Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state

Emissions from Heated Terpenoids Present in Vaporizable Cannabis Concentrates

Vaporizable cannabis concentrates (VCCs) consumed as a liquid (vaping) or a waxy solid (dabbing) are becoming increasingly popular. However, their associated emissions and impacts have not been fully described. Mixtures containing different proportions of 12 VCC terpenoids and high MW compounds were heated at 100-500 °C inside a room-sized chamber to simulate emissions. Terpenoids, thermal degradation byproducts, and ultrafine particles (UFPs) were quantified in the chamber air. Air samples contained over 50% of emitted monoterpenes and less than 40% of released sesquiterpenes and terpene alcohols. Eleven degradation byproducts were quantified, including acrolein (1.3-3.9 μg m^-3) and methacrolein (2.0 μg m^-3). A large amount of UFPs were released upon heating and remained airborne for at least 3 h. The mode diameter increased from 80 nm at 100 °C to 140 nm at 500 °C, and particles smaller than 250 nm contributed to 90% of PM_1.0. The presence of 0.5% of lignin, flavonoid, and triterpene additives in the heated mixtures resulted in a threefold increase in the particle formation rate and PM_1.0 concentration, suggesting that these high-molecular-weight compounds enhanced aerosol inception and growth. Predicted UFP emission rates in typical consumption scenarios (6 × 10¹¹-2 × 10¹³ # min^-1) were higher than, or comparable with, other common indoor sources such as smoking and cooking.

Trends and Characteristics of Manufactured Cannabis Product and Cannabis Plant Product Exposures Reported to US Poison Control Centers, 2017-2019

This cross-sectional study examines reports of cannabis exposure at US poison control centers for trends in patient and product characteristics, stratified by manufactured cannabis products and plant materials.

Lessons from the public health responses to the US outbreak of vaping-related lung injury

AIM

To describe an outbreak of lung injuries in 2019 among people who vaped in the United States (type of injuries, people afflicted, substances vaped and cause of the injuries) and to analyse critically the regulatory responses of public health authorities and the media reporting of the outbreak.

METHODS

Case studies of the reporting of the e-cigarette or vaping product use associated lung injury (EVALI) outbreak. We examined data on the number of cases of lung injury provided by the US Centers for Disease Control (CDC), public advice on the causes of the outbreak provided by the CDC and the Food and Drug Administration (FDA), major media reports of the outbreak and proposed regulatory responses by governments in the United States, Australia and the United Kingdom.

RESULTS

The CDC initially suggested that the cause of the outbreak was nicotine vaping because the outbreak followed a large increase in nicotine vaping among US adolescents. Case-control studies revealed that the majority of cases had vaped illicit cannabis oils that were contaminated by vitamin E acetate. The CDC's public advice and the media were slow to report the evidence on the role of cannabis vaping. Popular government regulatory proposals-bans on sales of nicotine flavours and vaporizers-were based on the assumption that nicotine vaping was the cause of the outbreak.

CONCLUSIONS

Media reporting in the United States, Australia and the United Kingdom of the US Centers for Disease Control's analysis of the causes of the e-cigarette or vaping product use associated lung injury outbreak contributed to regulatory over-reactions to nicotine vaping by the public health community.

Changes in delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) concentrations in cannabis over time: systematic review and meta-analysis

BACKGROUND AND AIMS

Cannabis products with high delta-9-tetrahydrocannabinol (THC) concentrations carry an increased risk of addiction and mental health disorders, while it has been suggested that cannabidiol (CBD) may moderate the effects of THC. This study aimed to systematically review and meta-analyse changes in THC and CBD concentrations in cannabis over time (PROSPERO registration: CRD42019130055).

DESIGN

Embase, MEDLINE® and Epub Ahead of Print, In-Process and Other Non-Indexed Citations and Daily, Global Health, PsycINFO and Scopus were searched from inception to 27/03/2019 for observational studies reporting changes in mean THC and/or CBD concentration in cannabis over at least three annual time points. Searches and extraction were conducted by two independent reviewers. Random effects meta-regression models estimated annual changes in THC and CBD for each product within each study; these estimates were pooled across studies in random effects models.

RESULTS

We identified 12 eligible studies from the USA, UK, Netherlands, France, Denmark, Italy and New Zealand. For all herbal cannabis, THC concentrations increased by 0.29% each year (95% CI: 0.11, 0.47), P < 0.001 based on 66 747 cannabis samples from eight studies, 1970-2017. For cannabis resin, THC concentrations increased by 0.57% each year (95% CI: 0.10, 1.03), P = 0.017 based on 17 371 samples from eight studies, 1975-2017. There was no evidence for changes in CBD in herbal cannabis [-0.01% (95% CI: -0.02, 0.01), P = 0.280; 49 434 samples from five studies, 1995-2017] or cannabis resin [0.03% (95% CI: -0.11, 0.18), P = 0.651; 11 382 samples from six studies, 1992-2017]. Risk of bias was low apart from non-random sampling in most studies. There was evidence of moderate to substantial heterogeneity.

CONCLUSIONS

Concentrations of delta-9-tetrahydrocannabinol (THC) in international cannabis markets increased from 1970 to 2017 while cannabidiol (CBD) remained stable. Increases in THC were greater in cannabis resin than herbal cannabis. Rising THC in herbal cannabis was attributable to an increased market share of high-THC sinsemilla relative to low-THC traditional herbal cannabis.

CBD, a precursor of THC in e-cigarettes

The use of cannabidiol (CBD) in electronic cigarettes is widespread. Previously, it was reported that CBD is partly transformed to THC in case smoking as a cigarette, however, the pyrolysis of this compound has not been assessed extensively. The aim of our study was to investigate the effect of temperature on the composition of pyrolysis products of CBD. The experiments were performed in the typical operating temperature range of e-cigarettes (250–400 °C) and at 500 °C under both inert and oxidative conditions, and the pyrolysis products were identified and quantified by GC–MS. Depending on the temperature and atmosphere, 25–52% of CBD was transformed into other chemical substances: Δ⁹-THC, Δ⁸-THC, cannabinol and cannabichromene were the predominant pyrolysates in both conditions, all formed by cyclization reaction. THC was the main pyrolysis product at all temperatures under both oxidative and inert conditions. Our results point out that CBD in e-cigarettes can be considered as a precursor of THC, thus it bears all the dangers related to this psychoactive compound. Our findings are fundamental contributions to the safety profile of CBD-based e-cigarettes.

Self-administration of inhaled delta-9-tetrahydrocannabinol and synthetic cannabinoids in non-human primates

Cannabis and synthetic cannabinoids are abused in spite of possible adverse health consequences. The current study investigated the reinforcing effects of an ecologically relevant mode of administration (inhalation) of delta-9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, and three synthetic cannabinoids detected in synthetic cannabinoid products (JWH-018, JWH-073, and HU-210) in non-human primates (NHPs). Male and female (N = 4 each) rhesus macaques were trained to inhale warm air via a metal stem to receive a candy reinforcer, an alcohol aerosol vehicle was then paired with the candy. Dose-dependent responding for inhaled aerosols of THC (2.0-16.0 μg/kg/inhalation), JWH-018 (0.2-1.6 μg/kg/inhalation), JWH-073 (2.0-8.0 μg/kg/inhalation), and HU-210 (1.0-8.0 μg/kg/inhalation) was established using a fixed-ratio five schedule of reinforcement and compared to vehicle (alcohol) self-administration. Dose-dependent responding for inhaled heroin (25.0-100.0 μg/kg/inhalation), a known reinforcer in NHPs, was also established. Responding approximated vehicle levels for many drug doses tested, but at least half of the monkeys responded for ≥ one dose of each cannabinoid and heroin above vehicle, with the exception of THC. Drug deliveries calculated as percent vehicle followed a prototypical inverted-U shaped dose-response curve for cannabinoids and heroin except for THC and JWH-018 (in males). Grouped data according to sex demonstrated that peak percent of vehicle reinforcers earned for THC was greater in males than females, whereas peak percent of vehicle reinforcers earned for JWH-018, HU-210, and heroin were greater in females than males. These findings indicate minimal reinforcing effects of CB1 receptor agonists when self-administered by NHPs via aerosol inhalation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cannabis Retail Staff ("Budtenders") Attitudes Towards Cannabis Effects on Health and Experiences Interacting with Consumers - Washington State, USA

Cannabis legalization in Washington State has increased the availability, consumption, and potency of cannabis products for adults. Public health education promoting safe use for adult consumers has lagged behind these trends. This study assesses the potential of cannabis retail workers (budtenders) to engage in responsible use education with adult consumers at point of sale. Focus groups explored how budtenders perceive their professional role, including educating consumers about cannabis over intoxication, storage, and risks of use before driving and during pregnancy. Transcripts were analyzed to develop a coding scheme, which was then applied with an iterative review by the research team. Budtenders identified three main professional roles: creating a good experience for customers; being compliant with the state law and regulations, and educating customers on products. Budtenders did not believe their job involved discussing use during pregnancy or while driving or safe storage. They prioritized customers' autonomy over education on these topics, and they did not necessarily consider these behaviors to be harmful. Budtenders are committed to keeping minors outside stores and educating consumers on how to avoid over intoxication and exposure to cannabis contaminants. Future research could build on this to develop point-of-sale education to reduce cannabis use risks.

