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

Young adult retail purchases of cannabis, product category preferences and sales trends in California 2018-21: Differences compared with older adults

AIMS

The aim of this study is to identify cannabis products according to their appeal among young adults and measure product sales trends.

DESIGN, SETTING AND PARTICIPANTS

This was a retrospective comparative study using point-of-sale data from licensed recreational cannabis retailers that include buyer age with birth year entered by retailers, set in California, USA. Cannabis purchases by young adults (aged 21-24, GenZ) were compared with older adults (age 25+) over 4 years (2018-21).

MEASUREMENTS

Sales for six cannabis product categories were analyzed using a commercial data set with imputations and a raw data set. Age-appeal metrics were dollar and unit sales to young adults, and dollar and unit share ratios (young adults/older adults), where a share ratio of 100 denotes age-appeal comparability. A product category was considered more young-adult appealing than others if its mean on a metric was at least one standard deviation above the grand mean across all product categories.

FINDINGS

Flower (cannabis plant material) and vapor pen appealed to young adults based on absolute dollar sales, dominating young-adult spending compared with other cannabis products (37.24 and 31.83%, respectively). Vapor pen and concentrate appealed to young adults based on dollar share ratios of 152, meaning these products comprised a 52% greater share of young-adult cannabis spending relative to older-adult spending (31.83/20.97% and 10.47/6.88%, respectively). Less appealing to young adults were pre-roll, edible/beverage and absorbable products (tincture/sublingual, capsule and topical). Flower showed the largest dollar sales growth (B = +$3.50 million/month), next to vapor pen (B = +$1.55 million/month). Vapor pen tied for highest growth in the percent of product dollars from the largest package size (B = +0.85%/month) and showed the steepest price decline (B = -0.53 price per gram/month).

CONCLUSIONS

In California, USA, from 2018 to 2021, relative to older adults, young adults spent a greater share of their cannabis dollars on vapor pen and concentrate (products with high potency of delta-9-tetrahydrocannabinol).

Use of ENDS devices and modifications to vape cannabis among adolescents and young adults who also vape nicotine

BACKGROUND

Electronic nicotine delivery systems (ENDS) are the most used tobacco product among adolescents and young adults (AYAs) and are increasingly used to vape cannabis. It is unclear what vaping devices and ENDS modifications are used most frequently by AYAs who vape both nicotine and cannabis.

METHODS

AYAs (aged 14-29) reporting ENDS use in the past 30 days were recruited via Qualtrics (N = 1,011). We conducted three multivariable logistic regression models examining differences in likelihood of: 1) vaping cannabis in the past 30 days; 2) mixing cannabis and nicotine liquids; and 3) using nicotine devices to vape cannabis; based on type of vaping device used most often, controlling for age, socio-economic status, gender, race, frequency of ENDS use, and other cannabis use.

RESULTS

40 % (n = 405) of AYAs reported vaping both nicotine and cannabis in the past 30 days. AYAs who used vape pens most often were more likely to have vaped cannabis concentrates in the past 30 days compared to individuals using disposable vapes (aOR = 2.72, 95 %CI = 1.75-4.21, p < 0.001). AYAs who used open systems most often (i.e., vape pens, mods, or e-hookah) were more likely than individuals using closed systems (i.e., disposable vapes, rechargeable pods or cigalikes) to combine nicotine and cannabis e-liquids (aOR = 2.03, 95 %CI = 1.43-2.89, p < 0.001) or use a nicotine device to vape cannabis (aOR = 1.66, 95 %CI = 1.17-2.34, p = 0.005).

IMPLICATIONS

Co-use of cannabis and nicotine via similar devices, particularly vape pens and other open-systems, warrants collaborative regulatory efforts to mitigate co-use of both substances, with a particular need for increased regulation of cannabis vaping products.

Prevalence of Blunt and Hemp Wrap Use Among Young Adults in the United States, 2022

INTRODUCTION

Blunt and hemp wraps, as a means of consuming cannabis, have emerged into the retail space where the prevalence has been increasing since 2017. There is limited epidemiological research on the prevalence of use of these products across the U.S. particularly among young adults who are at greater risk of tobacco and cannabis use.

METHODS

This study draws from a U.S. national representative sample of young adults (n = 1178) captured in May 2022. Respondents participated in an online survey about their use of blunt and hemp wraps. Multinomial regression was used to examine differences in sociodemographic characteristics (gender, race/ethnicity, sexual orientation, educational attainment, and region) in relation to use of each wrap type.

