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

Consensus paper of the WFSBP task force on cannabis, cannabinoids and psychosis

OBJECTIVES

The liberalisation of cannabis laws, the increasing availability and potency of cannabis has renewed concern about the risk of psychosis with cannabis.

METHODS

The objective of the WFSBP task force was to review the literature about this relationship.

RESULTS

Converging lines of evidence suggest that exposure to cannabis increases the risk for psychoses ranging from transient psychotic states to chronic recurrent psychosis. The greater the dose, and the earlier the age of exposure, the greater the risk. For some psychosis outcomes, the evidence supports some of the criteria of causality. However, alternate explanations including reverse causality and confounders cannot be conclusively excluded. Furthermore, cannabis is neither necessary nor sufficient to cause psychosis. More likely it is one of the multiple causal components. In those with established psychosis, cannabis has a negative impact on the course and expression of the illness. Emerging evidence also suggests alterations in the endocannabinoid system in psychotic disorders.

CONCLUSIONS

Given that exposure to cannabis and cannabinoids is modifiable, delaying or eliminating exposure to cannabis or cannabinoids, could potentially impact the rates of psychosis related to cannabis, especially in those who are at high risk for developing the disorder.

Cannabinoid Poisoning-Related Emergency Department Visits and Inpatient Hospitalizations in Kentucky, 2017 to 2019

Background and objectives: Cannabis is the most used federally illicit substance. Due to widespread medicinal use and state-level legalization, public perceptions of cannabis have shifted toward the assumption that cannabis is safe. However, cannabinoids can cause adverse medical complications that may lead people to seek treatment. This study characterized cannabinoid poisoning-related medical encounters, poisoning involving cannabinoids and other psychoactive substances, and cannabinoid poisoning-related cardiac complications. Methods: Administrative billing data for emergency department visits and inpatient hospitalizations in acute care facilities with a discharge date from January 1, 2017 to December 31, 2019 were used to characterize cannabinoid poisoning events in Kentucky, identified by ICD-10-CM diagnosis code T40.7X. Results: There were 1,490 encounters of cannabinoid poisoning; patients were primarily non-Hispanic White males, ages 15-44, who had Medicaid and lived in a metropolitan area. Of those, 31.21% involved poisoning with a second psychoactive substance, primarily stimulants and/or opioids, and 17.72% experienced a cardiac complication. Cannabinoid-polydrug poisoning was associated with inpatient treatment (χ2=199.18, p < 0.001) and cardiac complications (χ2=4.58, p < 0.001). Discussion and Conclusions: These results are consistent with other state-level data. Patients who were diagnosed with cannabis-polydrug poisoning, compared to cannabis alone poisoning, had greater odds of hospital admission and cardiac complications, and longer length of hospital stays. Scientific Significance: The health risks of cannabinoid use must be more broadly recognized, while timely and accurate data need to be shared to guide policies on cannabis access. Future research on cannabinoid poisoning should consider the involvement of other psychoactive drugs.

Perceptions About Cannabis Following Legalization Among Pregnant Individuals With Prenatal Cannabis Use in California

IMPORTANCE

As rates of prenatal cannabis use increase and cannabis legalization spreads across the US, studies are needed to understand the potential impacts of legalization from the perspectives of pregnant individuals who use cannabis.

OBJECTIVE

To characterize pregnant individuals' perspectives on legalization of cannabis for adult use in California (effective in 2018) in relation to prenatal cannabis use behaviors and beliefs.

DESIGN, SETTING, AND PARTICIPANTS

This qualitative study was conducted in Kaiser Permanente Northern California, a large health care system with universal screening for self-reported cannabis use at entrance to prenatal care. Eighteen semistructured focus groups were conducted from November 17 to December 17, 2021, using a secure video conferencing platform with Black and White pregnant participants who self-reported cannabis use during early pregnancy. Data were analyzed from March to June 2022.

MAIN OUTCOMES AND MEASURES

Video-recorded interviews were transcribed and analyzed using thematic analysis to identify major themes and subthemes.

RESULTS

Among 53 participants (mean [SD] age, 30.3 [5.2] years), 23 (43%) identified as non-Hispanic Black and 30 (57%) identified as non-Hispanic White; 16 participants (30%) reported continued cannabis use at the time of recruitment. Major themes regarding the perceived impact of legalization included easier access (via retailers and delivery), greater acceptance (including reduced stigma and more discussions about prenatal cannabis use with health care practitioners), and trust in cannabis retailers (including safety and effectiveness of diverse products sold and perceptions of cannabis retailer employees as knowledgeable, nonjudgmental, and caring). Responses were mixed about whether retailer marketing and advertising were associated with prenatal cannabis use and whether legalization resulted in reduced concerns about Child Protective Services involvement.