The frequency distribution of reported THC concentrations of legal cannabis flower products increases discontinuously around the 20% THC threshold in Nevada and Washington state

Background

Cannabis laboratory testing reliability is a scientific and policy challenge in US states with legal cannabis. Greater reported THC concentration yields higher prices, and media reports describe a well-known consumer and dispensary preference for flower products containing a minimum 20% THC content—an economically meaningful but biologically arbitrary threshold. This paper examines the frequency distribution of reported THC concentration in legal cannabis flower products in Nevada and Washington state for unusual shifts around the 20% threshold suggestive of potential manipulation of reported THC results.

Methods

THC concentration test results for 142,000 Chemotype 1 flower products from Washington state between June 2014 and May 2017 and 55,000 flower products from Nevada between December 2017 and January 2020 were analyzed for changes in the frequency distribution around the 20% threshold using the McCrary density test. Analyses were performed among all labs in each state, the highest volume lab in Washington, and two labs in Washington which had their licenses suspended for testing irregularities during the study period.

Results

Comparing just above the 20% THC threshold with just below it, the frequency of test results increased by about 43% in Nevada (z = 15.6, p < 0.001) and by about 17% in Washington (z = 11.0, p < 0.001). In Washington’s highest volume testing lab, frequency increased by only about 1% (z = 0.39, p = 0.70), while it increased by about 47% (z = 12.7, p < 0.001) among the two suspended labs. Subset to those growers which sent products to both sets of labs, frequency of flower products just above the 20% threshold increased by 2% in Washington’s largest lab (z = 0.50, p = 0.62) and by 52% among the two suspended labs (z = 12.8, p < 0.001).

Discussion

There is a statistically unusual spike in the frequency of products reporting just higher than 20% THC in both states consistent with economic incentives for products to contain at least 20% THC. This “bunching” of reported THC levels exists among some, but not all, cannabis testing labs, suggesting that laboratory differences (rather than precise manipulation by growers) drive this potential manipulation in reported THC content. These findings elaborate on prior research highlighting unexplained interlaboratory variation in cannabis testing results and highlight ongoing irregularities with legal cannabis testing.

Conclusion

These findings highlight the need for industry oversight and cautions researchers working with reported cannabis THC concentration data, which may be biased by economic incentives to report higher THC.

Sourcing Cannabis sativa L. by thermogravimetric analysis

Marijuana, dried and ground Cannabis, is the most consumed illicit drug in the world. Many undesirable and risky effects to human health are caused by its use. The medicinal use or legal recreational use of Cannabis has also been rising in many countries. These facts make traceability methodologies increasingly important whether for forensic use, such as drug trafficking eradication, or for quality control purposes of legal medicinal Cannabis. Consequently, the objective of this study was to analyze Cannabis by means of thermogravimetric analysis (TGA) in order to assess the capability of this technique to trace the geographical origin of Cannabis cultivated in Colorado, United States of America. TGA appears to be sensitive enough to detect the degradation/decarboxylation of cannabinoids and terpenes, at least to some extent; also, the degradation of cellulose, hemicellulose and lignin was indicated. Overall, the temperature ranges we analyzed using linear discriminant analysis showed high accuracies, with the 200 to 300 °C and 600 to 700 °C ranges achieving 100% accuracy.

Evaluation of State Cannabis Laws and Rates of Self-harm and Assault

Importance

State cannabis laws are changing rapidly. Research is inconclusive about their association with rates of self-harm and assault. Existing studies have not considered variations in cannabis commercialization across states over time.

Objective

To evaluate the association of state medical and recreational cannabis laws with self-harm and assault, overall and by age and sex, while considering varying degrees of commercialization.

Design, Setting, and Participants

Using a cohort design with panel fixed-effects analysis, within-state changes in claims for self-harm and assault injuries before and after changes in cannabis laws were quantified in all 50 US states and the District of Columbia. Comprehensive claims data on commercial and Medicare Advantage health plan beneficiaries from January 1, 2003, to December 31, 2017, grouped by state and month, were evaluated. Data analysis was conducted from January 31, 2020, to January 21, 2021.

Exposures

Categorical variable that indexed the degree of cannabis legalization in each state and month based on law type (medical or recreational) and operational status of dispensaries (commercialization).

Main Outcomes and Measures

Claims for self-harm and assault injuries based on International Classification of Diseases codes.

Results

The analysis included 75 395 344 beneficiaries (mean [SD] age, 47 [22] years; 50% female; and median follow-up, 17 months [interquartile range, 8-36 months]). During the study period, 29 states permitted use of medical cannabis and 11 permitted recreational cannabis. Point estimates for populationwide rates of self-harm and assault injuries were higher in states legalizing recreational cannabis compared with states with no cannabis laws, but these results were not statistically significant (adjusted rate ratio [aRR] assault, recreational dispensaries: 1.27; 95% CI, 0.79-2.03;self-harm, recreational dispensaries aRR: 1.15; 95% CI, 0.89-1.50). Results varied by age and sex with no associations found except for states with recreational policies and self-harm among males younger than 40 years (aRR <21 years, recreational without dispensaries: 1.70; 95% CI, 1.11-2.61; aRR aged 21-39 years, recreational dispensaries: 1.46; 95% CI, 1.01-2.12). Medical cannabis was generally not associated with self-harm or assault injuries populationwide or among age and sex subgroups.

Conclusions and Relevance

Recreational cannabis legalization appears to be associated with relative increases in rates of claims for self-harm among male health plan beneficiaries younger than 40 years. There was no association between cannabis legalization and self-harm or assault, for any other age and sex group or for medical cannabis. States that legalize but still constrain commercialization may be better positioned to protect younger male populations from unintended harms.

Cannabis use and cannabis use disorder

Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health burdens are less than those of other forms of drug use, but CUD accounts for a substantial proportion of persons seeking treatment for drug use disorders owing to the high global prevalence of cannabis use. Cognitive behavioural therapy, motivational enhancement therapy and contingency management can substantially reduce cannabis use and cannabis-related problems, but enduring abstinence is not a common outcome. No pharmacotherapies have been approved for cannabis use or CUD, although a number of drug classes (such as cannabinoid agonists) have shown promise and require more rigorous evaluation. Treatment of cannabis use and CUD is often complicated by comorbid mental health and other substance use disorders. The legalization of non-medical cannabis use in some high-income countries may increase the prevalence of CUD by making more potent cannabis products more readily available at a lower price. States that legalize medical and non-medical cannabis use should inform users about the risks of CUD and provide information on how to obtain assistance if they develop cannabis-related mental and/or physical health problems.

Association of Recreational Cannabis Legalization With Maternal Cannabis Use in the Preconception, Prenatal, and Postpartum Periods

IMPORTANCE

Recent studies have revealed increases in population-level cannabis use after legalization of recreational cannabis. However, the association of cannabis legalization with maternal cannabis use during important life stages remains unknown.

OBJECTIVE

To investigate the association of legalization of recreational cannabis with maternal cannabis use during the preconception, prenatal, and postpartum periods.

DESIGN, SETTING, AND PARTICIPANTS

This repeated cross-sectional study used state-level data on women who delivered live-born infants in the US from the Pregnancy Risk Assessment Monitoring System from January 2004 to December 2018. Data from 2 states that had legalized recreational cannabis (Alaska and Maine) and 2 states that had not legalized recreational cannabis (New Hampshire and Vermont) were used. Women completed surveys 2 to 6 months after delivery, reporting preconception, prenatal, and postpartum cannabis use.

EXPOSURE

State recreational cannabis legalization.

MAIN OUTCOMES AND MEASURES

The 3 primary outcomes were self-reported cannabis use during the 12 months before pregnancy (preconception), during pregnancy (prenatal), and the 2 to 6 months after pregnancy (postpartum). A difference-in-differences analysis was used to compare changes in the prevalence of maternal cannabis use during each period before and after state legalization of recreational cannabis, controlling for maternal characteristics (age, race/ethnicity, educational level, income, cigarette smoking, and breastfeeding) and state fixed effects. State-specific survey weights were used.