RESULTS

One quarter (22.7%) of young adults reported ever having used a blunt wrap, 3.2% in the past 30-days. One in seven (14.3%) had ever used a hemp wrap, 2.3% in the past 30-days. Non-Hispanic Black young adults were 1.55 and 2.91 times as likely to have ever used blunt or hemp wraps, respectively, compared to non-Hispanic Whites. Similarly, participants who identified as gay or lesbian or bisexual similarly had greater odds of having ever used blunt or hemp wraps. Hispanic young adults were 2.49 times as likely to have used hempwraps compared to non-Hispanic Whites.

CONCLUSION

Blunt and hemp wrap use is prevalent among young adults, particularly among minoritized populations. Continued research and surveillance of use of these products is needed to fully evaluate the impact their use may have on the broader population.

Cannabis Use Variations and Myocardial Infarction: A Systematic Review

Background: Cannabis use is associated with an increased risk of coronary heart disease (CHD), including angina pectoris (AP), and myocardial infarction (MI). However, it is not clear whether cannabis use is an independent risk factor of AP and/or MI, because cannabis is often smoked together with tobacco. We investigated whether cannabis is an independent risk factor of MI and whether this risk is similar in cannabis smokers, cannabis vapers, and those who use cannabis edibles. Methods: A systematic review was performed, according to the PRISMA guidelines and using Medline (PubMed), Embase, and Google Scholar as databases. Results: Twenty-two eligible papers were identified. After adjustment for concurrent tobacco use, cannabis smoking remained significantly associated with incidents of MI, with aORs ranging between 1.03 and 5.24, and particularly high aORs in the younger age group. In never-tobacco smokers, frequent cannabis smoking was also associated with a significant MI risk (aOR = 1.88). Frequent and current cannabis use in any form other than smoking (e.g., vaping, but mostly ingestion) was not associated with a significantly increased cardiovascular risk (frequent use: aOR = 1.00 ns; current use: aOR = 1.31 ns). Conclusions: Like tobacco smoking, cannabis smoking may independently provoke MI. Vaping and ingestion of cannabis might be less harmful, probably because absence of combustion prevents exposure to certain toxins in cannabis smoke, including carbon monoxide.

Clinical guidance for cannabidiol-associated hepatotoxicity: A narrative review

There is increasing evidence that cannabidiol (CBD) use is associated with clinically significant liver enzyme (LE) elevations and drug-induced liver injury (DILI). The proportion of LE elevations and DILI events reported in the literature meet the Council for International Organizations of Medical Sciences' (CIOMS) classification of a common adverse drug reaction. However, these potential adverse events are unknown to many clinicians and may be overlooked. The increasing use of CBD for both medical and non-medical use necessitates clear direction in the diagnosis and management of CBD-associated hepatotoxicity. To our knowledge, no such clinical guidance currently exists. For people presenting with elevated LEs, CBD use should be screened for and be considered in the differential diagnosis. This narrative review will provide clinicians with guidance in the prevention, detection, and management of CBD-related hepatotoxicity.

Higher substance use is associated with low executive control neural activity and higher inflammation

Individuals with substance use problems show lower executive control and alterations in prefrontal brain systems supporting emotion regulation and impulse control. A separate literature suggests that heightened inflammation also increases risk for substance use, in part, through targeting brain systems involved in executive control. Research on neural and inflammatory signaling in substance use, however, has occurred in parallel. Drawing on recent neuroimmune network models, we used fMRI to examine the relationships between executive control-related brain activity (as elicited by an n-back working memory task), peripheral inflammation, as quantified by inflammatory cytokines and C-reactive protein (CRP), and substance use for the past month in 93 participants [mean age = 24.4 (SD = 0.6)]. We operationalized low executive control as a neural inefficiency during the n-back task to achieve normative performance, as reflected in higher working memory-related brain activity and lower activity in the default mode network (DMN). Consistent with prediction, individuals with low executive control and high inflammation reported more substance use over the past month, controlling for behavioral performance on the n-back, sex, time between assessments, body-mass-index (BMI), and personal socioeconomic status (SES) (interaction between inflammation and working memory-related brain activity, b = 0.210, p = 0.005; interaction between inflammation and DMN, b = -0.219, p < 0.001). Findings suggest that low executive control and high inflammation may be associated with higher substance use. This has implications for understanding psychological, neural, and immunological risk for substance use problems and the development of interventions to target each of these components.

