand, stratified by sex (assigned at birth) and age groups.Material and Methods: A nationally-representative survey among adults in Thailand in May 2023 was conducted. Data using descriptive statistics with sampling weight adjustment was analyzed.Results: Among the study participants (n=2,191 participants), approximately 15% of the participants were current cannabis users (estimated number: 7.5 million people aged 20 or over nationwide). Former and current users reported recreation or other non-medical purposes as the primary purposes of use (93% combined). Ingestion was the most common method of cannabis use. Male participants were more likely than female participants in all age groups to report using smoked cannabis. The most common harmful was riding a motorcycle after having used cannabis, although virtually no participants reported road accidents after same-day cannabis use.Conclusion: This study's data provided basic information for relevant stakeholders. However, the lack of detailed information, the potential influence of social desirability, and the limited temporal generalizability should be considered in the interpretation of this study’s findings.

Effect of a selective personality-targeted prevention program on 7-year illicit substance related outcomes: A secondary analysis of a cluster randomized controlled trial

BackgroundThis study evaluated the efficacy of the selective personality-targeted PreVenture program in reducing cannabis and stimulant use over a 7-year period spanning adolescence and early adulthood. MethodsA cluster randomized controlled trial was conducted in 14 Australian schools. Schools were randomized to PreVenture, a brief personality-targeted selective intervention, comprising two 90-minute facilitator-led sessions delivered one week apart, or a control group (health education as usual). Only students who scored highly on one of four personality traits (anxiety sensitivity, negative thinking, impulsivity, sensation seeking) were included. Students completed online self-report questionnaires between 2012 and 2019: at baseline; post-intervention; 1-, 2-, 3-, 5.5- and 7-years post-baseline. Outcomes were past 6-months cannabis use, stimulant use (MDMA, methamphetamine or amphetamine) and cannabis-related harms. ResultsThe sample comprised 438 adolescents (Mage=13.4 years; SD=0.47) at baseline. Retention ranged from 51% to 79% over the 7-years. Compared to controls, the PreVenture group had significantly reduced odds of annual cannabis-related harms (OR=0.78, 95% CI=0.65–0.92). However, there were no significant group differences in the growth of cannabis use (OR=0.84, 95% CI=0.69–1.02) or stimulant use (OR=1.07, 95% CI=0.91–1.25) over the 7-year period. ConclusionsPreVenture was effective in slowing the growth of cannabis-related harms over time, however owing to missing data over the 7-year trial, replication trials may be warranted to better understand the impact of the PreVenture intervention on cannabis and stimulant use among young Australians. Alternative implementation strategies, such as delivering the intervention in later adolescence and/or providing booster sessions, may be beneficial.

Threaten, Distract, and Discredit: Cannabis Industry Rhetoric to Defeat Regulation of High-THC Cannabis Products in Washington State.

Washington State legislators have attempted to regulate high delta-9-tetrahydrocannabinol (THC) cannabis to reduce cannabis-related harms. Historically, industry actors of other health-compromising products have influenced governments' adoption of evidence-based regulation policies. A better understanding of the industry rhetoric can be used by public health advocates to develop counterarguments and disseminate alternative narratives that protect the public's health. We analyzed the arguments used by cannabis industry actors opposing regulations to de-incentivize the availability and use of high-THC products in Washington State. We analyzed 41 testimonies transcribed from 33 cannabis industry actors in 3 public bill hearings and one legislative work session that occurred between 2020 and 2023. Using a deductive thematic analysis, informed by industry actors' arguments opposing regulation of alcohol, tobacco, and high-sugar beverages, we developed a codebook to analyze and identify themes within cannabis industry rhetorical strategies. We identified three main rhetorical strategies used by cannabis industry actors to oppose THC content regulation: threaten, distract, discredit. The most frequently used rhetorical strategy was threats to economic benefits, public health, and the will of the people. The other two most apparent strategies were distracting from the bill's focus by introducing a tangential topic and discrediting the science that supported regulation of cannabis products with high THC concentration or its advocates. Cannabis industry actors have leveraged several arguments used by industry actors of other health-compromising products to undermine initiatives to advance public health. They have also adapted rhetoric from other industries to the unique conditions of the cannabis regulatory landscape.