RESULTS

The analytic sample included 23 082 women in the preconception period, 23 859 in the prenatal period, and 26 610 in the postpartum period. In each analysis, most women were married (range among all groups, 63.9%-64.8%), aged 25 to 34 years (preconception, 55.4%; prenatal, 55.9%; postpartum, 56.1%), and had an annual household income less than $50 000 (preconception, 55.7%; prenatal, 56.3%; postpartum, 55.5%). In adjusted analyses, preconception and postpartum cannabis use increased significantly in states that had legalized recreational cannabis compared with states that had not legalized it (preconception risk difference, 0.0457 [95% CI, 0.0013-0.0900]; P = .04; postpartum risk difference, 0.0539 [95% CI, 0.0259-0.0818]; P < .001). The risk difference for prenatal cannabis use was not significant (0.0070; 95% CI, -0.0120 to 0.0260; P = .47).

CONCLUSIONS AND RELEVANCE

In this repeated cross-sectional study, recreational cannabis legalization was associated with changes in maternal cannabis use before and after pregnancy. The findings suggest that future studies should undertake an interdisciplinary approach to maximize benefit and application of findings to future public health, health care, and policy sectors.

Cannabinoids and the Adolescent Patient: A Pragmatic Guide for Pediatric Practitioners

Primary care and emergency medicine practitioners frequently care for adolescents with acute or chronic effects of cannabinoids. Cannabinoid epidemiology and pharmacology are changing as new laws and regulations, new products, and new means of delivery are rapidly developed. A grasp of basic cannabinoid terminology, which is also constantly shifting, helps clinicians obtain histories and discuss diagnoses, treatments, and outcomes with their patients. The ability to identify and treat cannabinoid-associated illnesses such as cannabinoid hyperemesis syndrome, withdrawal syndrome, and acute intoxication with synthetic cannabinoids can reduce morbidity. Research on neurodevelopmental, cognitive, and psychological effects of adolescent cannabinoid use helps clinicians to have informed conversations with their patients, while providing anticipatory guidance. This article is designed with busy clinicians in mind and highlights the practical information necessary to provide care to their adolescent patients. [Pediatr Ann. 2021;50(2):e57-e64.

Assessing New Zealand's Cannabis Legalization and Control Bill: prospects and challenges

BACKGROUND

Few countries have developed detailed legislative proposals for legalizing cannabis. New Zealand recently released the Cannabis Legalization and Control Bill (CLCB) that will be the subject of a referendum in September 2020.

AIMS

To assess the CLCB, drawing on emerging evidence from cannabis legalization overseas, public health research on alcohol and tobacco and the attempt to establish a regulated market for 'legal highs' in New Zealand.

DISCUSSION

The CLCB proposes a strictly regulated commercial cannabis market that resembles the Canadian approach, but notably without on-line sales or regional heterogeneity in retail distribution. The objective of the CLCB of lowering cannabis use over time appears at odds with the largely commercial cannabis sector that will focus on expanding sales. The CLCB includes provision for home cultivation and social benefit operators, but it is not clear what priority these operators will receive. A potency cap of 15% tetrahydrocannabinol (THC) for cannabis plants is included, and this is at the high end of black-market cannabis. The proposed progressive product tax based on THC will be challenging to implement. There is no formal minimum price, but rather discretionary powers to raise the excise if the price drops too much. The CLCB includes a comprehensive ban on advertising, but non-conventional on-line promotion will be difficult to suppress. The central government cannabis authority is tasked with developing local retail outlet policies. We caution against the temptation to employ an interim regulatory regime following a positive referendum result, because a partially regulated market will expose users to health risks and undermine public support.

CONCLUSIONS

New Zealand's Cannabis Legalization and Control Bill's objective of reducing cannabis use via a commercial market will be challenging to achieve. The bill could be strengthened with formal minimum pricing, lower potency cap and greater clarity concerning social benefit operators and the role of local government.

Acute Effects of Cannabis on Symptoms of Obsessive-Compulsive Disorder

BACKGROUND

Little is known about the the acute effects of cannabis on symptoms of OCD in humans. Therefore, this study sought to: 1) examine whether symptoms of OCD are significantly reduced after inhaling cannabis, 2) examine predictors (gender, dose, cannabis constituents, time) of these symptom changes and 3) explore potential long-term consequences of repeatedly using cannabis to self-medicate for OCD symptoms, including changes in dose and baseline symptom severity over time.

METHOD

Data were analyzed from the app Strainprint® which provides medical cannabis patients a means of tracking changes in symptoms as a function of different doses and strains of cannabis across time. Specifically, data were analyzed from 87 individuals self-identifying with OCD who tracked the severity of their intrusions, compulsions, and/or anxiety immediately before and after 1,810 cannabis use sessions spanning a period of 31 months.

RESULTS

Patients reported a 60% reduction in compulsions, a 49% reduction in intrusions, and a 52% reduction in anxiety from before to after inhaling cannabis. Higher concentrations of CBD and higher doses predicted larger reductions in compulsions. The number of cannabis use sessions across time predicted changes in intrusions, such that later cannabis use sessions were associated with smaller reductions in intrusions. Baseline symptom severity and dose remained fairly constant over time.

LIMITATIONS

The sample was self-selected, self-identified as having OCD, and there was no placebo control group.

CONCLUSIONS

Inhaled cannabis appears to have short-term beneficial effects on symptoms of OCD. However, tolerance to the effects on intrusions may develop over time.

When Cannabis Use Goes Wrong: Mental Health Side Effects of Cannabis Use That Present to Emergency Services

Cannabis use is a modifiable risk factor for the development and exacerbation of mental illness. The strongest evidence of risk is for the development of a psychotic disorder, associated with early and consistent use in youth and young adults. Cannabis-related mental health adverse events precipitating Emergency Department (ED) or Emergency Medical Services presentations can include anxiety, suicidal thoughts, psychotic or attenuated psychotic symptoms, and can account for 25-30% of cannabis-related ED visits. Up to 50% of patients with cannabis-related psychotic symptoms presenting to the ED requiring hospitalization will go on to develop schizophrenia. With the legalization of cannabis in various jurisdiction and the subsequent emerging focus of research in this area, our understanding of who (e.g., age groups and risk factors) are presenting with cannabis-related adverse mental health events in an emergency situation is starting to become clearer. However, for years we have heard in popular culture that cannabis use is less harmful or no more harmful than alcohol use; however, this does not appear to be the case for everyone. It is evident that these ED presentations should be considered another aspect of potentially harmful outcomes that need to be included in knowledge mobilization. In the absence of a clear understanding of the risk factors for mental health adverse events with cannabis use it can be instructive to examine what characteristics are seen with new presentations of mental illness both in emergency departments (ED) and early intervention services for mental illness. In this narrative review, we will discuss what is currently known about cannabis-related mental illness presentations to the ED, discussing risk variables and outcomes both prior to and after legalization, including our experiences following cannabis legalization in Canada. We will also discuss what is known about cannabis-related ED adverse events based on gender or biological sex. We also touch on the differences in magnitude between the impact of alcohol and cannabis on emergency mental health services to fairly present the differences in service demand with the understanding that these two recreational substances may impact different populations of individuals at risk for adverse events.

Extending the Harm to Others Paradigm: Comparing Marijuana- and Alcohol-Attributed Harms in Washington State

Harms attributed to others' alcohol use have been extensively studied in the US and internationally, but no studies have measured harms from others' marijuana use. We utilize data from five cross-sectional waves of a survey series with representative samples of Washington state residents conducted every 6 months from 2014 to 2016, after the legalization of adult use marijuana. Harms attributed to others' drinking and to others' marijuana use included family and financial problems, assault, harassment, and vandalism experiences, and accidents due to impaired drivers. Past year harms attributed to others' marijuana use were reported by 8.4% of the sample, while 21.3% reported alcohol-attributed harms and 4.3% experienced both. Women were more likely to experience harms from either substance. While heavy drinkers were most likely to experience alcohol harms from others' use, frequent marijuana users reported the least harms from others. About three times as many individuals reported harassment, vandalism, or family problems attributed to someone's alcohol use compared to those harms attributed to someone's marijuana use, with a smaller ratio seen for financial trouble and a wider ratio for physical harm. Harms attributed to other's marijuana use in Washington were found to be substantial, but lower than harms from others' drinking.

The Lower-Risk Cannabis Use Guidelines' (LRCUG) recommendations: How are Canadian cannabis users complying?