Sex Differences in Response-Contingent Cannabis Vapor Administration During Adolescence Mediate Enduring Effects on Behavioral Flexibility and Prefrontal Microglia Activation in Rats

Introduction: Cannabis is the most used illicit drug in the United States. With many states passing legislation to permit its recreational use, there is concern that cannabis use among adolescents could increase dramatically in the coming years. Historically, it has been difficult to model real-world cannabis use to investigate the causal relationship between cannabis use in adolescence and behavioral and neurobiological effects in adulthood. Materials and Methods: We used a response-contingent vapor administration model to investigate long-term effects of cannabis use during adolescence on the medial prefrontal cortex (mPFC) and mPFC-dependent behaviors in male and female rats. Results: Adolescent (35- to 55-day-old) female rats had significantly higher rates of responding for vaporized Δ9-tetrahydrocannabinol (THC)-dominant cannabis extract (CANTHC) compared with adolescent males. In adulthood (70-110 days old), female, but not male, CANTHC rats also took more trials to reach criterion and made more regressive errors in an automated attentional set-shifting task compared with vehicle rats, thereby indicating sex differences in behavioral flexibility impairments. Notably, sex-treatment interactions were not observed when rats of each sex were exposed to a noncontingent CANTHC vapor dosing regimen that approximated CANTHC vapor deliveries earned by females. No differences were observed in effort-based decision making in either sex. In the mPFC, female (but not male) CANTHC rats displayed more reactive microglia with no changes in myelin basic protein expression or dendritic spine density. Conclusion: Altogether, these data reveal important sex differences in rates of responding for CANTHC vapor in adolescence that may confer enduring alterations to mPFC structure and function and suggest that there may be subtle differences in the effects of response-contingent versus noncontingent cannabis exposure that should be systematically examined in future studies.

Does acute cannabidiol (CBD) use impair performance? A meta-analysis and comparison with placebo and delta-9-tetrahydrocannabinol (THC)

Cannabidiol (CBD) is widely used and believed to be non-intoxicating, lacking acute performance effects (e.g., non-impairing). However, a synthesis of data has not evaluated this. This meta-analysis synthesized data from controlled human laboratory studies that evaluated if acute CBD use impairs performance. Performance on objective and subjective measures of cognitive and psychomotor function were used as markers for potential performance changes and impairment. Studies were identified through systematic database searches. Adult clinical trials measuring acute CBD effects (within 0-8 h of administration) were included. The primary outcome was the peak mean difference in performance measures between CBD and placebo. A secondary analysis utilizing delta-9-tetrahydrocannabinol (Δ9-THC) as a positive control for comparison to CBD was completed. Pooled Hedges' g estimates were calculated using robust variance estimation (RVE) meta-regression. The omnibus RVE meta-analysis indicated a statistically significant, but small effect size (Hedge's g < 0.2) for impaired performance following acute CBD consumption compared to placebo (N = 16 trials, Hedges' g = 0.122, 95% CI: 0.023-0.221, p = 0.019). Measure type was a significant moderator with larger mean differences between CBD and placebo when subjective measures, specifically self-reported sedation, were used versus objective performance tasks (Hedges' gSubjective = 0.288 versus Hedges' gObjective = 0.048). Δ9-THC had a significantly greater magnitude of impairment compared to CBD (N = 8, Hedges' g = 0.416, 95% CI: 0.017-0.816, p = 0.043). In summary, acute CBD consumption was associated with a small increase in subjective ratings of sedation, but no difference from placebo was observed across multiple domains of objectively assessed cognitive or psychomotor performance. These findings suggest that acute CBD alone is unlikely to significantly impair daily functioning or workplace performance.