Identifying policy options to regulate high potency cannabis: A multiple stakeholder concept mapping study in Washington State, USA

BackgroundCannabis legalization in some U.S.A. states has catapulted the mass production of concentrates, with tetrahydrocannabinol (THC) concentrations ranging from 50-90%. A major public health concern is that these products will increase cannabis-related harms such as use disorders, psychotic symptoms, and accidental poisonings. This paper describes and contextualizes the results of a study requested by the WA State Legislature to understand perspectives of WA stakeholders on the topic. MethodsConcept Mapping (CM), a mixed-methods research approach that supports people-centered policy decisions was utilized. The goal of the study was to explore stakeholders’ concern levels and support of policies to address the availability of high THC cannabis products. For analysis purposes, stakeholders were categorized into three groups: community, professionals, and cannabis advocates. ResultsCM generated an inventory of policy ideas for regulating high-potency cannabis from a variety of stakeholders. Notably, stakeholders from community and professional groups supported environmental policy changes such as such as taxation, increasing minimum age for high concentration cannabis products, and advertising prohibition. Meanwhile, cannabis advocates (mostly industry actors) opposed taxation per THC content, proposed lowering taxes, and supported policies with low population impact such as educating parents, teachers, and youth. ConclusionSupport for regulating high concentration THC products varied by stakeholder group. Consistent with how other health compromising industries have historically acted, cannabis industry stakeholders rejected regulation of their products. Future studies should explore non-cannabis industry stakeholders’ willingness to work towards minimizing the influence of the cannabis industry in policy development processes to assure public health regulations prevail.

Risk and protective factors for cannabis use among young people - a population based survey

Abstract Background Cannabis is the most commonly used illicit substance in Ireland and globally, with its use most likely to occur in adolescence when the developing brain is more vulnerable to cannabis-related harm. This study aims to ascertain the prevalence of and determine the risk and protective factors for cannabis use among adolescents in the North East of Ireland. Methods This study is a cross-sectional, secondary analysis of the 2021 Planet Youth survey. The population comprised a sample of 4404 adolescents aged 15-16 in Cavan, Monaghan and North Dublin. The outcome of interest was cannabis use in the last 30 days. Independent variables were selected a priori following a literature review. Associations between cannabis use and the independent variables were explored using logistic regression. Results The prevalence of current cannabis use among study participants was 7.3%. The odds of cannabis use were higher among current alcohol users (aOR 2.68, CI 1.79-4.02), smokers (aOR 3.17, CI 2.18-4.60), e-cigarette users (aOR 2.72, CI 1.87-3.96), adolescents who did not perceive its use as harmful (aOR 2.24, CI 1.51-3.32), felt their parents were not against cannabis (aOR 3.71, CI 2.43-5.66), had cannabis-using peers (aOR 9.81, CI 5.76-16.71) or felt peer pressure to use cannabis (aOR 1.91, CI 1.09-3.33). Low parental supervision was associated with higher odds of cannabis use. There was no association between gender and cannabis use. Conclusions This study identified five risk factors and three protective factors associated with cannabis use which can be targeted by policymakers when designing drug prevention strategies.

Emerging adult perceptions of higher-risk cannabis consumption behaviours

BackgroundEmerging adults have the highest cannabis consumption rates in Canada and are among the most vulnerable to cannabis-related harms. Since certain cannabis consumption behaviours carry greater risks of harm, the Lower-Risk Cannabis Use Guidelines (LRCUG) provide harm reduction strategies. To address a critical gap in the literature, the current study examined emerging adults’ awareness of the guidelines and perceptions of higher-risk cannabis consumption behaviours identified within the LRCUG.MethodsEmerging adults (N = 653) between the ages of 18–25 years were recruited from across Canada. Participants were presented with five vignettes depicting a character’s cannabis consumption behaviours. Each vignette focused on a unique aspect of the character’s consumption (frequency, polysubstance use, family history of mental illness, method of consumption, and potency). Participants were randomly assigned to one of three conditions within each of the five vignettes that were altered to capture varying levels of risk (e.g. weekly, almost daily, or daily consumption). Following each vignette, participants were asked to respond to four items relating to overall risk of harm, cognitive health, physical health, and mental health.ResultsParticipants perceived: (1) frequent consumption to be associated with greater risks than less frequent consumption; (2) simultaneous consumption of cannabis and tobacco as being associated with higher risk of harm, yet no difference between simultaneous consumption of cannabis and alcohol or cannabis consumption alone; (3) consuming cannabis with a family history of psychosis or substance use disorder as being associated with greater overall risk than consumption with no family history; (4) smoking and vaping cannabis as associated with more risk than ingesting edibles; and (5) higher-potency THC-dominant strains as being associated with more risk than lower-potency CBD-dominant strains, yet no difference between the two higher-potency THC-dominant strains.ConclusionsWhile emerging adults seemed to appreciate the risks associated with some cannabis consumption behaviours, they had difficulty identifying appropriate levels of harm of other higher-risk behaviours. Through an improved understanding of emerging adult perceptions, effective education campaigns should be designed to improve the awareness of cannabis risks and encourage the uptake of harm reduction awareness and strategies.