Canada, alongside other jurisdictions, implemented non-medical cannabis legalization in 2018, partly towards improving public health. Evidence-based 'Lower-Risk Cannabis Use Guidelines' (LRCUG), including recommendations for cannabis users on how to decrease risk-behaviors for harms, have been developed and widely disseminated in Canada since 2017. However, knowledge on users' compliance with the LRCUG is limited. We identified four major Canadian (three national, one provincial) population surveys presenting key data on cannabis-related behaviors: the National Cannabis Survey, Canadian Cannabis Survey, Canadian Tobacco, Alcohol & Drugs Survey, and CAMH Monitor. We scanned each survey for indicator data mapping onto either of the LRCUG's recommendations for the years 2017 to 2019. Relevant indicator data, albeit with varying operationalizations, were found for six of the ten LRCUG's recommendation clusters in at least some of the surveys, and were extracted and summarized. For results, substantial -- but declining -- majorities of users consumed cannabis by smoking, yet with shifts towards other use modes. Between one- to two-in-five users engaged in the risk-behaviors of using high-potency cannabis products, frequent cannabis use and cannabis-impaired driving, respectively. A small proportion of pregnant or breastfeeding women continued cannabis use during the study period. The data identified found suggested a heterogeneous picture regarding cannabis users' compliance with the LRCUG's recommendations. Non-compliance is highest for recommendations regarding modes-of-use, and applies to minorities of users for other risks factors. These sub-groups are at elevated risk for acute (e.g., accidents) or long-term (e.g., dependence) cannabis-related harms contributing to the public health burden. Appropriate targeted interventions in these areas require improvement.

Treatment Implications Associated with Cannabis and Tobacco Co-Use

PURPOSE OF THE REVIEW

The goal of this article is to summarize the treatment-focused literature on cannabis and tobacco co-use and the treatment implications of co-use. This review will focus on: 1) the impact of co-use on cessation outcomes, 2) compensatory use/substitution of the non-treated substance among co-users, and 3) treatment interventions to address co-use. This article will highlight the limitations to co-use captured in the literature and offer considerations and directives for co-use research and treatment moving forward.

RECENT FINDINGS

The degree to which co-use affects cessation for a single, targeted substance remains in question, as the literature is largely mixed. Cannabis treatment trials are better equipped to answer these questions given that they do not typically exclude tobacco users. While the relationship between tobacco use and poorer cannabis outcomes appears to have some evidence, the reverse relationship (cannabis use affecting tobacco outcomes) is not consistently supported.

SUMMARY

The co-use of cannabis and tobacco and its impact on single substance cessation and/or compensatory substance use during cessation is generally overlooked in treatment trials, while interventions to address both substances are rare. Capturing co-use adds burden for researchers, clinicians, and participants, but is warranted given the prevalence of co-use and a rapidly changing cannabis and tobacco regulatory environment, which may further complicate co-occurring substance use. Co-users are a heterogeneous population; trials focused on co-users, in addition to better data capture and consistent terminology, will aid in an understanding of nuanced patterns of co-use critical to inform treatment interventions.

Legal cannabis market shares during Canada's first year of recreational legalisation

BACKGROUND

This study estimated legal products' share of Canada's total cannabis consumption during the first year of recreational legalisation, October 2018 to September 2019.

METHODS

Government data was used to estimate monthly recreational sales in dollars per capita, grams per user, and percentage share of kilograms or litres consumed. As explanatory factors, the analysis considered provincial differences in retail pricing (percentage mark-ups) and store density (stores per million users), as well as national monthly production of dry cannabis (kilograms) and cannabis oil (litres) finished products.

RESULTS

Legal recreational products' share of Canada's overall cannabis consumption began at 7.8% in October 2018 and grew to 23.7% by September 2019, with an average of 14.5% over the first 12 months. Sales growth was delayed by shortages of both dry cannabis products and licensed stores, but not cannabis oils. Across the 10 provinces, legal recreational shares in September 2019 varied from 13% to 70%; differences in store densities and retail prices partly explained the variation. Prince Edward Island's large 70% share seemed due to it having minimal product shortages, high store densities, and low prices.

CONCLUSIONS

Legal recreational products captured market share to the extent they were available, accessible, and low-priced. Problems with those factors slowed the initial expansion of legal product sales but also suggested ways to gradually increase their market share.

Cannabis and work: Need for more research

Cannabis sativa is one of the oldest and most widely used plants in the world with a variety of industrial, medical, and nonmedical applications. Despite its long history, cannabis-derived products remain a source of controversy across the fields of medicine, law, and occupational safety and health. More favorable public attitudes about cannabis in the US have resulted in greater access to cannabis through legalization by states, leading to more consumption by workers. As more states adopt cannabis access laws, and as more workers choose to consume cannabis products, the implications for existing workplace policies, programs, and practices become more salient. Past workplace practices were grounded in a time when cannabis consumption was always viewed as problematic, considered a moral failing, and was universally illegal. Shifting cultural views and the changing legal status of cannabis indicate a need for research into the implications and challenges relating to cannabis and work. This commentary suggests research needs in the following areas: (a) data about industries and occupations where cannabis consumption among workers is most prevalent; (b) adverse health consequences of cannabis consumption among workers; (c) workplace supported recovery programs; (d) hazards to workers in the emerging cannabis industry; (e) relationship between cannabis consumption and occupational injuries; (f) ways to assess performance deficits and impairment from cannabis consumption; (g) consumption of synthetic cannabinoids to evade detection by drug testing; (h) cannabis consumption and its effect on occupational driving; and (i) ways to craft workplace policies and practices that take into consideration conflicting state and federal laws pertaining to cannabis.

Cannabis use and the risk of anxiety and depression in women: A comparison of three Swedish cohorts

BACKGROUND

The associations between cannabis use and anxiety or depression remain unclear. If cannabis affects these conditions, it is of interest to examine possible changes in cannabis use over time, in relation to anxiety and depression, as cannabis potency has increased in recent decades.

METHODS

Cohorts from the Women and Alcohol in Gothenburg study (n = 1 100), from three time periods were used to examine associations over time between cannabis use and anxiety and depression. Logistic regression analyses were used and relative excess risk due to interaction (RERI) was calculated to examine potential additive interactions between period of cannabis use, cannabis use, and anxiety or depression.

FINDINGS

Cannabis use was associated with anxiety in the oldest cohort (examined 1986-1992, born 1955/65), OR = 5.14 (1.67-15.80, 95 % CI), and with both anxiety and depression in the youngest cohort (examined 2000-2015, born 1980/93), OR = 1.66 (1.00-2.74, 95 % CI) and 2.37 (1.45-3.86, 95 % CI), respectively. RERI was significant between cannabis use and depression in the youngest cohort when compared with older cohorts (1.68 (0.45-2.92, 95 % CI)).

LIMITATIONS

Cross-sectional data prevent statements on causality, though between-cohort comparisons are possible.

CONCLUSION

The association between cannabis use and depression becomes more pronounced when adding the effect of period of use rather than looking at the effect of cannabis use itself. This study provides clinicians and public health workers with scientifically underpinned knowledge regarding the link between cannabis use and depression, of particular importance given increasing cannabis potency.

A within-person comparison of the subjective effects of higher vs. lower-potency cannabis

BACKGROUND

Cannabis concentrates have much higher concentrations of THC than marijuana (flower) and are quickly gaining popularity in the United States. One hypothesis is that use of higher-THC cannabis (concentrates) might result in greater intoxication and more severe acute negative effects than lower-THC cannabis (marijuana), but few studies have compared the subjective effects of concentrates and marijuana.

METHODS

Current (past-year) cannabis users were recruited online to complete a survey about their cannabis use. Cannabis users who reported using both marijuana and concentrates (n = 574) answered questions about the subjective effects of marijuana and, subsequently, the subjective effects of concentrates. Subjective effects were obtained for the following domains: affect, cognitive function, psychotic-like experiences, physiological effects, and reduced consciousness.

RESULTS

Participants reported using marijuana between 5-6 times per week and concentrates slightly more than once per month. Within-person comparisons of the subjective effects of marijuana and concentrates showed that marijuana was rated as producing greater overall positive effects (Marijuana: M = 5.6, Concentrates: M = 4.5; Cohen's d = 0.75, paired t(561) = 14.67, p < .001), including greater positive affect and enhanced cognitive function. Negative effects of both marijuana and concentrates were minimal. Marijuana was selected over concentrates as the 'preferred type' of cannabis by 77.5 % of participants.

CONCLUSIONS

The main difference in the subjective effects of marijuana and concentrates is in terms of their positive effects, with marijuana producing greater positive effects than concentrates. Negative effects of marijuana and concentrates were small, suggesting that extreme negative effects are unlikely for regular cannabis users.