Associations between Cannabis Consumption Methods and Cannabis Risk Perception

Given diversified cannabis products, we examined associations between cannabis consumption methods and cannabis risk perception of smoking cannabis 1-2 times a week. Using the 2022 U.S. National Survey on Drug Use and Health data (N = 12,796 past-year adult cannabis users; M = 6127 and F = 6669), we used multinomial and binary logistic regression models. Smoking was the most prevalent method, followed by eating/drinking, vaping, and dabbing. One-half of cannabis users reported no perceived risk of smoking cannabis 1-2 times a week, 37.5% perceived slight risk, 9.2% moderate risk, and 2.9% great risk. Those with moderate or great risk perception had a lower likelihood of using 4+ methods of consumption (e.g., RRR = 0.40, 95% CI = 0.20, 0.77 for great risk perception). Any perceived risk was associated with higher odds of edibles/drinks only (e.g., aOR = 2.81, 95% CI = 1.43, 5.54 for great risk perception). Along with medical use and CUD, sociodemographic factors, mental illness, and other substance use were also significant correlates of cannabis consumption methods. Understanding the varying risk perceptions associated with different consumption methods is needed for harm reduction initiatives. More research is needed on cannabis products, particularly edibles/drinks and dabs/concentrates, to better understand the potential risks associated with them.

Changes in modes of cannabis consumption pre- and post-legalization and their correlates among adults in Ontario, Canada: 2017-2022

Background: Despite an increase in the varieties of cannabis products available for consumption, limited evidence is available about the patterns of cannabis consumption methods before and after legalization.Objectives: To examine the changes in modes of cannabis use and their correlates among adults in Ontario, Canada both prior to and following cannabis legalization in 2018.Methods: Data were utilized from the 2017 to 2022 Centre for Addiction and Mental Health's (CAMH) Monitor study, a repeated cross-sectional survey of adults 18 years of age and older (n = 2,665; 56% male). The surveys employed a regionally stratified sampling design using computer-assisted telephone interviews and web surveys. Multinomial regression was performed to examine different modes of cannabis use.Results: The exclusive use of cannabis through ingestion methods increased from 4.0% in 2017 to 16.6% in 2022 (p < .001). However, the exclusive use of inhalation-based cannabis decreased from 49.4% in 2017 to 25.5% in 2022 (p < .001). Relative to inhalation-based modes, adults were about five times more likely to use ingestion-based modes in 2020 [RRR = 4.65 (2.94-7.35)] and 2022 [RRR = 4.75 (2.99-7.55)] than in 2019, after accounting for sociodemographic factors.Conclusions: Ingestion-based cannabis use among adults increased fourfold between 2017 and 2022, a period during which recreational cannabis use was legalized in Canada. The increase was especially evident after the legalization of cannabis edibles.

Prevalence and socio-demographic correlates of multi-modal cannabis use among young adults who currently use cannabis

Cannabis use is common in young adulthood, yet little is known about the prevalence and patterns of multi-modal (i.e., use of more than one mode) cannabis use.

Objective

We aimed to (1) determine the past 30-day prevalence of five modes (smoke, vape, edible, dab, other) of cannabis use, (2) describe the prevalence of multi-modal cannabis use (single vs. dual vs. poly-modal), and (3) identify socio-demographic correlates of multi-modal use among young adults.

Method

Participants were 764 22-30-year-olds who currently used cannabis from Wave 9 (Spring 2019) of the Marketing and Promotions Across Colleges in Texas Project. Participants were 25.11 years old on average (SD = 1.81), 63.6% female, 38.7% identified as non-Hispanic white, 30.6% as Hispanic/Latino, 13.0% as Asian and 9.4% as Black, and 8.2% identified with two or more races or another race/ethnicity. Bivariate analyses and a multinomial regression were used to examine study questions.

Results

Smoking was the most common mode of cannabis use followed by vaping and then edibles. Nearly 43% of participants reported single-modal cannabis use, 33% reported dual-modal use, and 24% reported poly-modal use. Males and those identifying as non-heterosexual were at a greater risk than their counterparts for using multiple modes of cannabis. Participants identifying as Black were at a reduced risk for poly-modal compared to single-modal use.

Conclusion

Multi-modal use is common among young adults who currently use cannabis, indicating a need for universal efforts aimed at all young adults. Tailored interventions aimed toward those at elevated risk for multi-modal use also are needed.

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.

Development and Initial Validation of a Momentary Cannabis Craving Scale Within a Homogeneous Sample of U.S. Emerging Adults

Given the popularity and ease of single-item craving assessments, we developed a multi-item measure and compared it to common single-item assessments in an ecological momentary assessment (EMA) context. Two weeks of EMA data were collected from 48 emerging adults (56.25% female, 85.42% White) who frequently used cannabis. Eight craving items were administered, and multilevel factor analyses were used to identify the best fitting model. The resulting scale's factors represented purposefulness/general desire and emotionality/negative affect craving. Convergent validity was examined using measures of craving, cannabis use disorder symptoms, frequency of use, cannabis cue reactivity, cannabis use, negative affect, and impulsivity. The scale factors were associated with cue-reactivity craving, negative affect, impulsivity, and subfactors of existing craving measures. For researchers interested in using a single item to capture craving, one item performed particularly well. However, the new scale may provide a more nuanced assessment of mechanisms underlying craving.