Gender influences on cannabis use among treatment-seeking adults: a qualitative study

Background Gender differences in cannabis use, related harms, and in the development and progression of cannabis use disorder have been reported. Better understanding and identifying why these differences exist is important in developing and tailoring prevention and treatment approaches. Methods This qualitative interview study explored influences of gender on cannabis use trajectories. Twenty-three adults (10 cisgender women, 12 cisgender men, 1 non-binary person) who had received treatment for cannabis-related problems were asked about the relationship between their gender and cannabis experiences. Results Reflexive thematic analysis was used to develop five themes. First, many participants seemingly did not perceive a strong relationship between their gender and cannabis use. Second, men’s cannabis use was impacted by masculinity facilitating the initiation and escalation of use, while simultaneously acting as a barrier to seeking treatment. Third, men’s motivations for using cannabis were almost always reported to be recreational, which is likely linked to men’s use being more normative. Fourth, almost all women reportedly used cannabis to cope, especially with mental health problems. Fifth, social relationships and gender dynamics constrained women’s cannabis use, particularly where many felt pressured into seeking treatment due to increased stigma for women who use cannabis. Conclusions Our findings revealed gender differences in cannabis use trajectories, including treatment seeking, barriers, and facilitators, emphasizing the importance of developing gender-specific approaches for reducing cannabis-related harms.

A call for mindfulness-based interventions for cannabis-use disorders

Cannabis use is being increasingly liberalized worldwide, and an increasing prevalence of cannabis-use disorder (CUD) is observed. The few current therapeutic options for CUD are only modestly effective. Mindfulness-based interventions offer promising prospects for the management of substance-use disorders. However, despite proliferating literature on mindfulness and substance use, few studies have explored mindfulness in terms of cannabis use and CUD. There are many possibilities for the implementation of mindfulness-based interventions for cannabis use reduction, especially for younger users, who are more vulnerable to cannabis-related harms. Accordingly, large controlled trials are needed to reliably assess the potential of such interventions.

Perceived risk of harm for different methods of cannabis consumption: A brief report

BackgroundEmerging adults’ (EAs; ages 18–25) perceived risk of cannabis-related harms has decreased in recent decades, potentially contributing to their high prevalence of cannabis consumption. With the changing cannabis policy and product landscape, it is critical to understand perceived risk related to different consumption methods (e.g., smoking, dabbing). We examined differences in cannabis risk perceptions by method and consumption patterns. MethodsEAs recruited from an emergency department (N=359, 71.3% female, 53.5% Black) completed assessments on individual characteristics, cannabis/other substance use, and perceived risk of cannabis-related harm for four different methods (smoking, vaping, dabbing, ingestion) and two use frequencies (occasional, regular). Analyses examined associations between variables of interest and three mutually exclusive groups: no cannabis use, smoking-only, and multiple/other methods. ResultsForty-two percent of EAs reported no past 3-month cannabis use, 22.8% reported smoking only, and 35.1% reported consumption via multiple/other methods. Among all participants, the methods and frequency with the largest number of EAs endorsing any perceived risk from cannabis were dabbing and vaping cannabis regularly; smoking occasionally had the smallest number of EAs endorsing perceived risk. A greater proportion of EAs in the no use group viewed vaping cannabis regularly as having the most risk (63.6%), whereas the largest proportion of EAs in the smoking-only (64.6%) and multiple/other methods (47.2%) groups perceived dabbing regularly as having the most risk. ConclusionsThis work shows that EAs vary in perceptions of risk across methods of cannabis use and can inform potential directions for public health and policy efforts.