Characterising heterogeneity in the use of different cannabis products: latent class analysis with 55 000 people who use cannabis and associations with severity of cannabis dependence

BACKGROUND

As new cannabis products and administration methods proliferate, patterns of use are becoming increasingly heterogeneous. However, few studies have explored different profiles of cannabis use and their association with problematic use.

METHODS

Latent class analysis (LCA) was used to identify subgroups of past-year cannabis users endorsing distinct patterns of use from a large international sample (n = 55 240). Past-12-months use of six different cannabis types (sinsemilla, herbal, hashish, concentrates, kief, edibles) were used as latent class indicators. Participants also reported the frequency and amount of cannabis used, whether they had ever received a mental health disorder diagnosis and their cannabis dependence severity via the Severity of Dependence Scale (SDS).

RESULTS

LCA identified seven distinct classes of cannabis use, characterised by high probabilities of using: sinsemilla & herbal (30.3% of the sample); sinsemilla, herbal & hashish (20.4%); herbal (18.4%); hashish & herbal (18.8%); all types (5.7%); edibles & herbal (4.6%) and concentrates & sinsemilla (1.7%). Relative to the herbal class, classes characterised by sinsemilla and/or hashish use had increased dependence severity. By contrast, the classes characterised by concentrates use did not show strong associations with cannabis dependence but reported greater rates of ever receiving a mental health disorder diagnosis.

CONCLUSIONS

The identification of these distinct classes underscores heterogeneity among cannabis use behaviours and provides novel insight into their different associations with addiction and mental health.

Cannabis knowledge and implications for health: Considerations regarding the legalization of non-medical cannabis

Cannabis contains over a hundred of different cannabinoids, of which Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most well studied. The use of high-potency cannabis, containing high concentrations of THC and low concentrations of CBD, has been linked to adverse health outcomes, particularly for adolescents and young adults. Recently, an increase in cannabis potency has been observed in jurisdictions that legalized the sale of cannabis for non-medical purposes. Moreover, an increase of cannabis use and cannabis-related emergency treatment have also been observed in these jurisdictions. At the same time, risk perception regarding cannabis use has decreased in these populations. Trivializing language and an increased appearance of commercial cannabis in the public space may lead to a generalized underestimation of the risks of cannabis use. New regulation models principally focus on the creation of a legal cannabis market economy, the diversion of profits from illegal markets, and the reduction of costs associated with prohibition. However, an approach that specifically focuses on the rights to the health and safety of the individual should be considered in order to reduce the risks associated with cannabis legalization. Such an approach should promote and protect individual and social health and safety, establish a strict quality control of legal cannabis products regulated according to THC and CBD content, and eliminate all sorts of incentives to use, thus providing a more consistent, sustainable, and ethical framework for the legalization of non-medical cannabis use.

The association between recreational cannabis commercialization and cannabis exposures reported to the US National Poison Data System

BACKGROUND AND AIMS

Recreational cannabis has been legalized in 11 states and District of Columbia (DC) in the United States. Among these, 10 states further permitted retail sale to provide a legal supply to adults. This study examined the associations of cannabis exposures with recreational cannabis legalization and commercialization.

DESIGN

Secondary data analysis of state-quarter level cannabis exposures during 2010-17 in the United States. Linear regressions with a difference-in-differences design were used to compare pre- and post-legalization trends in states that legalized recreational cannabis to contemporaneous trends in states that did not legalize recreational cannabis.

SETTING

United States, including all 50 states and DC.

CASES

Cannabis exposures reported to the US National Poison Data System.

MEASUREMENTS

The primary outcome was state age-adjusted cannabis exposures reported to the US National Poison Data System per 1 000 000 population per quarter. The two policy variables of interest included (1) the enactment of recreational cannabis legalization (i.e. removing penalties for adults' possession of cannabis in a small amount for recreational use) and (2) the initiation of recreational cannabis commercialization (i.e. providing a legal supply of cannabis to adults through licensed dispensaries).

FINDINGS

The association between a state's enactment of recreational cannabis legalization and its changes in cannabis exposures was statistically non-significant overall. After controlling for recreational cannabis legalization, however, the initiation of recreational cannabis commercialization was associated with 5.06-5.80 more exposures per 1 000 000 population per quarter (67-77% increase relative to the pre-legalization average), depending on the composition of comparison states. The increase associated with commercialization was higher among minors than adults (7.97-9.53 versus 3.83-4.21 more exposures), higher among males than females (6.16-7.56 versus 3.76-3.91 more exposures) and higher among exposures with medical consequences than those without medical consequences (4.09-4.79 versus 0.97-1.01 more exposures).

CONCLUSION

An increase in cannabis exposures reported to the US National Poison Data System was observed following recreational cannabis commercialization in the United States.

Cannabis Exposure During Critical Windows of Development: Epigenetic and Molecular Pathways Implicated in Neuropsychiatric Disease

PURPOSE OF REVIEW

Cannabis exposure during critical windows of development may have intergenerational physiological consequences disrupting epigenetic programming and marks. This review examines the literature relating to pre-gestational and prenatal cannabinoid exposure and its effect on genes and molecular pathways related to the development of psychiatric disease.

RECENT FINDINGS

Developmental cannabis exposure alters epigenetic processes with functional gene consequences. These include potentially heritable alterations in genes and molecular pathways critical for brain development and associated with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), schizophrenia, addiction, and other psychiatric diseases. Cannabis consumption and mental health illness in adolescents and young adults are increasing in the United States (U.S.), and recent studies suggest that cannabis consumption during critical periods of brain development could contribute to mental health illness through epigenetic mechanisms. These findings warrant future studies and consideration by regulators and health communicators.

Retrospective cross-sectional analysis of the changes in marijuana use in the USA, 2005-2018

OBJECTIVES

Understanding trends of marijuana use in the USA throughout a period of particularly high adoption of marijuana-legalisation, and understanding demographics most at risk of use, is important in evolving healthcare policy and intervention. This study analyses the demographic-specific changes in the prevalence of marijuana use in the USA between 2005 and 2018.

DESIGN, SETTING AND PARTICIPANTS

A 14-year retrospective cross-sectional analysis of the National Health and Nutrition Examination Survey database, a publicly available biennially collected national survey, weighted to represent the entire US population. A total of 35 212 adults between 18 and 69 years old participated in the seven-cycles of surveys analysed (2005-2018).

PRIMARY OUTCOME MEASURED

Lifetime use, first use before 18 years old, and past-year use of marijuana.

RESULTS

The majority of adults reported ever using marijuana. While the overall prevalence of lifetime marijuana use remained stable (p=0.53), past-year use increased significantly between 2005 and 2018 (p<0.001) with highest rate of past-year use among younger age groups (p<0.001), males (p<0.001) and those with income below poverty level (p<0.001). Past-year use was the most common among non-Hispanic blacks, and less common among Hispanic/Mexican populations (p<0.002). Trends in past-year use increased among all age categories, males/females, all ethnicities, those with high school education/above, and those at all income levels (p<0.01 for all).

CONCLUSIONS

While lifetime marijuana use remained stable, past-year use significantly increased between 2005 and 2018. While past-year use remained the most common in younger age groups, males, non-Hispanic blacks and those with lower income; increasing trends in past-year use were significant for all age, sex, race and income categories, and for those with high school education/above. With high adoption of marijuana-legalisation laws during this period, our results suggest an associated increase in past-year marijuana use.An accurate understanding of those most at risk can help to inform decisions of healthcare policy-makers and professionals, and facilitate a safe transition of changing marijuana legalisation and use in the USA.

Relationship among subjective responses, flavor, and chemical composition across more than 800 commercial cannabis varieties

BACKGROUND

Widespread commercialization of cannabis has led to the introduction of brand names based on users' subjective experience of psychological effects and flavors, but this process has occurred in the absence of agreed standards. The objective of this work was to leverage information extracted from large databases to evaluate the consistency and validity of these subjective reports, and to determine their correlation with the reported cultivars and with estimates of their chemical composition (delta-9-THC, CBD, terpenes).

METHODS

We analyzed a large publicly available dataset extracted from Leafly.com where users freely reported their experiences with cannabis cultivars, including different subjective effects and flavour associations. This analysis was complemented with information on the chemical composition of a subset of the cultivars extracted from Psilabs.org . The structure of this dataset was investigated using network analysis applied to the pairwise similarities between reported subjective effects and/or chemical compositions. Random forest classifiers were used to evaluate whether reports of flavours and subjective effects could identify the labelled species cultivar. We applied Natural Language Processing (NLP) tools to free narratives written by the users to validate the subjective effect and flavour tags. Finally, we explored the relationship between terpenoid content, cannabinoid composition and subjective reports in a subset of the cultivars.