Cannabis Use in Germany

BACKGROUND

The federal government of Germany is planning to liberalize the recreational cannabis market for adults. We aimed to collect key baseline data on frequency of use, routes of administration, and co-use of cannabis and inhaled nicotine or tobacco products in the population.

METHODS

Based on data from a national survey of 9644 people aged >14 years, we analyzed self-reported use of cannabis in the past 12 months and preferred route of administration (single choice: smoked with tobacco; smoked without tobacco; inhaled without tobacco; consumed with food; consumed in another form).

RESULTS

The prevalence of past-year cannabis use was 4.6% (95% CI [4,2; 5,1%]), with higher rates among 14-24- (11.4%) and 25-39-year-olds (8.2%) as well as among co-users of inhaled nicotine or tobacco products, particularly waterpipe users (27.0%). Smoking cannabis with or without tobacco was the preferred route of administration, reported by 92.4% (95% CI [89,6; 94,6%]). It was most frequently reported by 14-24-year-olds and by co-users of inhaled nicotine or tobacco products.

CONCLUSION

Smoking remains the predominant form of using cannabis-especially among younger users, who are at greatest risk of cannabis-related consequences. The true prevalence of cannabis use may have been underestimated in our study, however, as not all participants answered the questions on cannabis. Nevertheless, preventive and harm reduction efforts are needed to reduce the harm from using cannabis. Continuous monitoring is required to evaluate the effects of the forthcoming law changes in Germany.

Marijuana use disorder among adults with functional disabilities-A US population-based cross-sectional study

BACKGROUND AND OBJECTIVES

Recent studies suggest a growing trend in marijuana use, compared to a stable prevalence of marijuana use disorder among US adults over the first 15 years of the 21st century. This study investigated the recent patterns of marijuana use disorder among people with disabilities (PWD).

METHODS

We extracted a nationally representative sample (N = 209,058) from the 2015-2019 National Survey on Drug Use and Health data set and examined associations by functional disability status (any disability, disability by type, and number of disabling limitations) with marijuana use disorder using a series of independent multivariable logistic regression models. We also performed trend analyses during the study period.

RESULTS

The prevalence of marijuana use disorder (from 1.7% to 2.3%) increased significantly among PWD between 2015 and 2019 (p-trend < .001). PWD were significantly more likely to report marijuana use disorder (odds ratio [OR], 1.37, 95% confidence interval [CI], 1.24-1.52) than people without disability (PWoD). Those with cognitive limitation only (OR, 1.78, 95% CI, 1.53-2.06) and ≥2 limitations (OR, 1.29, 95% CI, 1.10-1.51) were more likely to report marijuana use disorder than PWoD.

DISCUSSION AND CONCLUSIONS

PWD had a consistently higher prevalence of marijuana use disorder than PWoD. Additionally, the level of risk for marijuana use disorder varied by disability type and number of disabling limitations.

SCIENTIFIC SIGNIFICANCE

Our study provided new nuance on disparities in marijuana use disorder between PWD and PWoD and further revealed the varied risks for marijuana use disorder across different disability statuses.

Impact of Cannabis Legalization on Adolescent Cannabis Use

Because of substantial limitations in available national data, such as inconsistencies among surveys and small sample sizes, the increased prevalence of cannabis use among adolescents since recreational legalization has not been directly observed. Nevertheless, both usage frequency and product potency have significantly increased, alongside alternative routes of delivery to smoking, such as vaping cannabis. Moreover, certain populations may be especially vulnerable to the effects of legalization. Regardless of differing state-level cannabis legalization status, the adverse consequences of cannabis on youth have clear negative impacts on mental health, medical symptoms, educational outcomes, and increased risk of addiction to other substances.