Do Sex Differences and Risk Perception Affect Cannabis Exposure? Results from a Sample of Current Cannabis Users from the European Web Survey on Drugs

AbstractThe rates of cannabis use have been narrowing between sexes over the past decade, and there are sex differences in the perception of cannabis use-related risks, yet it remains unexamined whether sex and risk perception interact to predict cannabis consumption levels. We aimed to examine for the first time how sex, risk perception, and their interaction affect cannabis consumption, accounting for age, alcohol use, mode of administration, education, employment status, and country via general linear mixed models. We conducted the European Web Survey on Drugs in 16 countries from 2016 to 2018. People who used cannabis at the time of the study included 6500 males and 2921 females, with a median age of 22 years. There was no risk perception-by-sex interaction effect on cannabis consumption. Greater past-month cannabis dosage in grams and frequency (days used/past month) were reported by males and by persons who reported having a perception of no risk and of a slight risk versus a moderate-to-high-risk perception. The findings may inform discussions on public health messaging aimed at alleviating cannabis-related harms in males and females who use cannabis.

Characterizing heterogeneity among people who use cannabis for medicinal reasons: A latent class analysis of a nationally representative Canadian sample.

Many individuals who use cannabis report doing so for medicinal reasons. Few studies have explored heterogeneity within this population, which may be important to inform targeted interventions. This study used latent class analysis to identify subgroups of people who use cannabis for medicinal reasons and their sociodemographic and cannabis-risk-related correlates. Data were drawn from the 2019 Canadian Alcohol and Drugs Survey, which is a representative survey of Canadians ages 15 years and older. Data from 814 individuals reporting past-year use of cannabis for medicinal or mixed medicinal and non-medicinal reasons were included. Latent class analysis was conducted with forms of cannabis used, cannabis use frequency, concurrent non-medicinal cannabis use, and the medical conditions and symptoms cannabis was used to manage as indicators. Four distinct latent classes of medicinal cannabis use were identified: a non-daily cannabis flower for mental health and sleep class (39.56% of the sample), a non-daily cannabis flower for pain class (26.41% of the sample), a non-daily cannabis oil for physical health class (20.15% of the sample), and a daily multi-form cannabis for mental health and non-medical reasons class (13.88% of the sample). Sociodemographic factors and risk level for cannabis-related harms were associated with latent class membership. Results of this study reveal considerable heterogeneity among people reporting medicinal cannabis use and suggest that the distinct patterns of cannabis use behaviors and motives observed may be important for understanding risk for cannabis-related harms in this population. Findings underscore a need for harm reduction interventions tailored toward specific patterns of medicinal cannabis use.

Direct and indirect effects of cannabis risk perceptions on cannabis use frequency

Background Perceived risk of harm associated with cannabis use has decreased in recent decades, particularly among emerging adults who show the highest prevalence of use. Cannabis-related protective behavioral strategies (PBS) are associated with lower cannabis use and fewer consequences; however, individuals who perceive using cannabis as low risk may use cannabis PBS less often. Therefore, using cross-sectional data, we examined the associations between perceived risk of harm associated with cannabis use, cannabis PBS, and cannabis use frequency. Method Participants were 146 emerging adults between the ages of 18–25 (56.2% female) who reported consuming cannabis at least 3 times/week and completed measures of past-month cannabis use, past three-month use of cannabis PBS, and perceived risk of harm associated with cannabis use. Path analyses examined direct and indirect effects of perceived risk of cannabis-related harm on cannabis frequency through cannabis PBS. Results Most (66.4%) participants reported no perceived risk of harm associated with occasional cannabis use, whereas 30.1% reported no perceived risk of harm associated with regular cannabis use. Findings indicated a significant indirect effect between perceived risk of harm and cannabis use frequency through cannabis PBS, b = −10.23, SE = 3.80, 95% CI [−17.67, −2.80], p = .007. Conclusions Among emerging adults who consume cannabis regularly, findings suggest that a greater perceived risk of cannabis-related harm is associated with decreased cannabis use frequency via increased use of cannabis PBS. Although future analyses evaluating causal mechanisms are needed, these findings have clinical implications for harm reduction interventions focused on cannabis use. Trial Registration: The parent study from which these data were drawn was preregistered at Clinical Trials.Gov NCT04187989.