RESULTS

Machine learning classifiers distinguished between species tags given by "Cannabis sativa" and "Cannabis indica" based on the reported flavours:  = 0.828 ± 0.002 (p < 0.001); and effects:  = 0.9965 ± 0.0002 (p < 0.001). A significant relationship between terpene and cannabinoid content was suggested by positive correlations between subjective effect and flavour tags (p < 0.05, False-Discovery-rate (FDR)-corrected); these correlations clustered the reported effects into three groups that represented unpleasant, stimulant and soothing effects. The use of predefined tags was validated by applying latent semantic analysis tools to unstructured written reviews, also providing breed-specific topics consistent with their purported subjective effects. Terpene profiles matched the perceptual characterizations made by the users, particularly for the terpene-flavours graph (Q = 0.324).

CONCLUSIONS

Our work represents the first data-driven synthesis of self-reported and chemical information in a large number of cannabis cultivars. Since terpene content is robustly inherited and less influenced by environmental factors, flavour perception could represent a reliable marker to indirectly characterize the psychoactive effects of cannabis. Our novel methodology helps meet demands for reliable cultivar characterization in the context of an ever-growing market for medicinal and recreational cannabis.

Facing the option for the legalisation of cannabis use and supply in New Zealand: An overview of relevant evidence, concepts and considerations

ISSUES

Non-medical cannabis policies are changing, including towards legalisation-with-regulation frameworks. New Zealand will hold a public referendum on cannabis legalisation in 2020. We reviewed data on cannabis use and health/social harms; policy reform options; experiences with and outcomes of reforms elsewhere; and other relevant considerations towards informing policy choices in the upcoming referendum.

APPROACH

Relevant epidemiological, health, social, criminal justice and policy studies and data were identified and comprehensively reviewed.

KEY FINDINGS

Cannabis use is common (including in New Zealand) and associated with risks for health and social harms, mainly concentrated in young users; key harms are attributable to criminalisation. 'Decriminalisation' reforms have produced ambivalent results. Existing cannabis legalisation frameworks vary considerably in main parameters. Legalisation offers some distinct advantages, for example regulated use, products and user education, yet outcomes depend on essential regulation parameters, including commercialisation, and policy ecologies. While major changes in use are not observed, legalisation experiences are inconclusive to date, including mixed health and social outcomes, with select harms increasing and resilient illegal markets. It is unclear whether legalisation reduces cannabis exposure or social harms (e.g. from enforcement) for youth.

IMPLICATIONS/CONCLUSIONS

No conclusive overall evidence on the outcomes of legalisation elsewhere exists, nor is evidence easily transferable to other settings. Legalisation offers direct social justice benefits for adults, yet overall public health impacts are uncertain. Legalisation may not categorically improve health or social outcomes for youth. Legalisation remains a well-intended, while experimental policy option towards more measured and sensible cannabis control and overall greater policy coherence, requiring close monitoring and possible adjustments depending on setting-specific outcomes.

THC and CBD blood and brain concentrations following daily administration to adolescent primates

BACKGROUND

Cannabis availability with high concentrations of Δ-9-tetrahydrocannabinol (THC) and a range of THC to cannabidiol (CBD) ratios has increased in parallel with a rise in daily cannabis consumption by adolescents. Unanswered questions in adolescents include: 1) whether THC blood concentrations and THC metabolites remain stable or change with prolonged daily dosing, 2) whether CBD modulates THC pharmacokinetic properties and alters THC accumulation in brain, 3) whether blood THC levels reflect brain concentrations.

METHODS

In adolescent squirrel monkeys (Saimiri boliviensis), we determined whether a four-month regimen of daily THC (1 mg/kg) or CBD (3 mg/kg) + THC (1 mg/kg) administration (IM) affects THC, THC metabolites, and CBD concentrations in blood or brain.

RESULTS

Blood THC concentrations, THC metabolites and CBD remained stable during chronic treatment. 24 h after the final THC or CBD + THC injection, blood THC and CBD concentrations remained relatively high (THC: 6.0-11 ng/mL; CBD: 9.7-19 ng/mL). THC concentrations in cerebellum and occipital cortex were approximately twice those in blood 24 h after the last dose and did not significantly differ in subjects given THC or CBD + THC.

CONCLUSIONS

In adolescent monkeys, blood levels of THC, its metabolites or CBD remain stable after daily dosing for four months. Our model suggests that any pharmacological interactions between CBD and THC are unlikely to result from CBD modulation of THC pharmacokinetics. Finally, detection of relatively high brain THC concentrations 24 h after the final dose of THC suggests that the prolonged actions of THC may contribute to persistent cognitive and psychomotor disruption after THC- or cannabis-induced euphoria wane.

Perceived Importance of Factors in Cannabis Purchase Decisions: A Best-worst Scaling Experiment

BACKGROUND

Consumers' access to cannabis has been considerably expanded in US states where recreational cannabis was legalized and commercialized. However, little is known about the important factors influencing consumers' purchase decisions in cannabis retail dispensaries. This study examined cannabis users' perceptions of the relative importance of policy-relevant factors when they made cannabis purchase decisions.

METHODS

An online survey was administered to 817 adult cannabis users in seven states in the US (California, Colorado, Maine, Massachusetts, Nevada, Oregon, and Washington) that had approved cannabis commercialization by the time of interview in January 2018. Twenty policy-relevant cannabis attributes were evaluated, including those pertaining to product characteristics, quality, package characteristics, price and free sample, store characteristics, and restrictions on use. A best-worst scaling experiment was employed, which asked respondents to select the most and the least important attributes in a choice scenario. Each respondent answered 10 choice scenarios, each including a random combination of four attributes out of the 20. The relative importance of each attribute was evaluated using hierarchical Bayesian estimation of mixed logit models.

RESULTS

Overall, 'quality', 'strain type', 'price', 'THC' (tetrahydrocannabinol) and 'pesticide' were the top five important attributes affecting cannabis users' willingness to buy cannabis in a dispensary. These five attributes jointly accounted for approximately half of the total importance. In subsample analysis, both recreational and dual-purpose users attached higher importance to 'quality', 'THC', and 'price', whereas medical users tended to think 'CBD' (cannabidiol) and 'pesticide' were more important. All cannabis users perceived 'package' to be the least important attribute. Gender had no major differences in perceptions.

CONCLUSIONS

Cannabis users in general perceived product characteristics, quality, and price to be important factors in their willingness to buy cannabis in dispensaries. There were heterogeneities in the perceptions by cannabis use purposes. The findings might deserve consideration in cannabis policy design.

Assessment of Incorporation of Lessons From Tobacco Control in City and County Laws Regulating Legal Marijuana in California

IMPORTANCE

As marijuana continues to be legalized in many states, little is known about best regulatory practice, exposing the population to significant potential harm.

OBJECTIVE

To assess the extent to which potential best practices, including those from tobacco control, were incorporated into state and local marijuana policies in California.

DESIGN AND SETTING

California legalized medical marijuana in 1996 and adult recreational use in 2016, effective in January 2018. A cross-sectional study with data collection and analysis from February 1 to November 30, 2019, measured the adoption of potential demand reduction and youth protection best practices, including restrictions on sales, products, marketing, warnings, and taxation. Laws in effect by January 31, 2019, were verified and all 539 California local jurisdictions were studied.

MAIN OUTCOMES AND MEASURES

Adoption of potential best practices in marijuana laws for demand reduction and youth protection.

RESULTS

The laws of 534 of California's 539 jurisdictions (99%) were successfully identified; 263 of these 534 jurisdictions (49%) allowed any retail sale of marijuana, covering 57% of the state's population. More than one-third of jurisdictions allow sales of marijuana for adult recreational use (203 of 534 [38%]); of those, 122 allow storefront dispensaries and 81 allow sales by delivery only. A total of 257 of 534 jurisdictions (48%) allow medical sales. Of 147 jurisdictions allowing medical or adult use dispensaries, 93 (63%) limited the number of licenses, with a mean of 1 store for every 19 058 residents (range, 154-355 143). The state imposed no limits on number of dispensaries or deliverers. Forty-two jurisdictions increased the state-specified distances required between dispensaries and schools. Only 8 jurisdictions allowing retail sales imposed restrictions on products exceeding state regulations; 1 prohibited sale of flavored products, 3 prohibited sale of marijuana-infused beverages, and 5 imposed additional restrictions on edible marijuana products. No jurisdictions limited potency of products sold, although 1 established a potency-linked tax. The state did not limit or tax potency, except for establishing a standard 10-mg dose of tetrahydrocannabinol for edible marijuana products, nor did they limit manufacturing or sale of flavored products. The state required only a health warning in 6-point font on packages. Twenty-seven jurisdictions required additional health warnings in stores or on packages, 27 allowed onsite consumption of marijuana products, and 13 allowed marijuana-related events. More than half of jurisdictions legalizing any cannabis commerce (154 of 289 [53%]) did not tax marijuana locally and little revenue was captured for prevention. Much of the state excise and cultivation taxes is slated for youth substance use prevention and treatment.