CONCLUSION AND RELEVANCE

The findings of this qualitative study suggest pregnant individuals perceive cannabis legalization as having reduced barriers to prenatal cannabis use and that legalization has created challenges and opportunities for supporting the health of pregnant individuals. The results of this qualitative study highlight key areas that can be further explored in future educational materials, public health campaigns, and policy adaptations to address increasing rates of prenatal cannabis use.

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.

Hours high as a proxy for marijuana use quantity in intensive longitudinal designs

BACKGROUND

Measuring marijuana use quantity in survey research is complicated due to wide variation in the types (e.g., flower, edibles) and potency of marijuana products and in the modes (e.g., smoking, dabbing) used to consume products. There is currently no gold standard marijuana use quantity measure for survey research. This study examined whether number of hours high can be used as a proxy for marijuana use quantity in survey research, particularly in intensive longitudinal designs.

METHODS

Participants came from a community sample of young adults participating in a longitudinal study on simultaneous alcohol and marijuana use that used a longitudinal measurement-burst design in which participants completed surveys on up to 14 consecutive days in up to five bursts across nearly two calendar years. Those who reported using marijuana on at least one sampled day were included in present analyses (N = 379; Mage = 21.6; 50.7 % female). Hypotheses were tested using Poisson multilevel models and a logistic regression.

RESULTS

Within persons, mode-specific marijuana use quantity variables predicted same-day number of hours high indicating evidence of initial criterion validity. In turn, hours high predicted same-day negative marijuana-related consequences indicating evidence of proximal predictive validity. Between persons, participants' average number of hours high was positively associated with their odds of possible cannabis use disorder following the last burst demonstrating distal predictive validity.

CONCLUSIONS

Number of hours high may be a parsimonious proxy for measuring marijuana use quantity (regardless of mode of use) in survey research, particularly in intensive longitudinal designs.

Association of cannabis potency with mental ill health and addiction: a systematic review

Cannabis potency, defined as the concentration of Δ⁹-tetrahydrocannabinol (THC), has increased internationally, which could increase the risk of adverse health outcomes for cannabis users. We present, to our knowledge, the first systematic review of the association of cannabis potency with mental health and addiction (PROSPERO, CRD42021226447). We searched Embase, PsycINFO, and MEDLINE (from database inception to Jan 14, 2021). Included studies were observational studies of human participants comparing the association of high-potency cannabis (products with a higher concentration of THC) and low-potency cannabis (products with a lower concentration of THC), as defined by the studies included, with depression, anxiety, psychosis, or cannabis use disorder (CUD). Of 4171 articles screened, 20 met the eligibility criteria: eight studies focused on psychosis, eight on anxiety, seven on depression, and six on CUD. Overall, use of higher potency cannabis, relative to lower potency cannabis, was associated with an increased risk of psychosis and CUD. Evidence varied for depression and anxiety. The association of cannabis potency with CUD and psychosis highlights its relevance in health-care settings, and for public health guidelines and policies on cannabis sales. Standardisation of exposure measures and longitudinal designs are needed to strengthen the evidence of this association.

Machine Learning-Based Quantification of (-)-trans-Δ-Tetrahydrocannabinol from Human Saliva Samples on a Smartphone-Based Paper Microfluidic Platform

(-)-trans-Δ-Tetrahydrocannabinol (THC) is a major psychoactive component in cannabis. Despite the recent trends of THC legalization for medical or recreational use in some areas, many THC-driven impairments have been verified. Therefore, convenient, sensitive, quantitative detection of THC is highly needed to improve its regulation and legalization. We demonstrated a biosensor platform to detect and quantify THC with a paper microfluidic chip and a handheld smartphone-based fluorescence microscope. Microfluidic competitive immunoassay was applied with anti-THC-conjugated fluorescent nanoparticles. The smartphone-based fluorescence microscope counted the fluorescent nanoparticles in the test zone, achieving a 1 pg/mL limit of detection from human saliva samples. Specificity experiments were conducted with cannabidiol (CBD) and various mixtures of THC and CBD. No cross-reactivity to CBD was found. Machine learning techniques were also used to quantify the THC concentrations from multiple saliva samples. Multidimensional data were collected by diluting the saliva samples with saline at four different dilutions. A training database was established to estimate the THC concentration from multiple saliva samples, eliminating the sample-to-sample variations. The classification algorithms included k-nearest neighbor (k-NN), decision tree, and support vector machine (SVM), and the SVM showed the best accuracy of 88% in estimating six different THC concentrations. Additional validation experiments were conducted using independent validation sample sets, successfully identifying positive samples at 100% accuracy and quantifying the THC concentration at 80% accuracy. The platform provided a quick, low-cost, sensitive, and quantitative point-of-care saliva test for cannabis.