Sex Differences in Plasma, Adipose Tissue, and Central Accumulation of Cannabinoids, and Behavioral Effects of Oral Cannabis Consumption in Male and Female C57BL/6 Mice

BACKGROUND

Cannabis edibles are an increasingly popular form of cannabis consumption. Oral consumption of cannabis has distinct physiological and behavioral effects compared with injection or inhalation. An animal model is needed to understand the pharmacokinetics and physiological effects of oral cannabis consumption in rodents as a model for human cannabis edible use.

METHODS

Adult male and female C57BL/6 mice received a single dose of commercially available cannabis oil (5 mg/kg Δ⁹-tetrahydrocannabinol [THC]) by oral gavage. At 0.5, 1, 2, 3, and 6 hours post exposure, plasma, hippocampus, and adipose tissue were collected for THC, 11-OH-THC, and THC-COOH measures.

RESULTS

We report delayed time to peak THC and 11-OH-THC concentrations in plasma, brain, and adipose tissue, which is consistent with human pharmacokinetics studies. We also found sex differences in the cannabis tetrad: (1) female mice had a delayed hypothermic effect 6 hours post consumption, which was not present in males; (2) females had stronger catalepsy than males; (3) males were less mobile following cannabis exposure, whereas female mice showed no difference in locomotion but an anxiogenic effect at 3 hours post exposure; and (4) male mice displayed a longer-lasting antinociceptive effect of oral cannabis.

CONCLUSIONS

Oral cannabis consumption is a translationally relevant form of administration that produces similar physiological effects as injection or vaping administration and thus should be considered as a viable approach for examining the physiological effects of cannabis moving forward. Furthermore, given the strong sex differences in metabolism of oral cannabis, these factors should be carefully considered when designing animal studies on the effects of cannabis.

Parallel trajectories of vaping and smoking cannabis and their associations with mental and physical well-being among young adults

BACKGROUND

Vaping and smoking are common modes of using cannabis (THC) among young adults, but little is known about how patterns of cannabis vaping and smoking unfold over time or how using one or both types of products may differently affect mental and physical well-being. This study examines parallel processes of cannabis vaping and smoking over 5 years and mental and physical outcomes in a sample of young adults.

METHODS

Annual surveys were conducted between 2016 and 2022 with a mostly California-based cohort of 2428 young adults. Parallel process growth mixture models examined trajectories of past-month frequency of cannabis vaping and smoking from ages 20 - 25. Classes were extracted based on parallel trajectories of vaped and smoked product use. Models assessed differences in self-reported mental (anxiety, depression) and physical (ailments, subjective overall) well-being outcomes in young adulthood across classes, adjusting for demographic characteristics and mental and physical well-being at pre-baseline (average age 19).

RESULTS

Four cannabis vaping/smoking classes emerged: low use of cannabis (84.7%), decreasing smoking, low-moderate vaping (7.1%), stable moderate smoking, decreasing vaping (4.6%), and rapid increasing dual use (3.4%). Classes were similar on physical well-being indicators in young adulthood. The rapid increasing dual use class showed higher anxiety and depressive symptoms compared to other classes.

CONCLUSION

Progression to higher frequency of both vaping and smoking cannabis in young adulthood may contribute to poorer mental well-being compared to other use patterns. Targeted efforts to reduce dual vaping and smoking in young people who use cannabis may be needed.

Theory-based correlates of cannabis use and intentions among US and Israeli adults: a mixed methods study

BACKGROUND

In the US and Israel, non-medical ('recreational') cannabis use is illegal at the national level; however, use rates are high and decriminalization and legalization is spreading. Thus, theory-based intervention efforts, especially for youth prevention, are crucial.

METHODS

This mixed-methods study of adults in the US (n = 1,128) and Israel (n = 1,094) analyzed: 1) cross-sectional survey data (Fall 2021) to identify theory-based correlates (risk perceptions, social norms) of past-month cannabis use, next-year use intentions, and intentions to use in the home or among children if non-medical cannabis was legal, using multivariable regression; and 2) qualitative interviews regarding perceptions of cannabis policies and use (US n = 40, Israel n = 44).

RESULTS

16.7% reported past-month use; 70.5%, 56.3%, and 82.6% indicated "not at all likely" regarding next-year use and use in the home and among children if legal. Lower perceived risk and greater social norms were associated with past-month use, greater use intentions, and greater intentions to use in the home or among children. Past-month use was more prevalent among US (vs. Israeli) participants (22.0% vs. 11.2%); however, in multivariable regression controlling for past-month use, being from Israel was associated with greater use intentions (next-year; in the home/among children). Qualitative themes indicated: concerns about use (e.g., increasing use, health risks, driving-related risks) and legalization (e.g., impact on society/economy, marketing), and perceived benefits of use (e.g., medical) and legalization (e.g., access/safety, economic, individual rights).