Prices of flower and resin in cannabis social clubs: Analyses of register data from 220,000 collections.

Cannabis social clubs (CSC) are community-based non-profit organisations that aim to minimise cannabis-related harm for their members. This contribution seeks to: (i) compare the cost of cannabis flower and resin in CSCs to the national average retail price on the illegal market; and (ii) identify possible quantity discounts for cannabis flower and resin distributed to members of CSCs. Routine data from four CSCs located in Barcelona, Spain, contained information on n = 220,465 collections of cannabis resin and flower (0.01-39 g per collection). The costs for 1 g of cannabis flower and resin per collection were determined. The mean national prices on illicit cannabis were obtained from Spanish police reports. On average, members paid 6.19€ for 1 g flower (median: 6€; interquartile range: 6-7€) and 8.54€ for 1 g resin (median: 7€; interquartile range: 6-9€), with less variations for flower than for resin. Compared to the national average, prices appeared to be higher for cannabis products distributed in CSCs, but comparisons were limited by a lack of data on the variation of national prices. For resin, doubling the quantity was associated with a 20.7% (95% confidence interval 20.4-21.2%; p < 0.001) fee discount. Cannabis in CSCs may be more costly than the estimated national average for the illicit market. No meaningful price discount could be observed for flower but for resin. Pricing policies pursued by CSCs may help to disincentivise consumption of larger amounts but may also bar socioeconomically disadvantaged users from accessing safer alternatives than the illegal market.

Measuring cannabis quantities in online surveys: A rapid review and proposals for ways forward.

Cannabis use quantities are relevant for determining cannabis-related harms. This research aims to provide an overview of the available methods to assess quantities through self-report. A rapid review of various strategies to collect information on cannabis use quantities through self-report. Two independent literature searches resulted in n=38 studies included for review. A total of n=14 studies employed methods for collecting cannabis use quantities that are not suitable for online surveys (e.g., rolling a fake joint). Of the remaining n=24 studies with items that are suitable for online surveys, the quantity assessment was performed in three different ways. The data collection was either carried out by asking (a) for the total number of joints (i.e., crude joint method), (b) for the total weight (i.e., crude weight method), or (c) for specific products separately, for example, for the amount of flower and resin (i.e., product-specific method). In only n=8 studies, cannabis use quantities were ascertained by providing visual aids (e.g., illustration of various amounts of flower). The crude joint method and the product-specific method are the two most promising methods to collect information on cannabis use quantities. Using visual aids may potentially improve the accuracy of those methods.

Strictly regulated cannabis retail models with state control can provide lessons in how jurisdictions can regulate THC.

Strictly regulated cannabis retail models with state control can provide lessons in how jurisdictions can regulate THC.

Impact of Canada's cannabis legalisation on youth emergency department visits for cannabis-related disorders and poisoning in Ontario and Alberta, 2015-2019.

Although there is momentum towards legalising adult recreational cannabis use worldwide, the extent of youth cannabis-related harm associated with legalisation is still uncertain. The current study aimed to assess whether the initial implementation of Canada's cannabis legalisation (via the Cannabis Act) on 17 October 2018 might be associated with youth harm, as assessed by emergency department visits for cannabis-related disorders/poisoning. We used Ontario and Alberta, Canada emergency department data from 1 April 2015 to 31 December 2019. We identified all cannabis-related disorders/poisoning (ICD-10 CA: F12.X, T40.7) emergency department visits of youth (n= 13,615), defined as patients younger than the minimum legal cannabis sales age (18 years, Alberta; 19 years, Ontario). Seasonal Autoregressive Integrated Moving Average (SARIMA) models were employed to assess the impact of legalisation on weekly counts of cannabis-related harms. The final SARIMA intervention (step) parameter indicated a post-legalisation increase of 14.7 (95% confidence interval [CI] 5.0; 24.3, p < 0.01) weekly youth cannabis-related disorder/poisoning presentations to Ontario/Alberta emergency department settings, equivalent to an increase of 20.0% (95% CI 6.2%; 33.9%). There was no evidence of associations between cannabis legalisation and comparison series of youth alcohol, opioid or appendicitis emergency department episodes. Our findings require replication and extension but are consistent with the possibility that the implementation of the Cannabis Act was associated with an increase in youth cannabis-related presentations to Ontario/Alberta emergency departments.