Characteristics of the Washington cannabis market from 2014 to 2016

BACKGROUND

The state of Washington legalized cannabis for adult use in 2012 and retail stores began to open in 2014. While details of the legal market have been tracked by the state, the total market for cannabis and characteristics of purchasers can only be identified through surveys.

METHODS

Six cross-sectional samples of the Privatization of Spirits in Washington (PSW) surveys were collected between January 2014 and October 2016 with two in each year. Random digit dial procedures were used to recruit a sample aged 18 and older, with 40% of cases from mobile phones. A total of 5492 respondents participated. Analyses of the population-weighted sample utilized purchasing amounts and frequencies, use frequency and related measures to estimate total and mean amounts and expenditures. Sensitivity analyses were conducted for key assumptions.

RESULTS

The market for cannabis flower is estimated to have increased from 158 metric tons and $1.23 billion in 2014 to 222 metric tons and $1.7 billion in 2016, with little change from 2014 to 2015. Purchases from legal sources, retail and dispensaries, were estimated at 69% of the total market. Daily or near daily (DND) users accounted for about 83% of sales in 2014, rising to 91% in 2016. The prevalence of past year use rose substantially from 25% in 2014 to 32% in 2016, with DND use rising from 10.2 to 11.3%. Average purchase amounts for DND users rose from 291 g in 2014 to 374 g in 2016, while mean amounts among non-DND users declined from 78 to 28.6 g.

CONCLUSIONS

The expansion of retail cannabis stores in Washington appears to have led to increased market size in 2016 with all of the increase attributed to DND users. Frequent users may be important to consider in legalization evaluations.

Clinical management of cannabis withdrawal

BACKGROUND AND AIMS

Cannabis withdrawal is a well-characterized phenomenon that occurs in approximately half of regular and dependent cannabis users after abrupt cessation or significant reductions in cannabis products that contain Δ⁹ -tetrahydrocannabinol (THC). This review describes the diagnosis, prevalence, course and management of cannabis withdrawal and highlights opportunities for future clinical research.

METHODS

Narrative review of literature.

RESULTS

Symptom onset typically occurs 24-48 hours after cessation and most symptoms generally peak at days 2-6, with some symptoms lasting up to 3 weeks or more in heavy cannabis users. The most common features of cannabis withdrawal are anxiety, irritability, anger or aggression, disturbed sleep/dreaming, depressed mood and loss of appetite. Less common physical symptoms include chills, headaches, physical tension, sweating and stomach pain. Despite limited empirical evidence, supportive counselling and psychoeducation are the first-line approaches in the management of cannabis withdrawal. There are no medications currently approved specifically for medically assisted withdrawal (MAW). Medications have been used to manage short-term symptoms (e.g. anxiety, sleep, nausea). A number of promising pharmacological agents have been examined in controlled trials, but these have been underpowered and positive findings not reliably replicated. Some (e.g. cannabis agonists) are used 'off-label' in clinical practice. Inpatient admission for MAW may be clinically indicated for patients who have significant comorbid mental health disorders and polysubstance use to avoid severe complications.

CONCLUSIONS

The clinical significance of cannabis withdrawal is that its symptoms may precipitate relapse to cannabis use. Complicated withdrawal may occur in people with concurrent mental health and polysubstance use.

Evidence on the acute and residual neurocognitive effects of cannabis use in adolescents and adults: a systematic meta-review of meta-analyses

BACKGROUND

Cannabis is among the most consumed psychoactive substances world-wide. Considering changing policy trends regarding the substance, it is crucial to understand more clearly its potential acute and residual adverse effects from a public health viewpoint. Cognitive function is one of the targeted areas with conflicting findings. This meta-review measured the magnitude of acute and residual effects of cannabis on cognition in adolescents and adults provided by meta-analyses and evaluated quality of evidence.

METHODS

A systematic search was performed in PubMed, PsycINFO, Web of Science and Google Scholar. Meta-analyses were included if they quantitatively examined the performances of users from the general population on cognitive tasks.