CONCLUSIONS

Despite differences in cannabis perceptions and use across countries, perceived risk and social norms are relevant intervention targets regardless of sociopolitical context.

N-acetylcysteine for smoking cessation among dual users of tobacco and cannabis: Protocol and rationale for a randomized controlled trial

BACKGROUND

Tobacco and cannabis co-use is a growing public health problem. The synergistic effects of cannabis and nicotine on neurobiological systems that mediate reward and shared environmental cues reinforcing use may make tobacco smoking cessation more difficult. N-acetylcysteine (NAC), an FDA-approved medication and over-the-counter supplement, has shown promise in animal studies and randomized controlled trials (RCTs) in reducing tobacco and cannabis craving and use. NAC's potential efficacy in treating addiction may be attributable to its central nervous system effects in reducing excessive glutamatergic activity, oxidative stress, and inflammation. To date, no RCT has examined NAC for smoking cessation among dual users of tobacco and cannabis.

METHOD

In a double-blind, placebo-controlled RCT, we will examine NAC for smoking cessation among dual users of tobacco and cannabis. Sixty adult cigarette-cannabis co-users are randomized to receive NAC 3600 mg per day or placebo over 8 weeks. Participants in both groups receive 8 weekly cognitive behavioral therapy sessions addressing smoking cessation and cannabis reduction. Outcomes are assessed at Weeks 0, 4, 8, and 12. Primary aims are to determine NAC's efficacy in decreasing cigarette craving, nicotine dependence, and use; and cannabis craving and use. Exploratory aims include examination of changes in neurocognition with NAC and their potential mediational effects on cigarette and cannabis use outcomes.

CONCLUSION

Results will inform smoking cessation treatment among dual users of tobacco and cannabis.

CLINICALTRIALS

gov Identifier: NCT04627922.

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

BACKGROUND

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.

METHOD

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.

RESULTS

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.

CONCLUSIONS

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.

Sex differences in adolescent cannabis vapor self-administration mediate enduring effects on behavioral flexibility and prefrontal microglia activation in rats

Cannabis is the most used illicit drug in the United States. With many states passing legislation to permit its recreational use, there is concern that cannabis use among adolescents could increase dramatically in the coming years. Historically, it has been difficult to model real-world cannabis use to investigate the causal relationship between cannabis use in adolescence and behavioral and neurobiological effects in adulthood. To this end, we used a novel volitional vapor administration model to investigate long-term effects of cannabis use during adolescence on the medial prefrontal cortex (mPFC) and mPFC-dependent behaviors in male and female rats. Adolescent (35-55 day old) female rats had significantly higher rates of responding for vaporized Δ9-tetrahydrocannabinol (THC)-dominant cannabis extract (CANTHC) compared to adolescent males. In adulthood (70-110 day old), female, but not male, CANTHC rats also took more trials to reach criterion and made more regressive errors in an automated attentional set-shifting task compared to vehicle rats. Similar set-shifting deficits were observed in males when they were exposed to a non-contingent CANTHC vapor dosing regimen that approximated CANTHC self-administration rates in females. No differences were observed in effort-based decision making in either sex. In the mPFC, female (but not male) CANTHC rats displayed more reactive microglia with no significant changes in myelin basic protein expression or dendritic spine density. Together, these data reveal important sex differences in rates of cannabis vapor self-administration in adolescence that confer enduring alterations to mPFC structure and function. Importantly, female-specific deficits in behavioral flexibility appear to be driven by elevated rates of CANTHC self-administration as opposed to a sex difference in the effects of CANTHC vapor per se.

Impact of Cannabis Legalization on Adolescent Cannabis Use

Because of substantial limitations in available national data, such as inconsistencies among surveys and small sample sizes, the increased prevalence of cannabis use among adolescents since recreational legalization has not been directly observed. Nevertheless, both usage frequency and product potency have significantly increased, alongside alternative routes of delivery to smoking, such as vaping cannabis. Moreover, certain populations may be especially vulnerable to the effects of legalization. Regardless of differing state-level cannabis legalization status, the adverse consequences of cannabis on youth have clear negative impacts on mental health, medical symptoms, educational outcomes, and increased risk of addiction to other substances.