CONCLUSIONS AND RELEVANCE

In implementing legalization of marijuana in California, local policies varied widely. Where marijuana was legalized, many lessons from tobacco control to reduce demand, limit harm, and prevent youth use were not adopted, potentially creating greater risk of harm.

Assessing the public health impacts of legalizing recreational cannabis use: the US experience

The sale of cannabis for adult recreational use has been made legal in nine US states since 2012, and nationally in Uruguay in 2013 and Canada in 2018. We review US research on the effects of legalization on cannabis use among adults and adolescents and on cannabis-related harms; the impact of legalizing adult recreational use on cannabis price, availability, potency and use; and regulatory policies that may increase or limit adverse effects of legalization. The legalization of recreational cannabis use in the US has substantially reduced the price of cannabis, increased its potency, and made cannabis more available to adult users. It appears to have increased the frequency of cannabis use among adults, but not so far among youth. It has also increased emergency department attendances and hospitalizations for some cannabis-related harms. The relatively modest effects on cannabis use to date probably reflect restrictions on the number and locations of retail cannabis outlets and the constraints on commercialization under a continued federal prohibition of cannabis. Future evaluations of legalization should monitor: cannabis sales volumes, prices and content of tetrahydrocannabinol; prevalence and frequency of cannabis use among adolescents and adults in household and high school surveys; car crash fatalities and injuries involving drivers who are cannabis-impaired; emergency department presentations related to cannabis; the demand for treatment of cannabis use disorders; and the prevalence of regular cannabis use among vulnerable young people in mental health services, schools and the criminal justice system. Governments that propose to legalize and regulate cannabis use need to fund research to monitor the impacts of these policy changes on public health, and take advantage of this research to develop ways of regulating can-nabis use that minimize adverse effects on public health.

Practical Considerations of Hypotheses and Evidence in Cannabis Pharmacotherapy: Refining Expectations of Clinical Endocannabinoid Deficiency

An Industry founded on the promotion of presumed health and wellness benefits of cannabis use continues to grow in the United States, despite the lack of substantial evidence in support of the many claims being made. Several hypotheses exist regarding the role of endocannabinoids in human health and the pertinence of phytocannabinoids as pharmacotherapies for addressing their dysregulation. An opinion is offered regarding the tenuous nature of these assumptions and questions are raised regarding how best to interpret the complex metabolic interplay of the still vaguely defined endocannabinoid system.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Short- and Long-Term Effects of Cannabis on Headache and Migraine

Use of cannabis to alleviate headache and migraine is relatively common, yet research on its effectiveness remains sparse. We sought to determine whether inhalation of cannabis decreases headache and migraine ratings as well as whether gender, type of cannabis (concentrate vs flower), delta-9-tetrahydrocannabinol, cannabidiol, or dose contribute to changes in these ratings. Finally, we explored evidence for tolerance to these effects. Archival data were obtained from Strainprint, a medical cannabis app that allows patients to track symptoms before and after using different strains and doses of cannabis. Latent change score models and multilevel models were used to analyze data from 12,293 sessions where cannabis was used to treat headache and 7,441 sessions where cannabis was used to treat migraine. There were significant reductions in headache and migraine ratings after cannabis use. Men reported larger reductions in headache than women and use of concentrates was associated with larger reductions in headache than flower. Further, there was evidence of tolerance to these effects. PERSPECTIVE: Inhaled cannabis reduces self-reported headache and migraine severity by approximately 50%. However, its effectiveness appears to diminish across time and patients appear to use larger doses across time, suggesting tolerance to these effects may develop with continued use.

Pine rosin identified as a toxic cannabis extract adulterant

Pine rosin (colophony) has been identified as a potentially new adulterant in cannabis oil. Its inhalation toxicity poses a significant health concern to users. For example, pine rosin fumes are released during soldering, and have been cited as a causative agent of occupational asthma. Symptoms also include desquamation of bronchial epithelium, which has also been observed in e-cigarette or vaping product used-associated lung injury (EVALI) patients. The sample analyzed herein was acquired from a cannabis industry source, also contains medium chain triglycerides and oleamide, the latter of which is a hypnotic that is commonly found in the synthetic marijuana product Spice, or K2. A combination of proton nuclear magnetic resonance (¹H NMR) and high pressure liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESIMS) was used to unambiguously identify major pine rosin ingredients such as abietic and other resin acids. Comparison to commercial samples of pure pine rosin confirmed the assignment.

Intensity of cannabis use: Findings from three online surveys

BACKGROUND

Drug use is often measured in terms of prevalence, meaning the number of people who used any amount in the last month or year, but measuring the quantity consumed is critical for making informed regulatory decisions and estimating the effects of policy changes. Quantity is the product of frequency (e.g., number of use days in the last month) and intensity (amount consumed per use day). Presently, there is imperfect understanding of the extent to which more frequent users also consume more intensively.

METHODS AND DATA

We examine cannabis flower consumption reported in three similar online surveys fielded in times and places where cannabis was and was not legal. These convenience samples returned enough valid responses (n = 2,618) to examine consumption across different frequencies of use via analyses of measures of central tendency, data visualizations, and multivariate regressions. Additional calculations incorporate data from the National Survey on Drug Use and Health.

FINDINGS

Respondents who reported using daily (i.e., 30 days in the past month) consumed almost twice as much per day of use on average as did those reporting less than daily. We find only modest increases in intensity among those using less than daily, but then a substantial increase (p< 0.001) for those who use daily. Most respondents report that on heavy or light use days their consumption differs from a typical day of use by a factor of 2 or more, but only about 25% of days were described as heavy or light. We estimate those using cannabis 21+ days a month account for 80% of consumption vs. 71% of the days of use.

DISCUSSION

Daily cannabis users consume more intensively than others, including near-daily users. When possible, survey questions should move beyond the presence or absence of use and number of days used.

Cannabis and the Developing Adolescent Brain

Purpose of Review

This review summarizes (1) recent trends in delta-9-tetrahydrocannabionol [THC] and cannabidiol (CBD) content in cannabis products, (2) neurobiological correlates of cannabis use on the developing adolescent brain, (3) effects of cannabis on psychiatric symptoms and daily functioning in youth (i.e., academic performance, cognition, sleep and driving), (4) cannabis products used to relieve or treat medical issues in youth, and (5) available treatments for cannabis use disorder in adolescence.

Recent findings

Despite marked increases in THC content and availability of cannabis, there has been a decline in perceived risk and an increase in use of THC extract products among youth in the United States. The primary psychiatric symptoms associated with cannabis use in youth are increased risk for addiction, depressive, and psychotic symptoms. Cannabis alters endocannabinoid system function which plays a central role in modulating the neurodevelopment of reward and stress systems. To date, few studies have examined neurobiological mechanisms underlying the psychiatric sequalae of cannabis exposure in youth. Adolescent cannabis exposure results in impaired cognition, sleep, and driving ability. There are very limited FDA-approved cannabinoid medications, none of them supporting their use for the treatment of psychiatric symptoms. Behavioral therapies are currently the mainstay of treating cannabis misuse, with no pharmacotherapies currently approved by the FDA for cannabis use disorder in youth.

Summary

Here, we summarize the most up-to-date knowledge on the neurobiological psychiatric, and daily function effects of the most commonly used cannabinoids, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). We then review FDA approved medical use of cannabinoid treatments as well as pharmacological and psychological treatments for cannabis use disorder in youth. Our current understanding of the effects of cannabis on the developing brain and treatments for cannabis misuse in youth remain limited. Future research aimed at examining the neurobiological effects of cannabis, with objective measures of exposure, over the course of pediatric development and in relation to psychiatric symptoms are needed.

Availability, retail price and potency of legal and illegal cannabis in Canada after recreational cannabis legalisation

INTRODUCTION AND AIMS

There is little objective market data on the price or potency of legal and illegal cannabis products following recreational cannabis legalisation.

DESIGN AND METHODS

In the 2 months post-legalisation in Canada (November-December 2018), legal and illegal cannabis retailers were identified from government lists and online directories. The store location, price and Δ9-tetrahydrocannabinol (THC) and cannabidiol levels of dried herb and cannabis cookies were collected from retailer websites or Weedmaps.