Nationally Representative Surveys on Cannabis Use Lack Product Details Relevant to Public Health

Objectives

Many annual, nationally representative US surveys that assess cannabis use do not collect information on product characteristics despite varying health risks and benefits. Capitalizing on a rich dataset of primarily medical users, the purpose of this study was to describe the degree of potential misclassification in clinically relevant cannabis use measures when primary mode of use is recorded but not product type.

Methods

Analyses consider user-level data from the Releaf App™ database on product types, consumption modes, and potencies in a non-nationally representative sample of 26,322 cannabis administration sessions occurring in 2018, across 3,258 users. Proportions, means, and 95% confidence intervals were calculated and compared across products and modes.

Results

Primary consumption modes were smoking (47.1%), vaping (36.5%), and eating/drinking (10.4%), with 22.7% of users reporting multiple modes of use. Moreover, mode of use did not signify a single product type: users reported vaping both flower (41.3%) and concentrates (68.7%). Of those who smoked cannabis, 8.1% reported smoking concentrates. Concentrates averaged 3.4 times higher tetrahydrocannabinol (THC) potency and 3.1 times higher cannabidiol (CBD) potency than flower.

Conclusions

Cannabis consumers employ multiple consumption modes, and product type cannot be inferred from mode of use. With THC potencies markedly higher in concentrates, these findings underscore the importance of including information on cannabis product types and mode of use in surveillance surveys. Clinicians and policymakers need these data to inform treatment decisions and assess cannabis policies' implications for population health.

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.

Vaping preferences of individuals who vaporise dry herb cannabis, cannabis liquids and cannabis concentrates

In 2019 an estimated 200 million people aged 15-64 used cannabis, making cannabis the most prevalent illicit substance worldwide. The last decade has seen a significant expansion in the cannabis vaporiser market, introducing cannabis vaporisation as a common administration method alongside smoking and ingestion. Despite reports of increased prevalence of cannabis vaporisation there has been little research into the use of these devices. To remedy the current dearth of data in this area this study utilised an anonymous online survey of individuals who self-reported past cannabis vaporisation. The respondents (N = 557) were predominantly young (<35 years) and male. Most (91.4 %) stated they had ever vaped dry herb cannabis, 59.1 % reported vaporisation of cannabis oil or liquids, and 34.0 % reported vaporisation of cannabis concentrates. This study identifies the types of vaporisation devices (including brands and models) employed by cannabis vapers, as well as the vaporisation temperatures and puff durations commonly used for dry herb, cannabis liquids and cannabis concentrates. To the best of our knowledge, this is the first time the usual operating temperatures of these vaporisation devices and user specific consumption patterns such as puff duration have been reported for cannabis vaping. This information will allow for a more realistic understanding of patterns of recreational use and improve experimental conditions in research settings to reflect the user's context.

Cannabis smoke condensate induces human gingival epithelial cell damage through apoptosis, autophagy, and oxidative stress

OBJECTIVES

This study aims to investigate the effects of cannabis smoke condensate (CSC) on the adhesion, growth, and signaling pathways of human gingival epithelial cells.

DESIGN

The effects of CSC on cell shape and adhesion, and viability were evaluated after 30 min, 60 min, 2 h, and 24 h of exposure using microscopic observation, cell metabolic activity, and lactate dehydrogenase activity assays. The effects of CSC on cell apoptosis, necrosis, autophagy, and oxidative stress were determined through flow cytometry, while apoptotic and autophagic gene expression were identified via an RT2-PCR array. Phosphorylated signaling pathway proteins were measured using flow cytometry.

RESULTS

CSC deregulated gingival epithelial cell shape and adhesion, decreased cell viability, and increased lactate dehydrogenase release. Its toxic effects included apoptosis, autophagy, and oxidative stress. Moreover, it modulated seven specific apoptotic and six autophagic genes. Furthermore, it decreased phosphorylation in signaling proteins, such as STAT5, ERK12, P38, and nuclear factor κB.

CONCLUSIONS

CSC has notable adverse effects on gingival epithelial cells. This finding indicates that cannabis smoke could impair gingival epithelial cell innate immune function, leading to gingivitis and periodontitis. Oral health professionals may need to document observed modifications in the oral cavity of patients who smoke cannabis and consider these potential changes during clinical care.