RESULTS

We identified 185 legal retailers (22 online stores, 163 storefronts; 65 government-run stores, 120 private stores) and 944 illegal retailers (791 delivery-only services, 157 storefronts). Relative to legal dried herb, illegal dried herb was lower in price (1 g: $10.23 vs. $11.08, ⅛ oz: $9.37/g vs. $10.88/g, ½ oz: $8.18/g vs. $8.85/g; P < 0.05 for all) and higher in potency (THC: 20.5% vs. 16.1%, cannabidiol: 2.4% vs. 1.7%; P < 0.05 for both). Legal private stores had higher prices for dried herb than government-run stores (1 g: $13.08 vs. $10.89, ⅛ oz: $12.75/g vs. $10.45/g, ½ oz: $10.85/g vs. $8.71/g, 1 oz: $8.54/g vs. $7.22/g; P < 0.05 for all). On average, one cannabis cookie in the illegal market contained 96 mg of THC and cost $1.57 per 10 mg of THC.

DISCUSSION AND CONCLUSIONS

In the 2 months post-legalisation, illegal cannabis was less expensive, with higher labelled THC content than legal cannabis, although the scope of these differences was more modest than estimates from other crowdsourced and self-reported data. Direct monitoring of cannabis price and potency from legal and illegal retailers is needed to examine the impact of legalisation over time.

Mapping cannabis potency in medical and recreational programs in the United States

Cannabis related online searches are associated with positive attitudes toward medical cannabis, particularly when information is obtained from dispensaries. Since pain is the main reason for medicinal cannabis use, information from dispensary websites has the potential to shape the attitude of pain patients towards cannabis. This is relevant because cannabis has demonstrated efficacy in neuropathic pain with low tetrahydrocannabinol (THC) concentrations (< 5-10%), in contrast to potent cannabis (>15% THC), which is highly rewarded in the recreational realm. The role of CBD in pain is not clear, however it has gained popularity. Thus, we hypothesize that the potency of medical cannabis that is advertised online is similar to the cannabis advertised for recreational purposes, which would potentially create a misconception towards medical cannabis. The current lack of knowledge surrounding advertised potencies in the legal cannabis market limits the ability to generate clear policies regarding online advertising to protect patients that are willing to use cannabis for their condition. Thus, we evaluated the advertised THC and CBD content of cannabis products offered online in dispensaries in the United States to determine products' suitability to medicinal use and compare the strength of products offered in legal medical and recreational programs. We recorded THC and CBD concentrations for all herb cannabis products provided by dispensary websites and compared them between or within states. Four Western states (CA, CO, NM, WA) and five Northeastern states (ME, MA, NH, RI, VT) were included. A total of 8,505 cannabis products across 653 dispensaries were sampled. Despite the clear differences between medicinal and recreational uses of cannabis, the average THC concentration advertised online in medicinal programs was similar (19.2% ±6.2) to recreational programs (21.5% ±6.0) when compared between states with different programs, or between medicinal and recreational programs within the same states (CO or WA). Lower CBD concentrations accompanied higher THC products. The majority of products, regardless of medicinal or recreational programs, were advertised to have >15% THC (70.3% - 91.4% of products). These stated concentrations seem unsuitable for medicinal purposes, particularly for patients with chronic neuropathic pain. Therefore, this information could induce the misconception that high potency cannabis is safe to treat pain. This data is consistent with reports in which THC and CBD in products from legal dispensaries or in nationwide products from the illegal market were actually measured, which indicates that patients consuming these products may be at risk of acute intoxication or long-term side effects. Our study offers grounds to develop policies that help prevent misconceptions toward cannabis and reduce risks in pain patients.

Marijuana Use in Pregnancy: A Review

Importance

Marijuana is the most commonly used dependent substance in pregnancy. The main active chemical of marijuana (delta-9-tetrahydrocannabinol [THC]) readily crosses the placenta, and cannabinoid receptors have been identified in fetal brain and placenta. As a result, prenatal marijuana use could potentially have detrimental impact on fetal development.

Objective

This review aims to summarize the existing literature and current recommendations for marijuana use while pregnant or lactating.

Evidence Acquisition

A PubMed literature search using the following terms was performed to gather relevant data: "cannabis," "cannabinoids," "marijuana," "fetal outcomes," "perinatal outcomes," "pregnancy," "lactation."

Results

Available studies on marijuana exposure in pregnancy were reviewed and support some degree of developmental disruption, including an increased risk of fetal growth restriction and adverse neurodevelopmental consequences. However, much of the existing prenatal marijuana research was performed in the 1980s, when quantities of THC were lower and the frequency of use was less. Additionally, most human studies are also limited and conflicting as most studies have been observational or retrospective, relying primarily on patient self-report and confounded by polysubstance abuse and small sample sizes, precluding determination of a causal effect specific for marijuana. Given the paucity of evidence, it is currently recommended to avoid using marijuana while pregnant or when breastfeeding.

Conclusion and Relevance

There is a critical need for research on effects in pregnancy using present-day THC doses. Once the adverse perinatal effects of marijuana exposure are identified and well characterized, patient education and antenatal surveillance can be developed to predict and mitigate its impact on maternal and fetal health.

"You have to make some money before you can do some good": Balancing the commercial, social and public health objectives in a "community enterprise" regulatory model for alcohol and cannabis

INTRODUCTION

New Zealand's alcohol licensing trusts are social enterprises that operate retail alcohol outlets in their districts and distribute profits back to the community. There have been calls for a similar "social enterprise" approach to legal cannabis sales. However, social enterprises face unique challenges in balancing commercial and social objectives.

AIM

To explore mechanisms that support the balancing of commercial, social and public health objectives in alcohol trusts and identify learnings for cannabis reform.

METHOD

Thematic analysis of interviews with 16 internal and external key informants (trust board members, trust retail managers, community activists, law enforcement) from two alcohol trust districts.

RESULTS

Key informants overwhelmingly conceptualised alcohol trusts as business entities, but commercial success was also seen as a means to help the community. Interviewees' perceptions of trusts' social mission ranged from simple "corporate social responsibility" to a "genuine" community orientation. Despite a near-monopolistic market position, forces within and outside the trusts create pressures to conform to standard commercial behaviour, including strategic placement of alcohol outlets. Participants attributed the potential public health benefits of the trusts to reduced density of alcohol retail outlets and ease of enforcement. The pragmatic political goal of maintaining a favourable public image (to secure survival of the trust and re-election of individual trustees) was the key mechanism balancing commercial and social objectives. Ethical dilemmas related to the sale of alcohol and conflicts of interest in allocating community funds were evident. Discord was "negotiated" with the community via the public discussion and voting, providing opportunity to correct mission drift.

CONCLUSIONS

The need to maintain a positive public image (to ensure favourable electoral results) was a key mechanism helping to balance the commercial and social goals of alcohol trusts. A community trust model for retail cannabis sales could similarly provide constraints on commercial behaviour while funding community services.

Out-of-state cannabis purchases in the United States

BACKGROUND

Cannabis legalization at the US state level may have implications for cross-border purchases and diversion of legal products. The current study examined the association between out-of-state purchases and 1) cannabis regulations; and 2) the length of time a state has had recreational retail sales.

METHODS

Data come from US respondents who participated in Wave 1 of the International Cannabis Policy Study (ICPS), conducted in August-October 2018. Respondents were aged 16-65 years who had used cannabis in the past 12 months (n = 4320). Respondents were recruited using the Nielsen Consumer Insights Global Panel. Binary logistic regression models examined likelihood of any out-of-state cannabis purchases in the prior year, including differences by cannabis regulations, and time since recreational cannabis retail sales began.

RESULTS

Overall, 15.0 % of US cannabis users had made any out-of-state cannabis purchases in the past 12 months. Respondents in states where recreational cannabis was legal were less likely to make any out-of-state purchases than respondents in states where only medical cannabis was legal (AOR = 0.45, 95 % CI: 0.34-0.60, p < 0.001) and where all cannabis was prohibited (AOR = 0.36, 95 % CI: 0.26-0.50, p < 0.001). Among respondents in 'legal' states, a longer history of legal sales was associated with a lower likelihood of out-of-state cannabis purchases (AOR = 0.82, 95 % CI: 0.72-0.93, p = 0.002).

CONCLUSION

The findings demonstrate that consumers in states where recreational cannabis is legal were less likely to purchase cannabis out-of-state than consumers in states where recreational cannabis is not legal. Future research should examine which states people travel to purchase cannabis and why.