RESULTS

The search retrieved 10 eligible meta-analyses (71 effects sizes, n = 43 761) with evidence ranging from low to moderate quality, which were categorized into domains of cognitive functions: executive functions (k = 7), learning and memory (k = 5), attention (k = 4), processing speed (k = 5), perceptual motor function (k = 2) and language (k = 2). Verbal learning and memory displayed the most robust evidence and were most impaired by acute cannabis intoxication that persisted after intoxication passed. Small-to-moderate acute and residual   adverse effects were reported for executive functioning. Cannabis use led to small deficits in inhibitory processes and flexibility, whereas small-to-moderate deficits were reported for working memory and decision-making. Evidence regarding processing speed and attention has shown that cannabis administration induced small-to-moderate adverse effects and residual neurocognitive deficits were observed in heavy cannabis-using youths. Results showed no significant difference between cannabis users and non-users on language, and small-to-moderate effects for simple motor skills.

CONCLUSION

Meta-analytical data on the acute effects of cannabis use on neurocognitive function have shown that cannabis intoxication leads to small to moderate deficits in several cognitive domains. These acute impairments accord with documented residual effects, suggesting that the detrimental effects of cannabis persist beyond acute intake.

Cannabis significantly alters DNA methylation of the human ovarian follicle in a concentration-dependent manner

Cannabis is increasingly consumed by women of childbearing age, and the reproductive and epigenetic effects are unknown. The purpose of this study was to evaluate the potential epigenetic implications of cannabis use on the female ovarian follicle. Whole-genome methylation was assessed in granulosa cells from 14 matched case-control patients. Exposure status was determined by liquid chromatography-mass spectrometry (LC-MS/MS) measurements of five cannabis-derived phytocannabinoids in follicular fluid. DNA methylation was measured using the Illumina TruSeq Methyl Capture EPIC kit. Differential methylation, pathway analysis and correlation analysis were performed. We identified 3679 differentially methylated sites, with two-thirds affecting coding genes. A hotspot region on chromosome 9 was associated with two genomic features, a zinc-finger protein (ZFP37) and a long non-coding RNA (FAM225B). There were 2214 differentially methylated genomic features, 19 of which have been previously implicated in cannabis-related epigenetic modifications in other organ systems. Pathway analysis revealed enrichment in G protein-coupled receptor signaling, cellular transport, immune response and proliferation. Applying strict criteria, we identified 71 differentially methylated regions, none of which were previously annotated in this context. Finally, correlation analysis revealed 16 unique genomic features affected by cannabis use in a concentration-dependent manner. Of these, the histone methyltransferases SMYD3 and ZFP37 were hypomethylated, possibly implicating histone modifications as well. Herein, we provide the first DNA methylation profile of human granulosa cells exposed to cannabis. With cannabis increasingly legalized worldwide, further investigation into the heritability and functional consequences of these effects is critical for clinical consultation and for legalization guidelines.

Association of Tetrahydrocannabinol Content and Price in Herbal Cannabis Products Offered by Dispensaries in California: A Purview of Consumers/Patients

Background and Aims

The U.S. legal cannabis market is saturated with products containing high levels of tetrahydrocannabinol (THC), with no distinction between medical and recreational programs. This omnipresence of potent cannabis products seems to be driven by the recreational realm, where cannabis with the highest THC content is prized. This prevalence of highly potent cannabis is conveyed to medical programs, which places consumers (patients) at higher risk for over consumption and cannabis use disorder. Thus, understanding what factors influence the market that patients face in medical cannabis programs could shed light on the risks of legal cannabis. The supply and demand dynamic of the US for-profit cannabis market could explain the current market composition; therefore, we postulate that a financial gain could influence the perpetuation of the prevalence of high THC products in legal cannabis dispensaries. We investigate whether THC content in popular cannabis products correlates with higher prices and assess whether some attributes (type of product, chemovars, or presence of cannabidiol (CBD) affect the association of THC with price.

Methods

We focus on the world's largest cannabis market, California. We randomly selected dispensaries across the state, screened for a web presence and product menu, determined the most prevalent product type, and collected THC and CBD concentration, price, and other product attributes.

Results

We observed that herbal products were more common, they had THC concentrations greater than 10%, and THC concentrations positively correlated with price. This correlation existed in flower and preroll presentations, all chemovar, and independently of the level of CBD. CBD did not correlate with price; however, the presence of CBD diminished the THC and price correlation particularly in products with high THC (&gt;15%).

Conclusions

Overall, highly potent herbal cannabis products (&gt;15% THC) are the majority of products offered and more expensive regardless of product type or chemovar in California dispensaries, suggesting that a financial gain contributes to the current market composition. Efforts to limit the availability of highly potent THC products and educate consumers about potential harms are needed.

Potency and Therapeutic THC and CBD Ratios: U.S. Cannabis Markets Overshoot

Background and aims: The effects exuded by cannabis are a result of the cannabinoids trans-Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD), and is dependent upon their pharmacological interaction and linked to the two cannabinoids’ concentrations and ratios. Based on current literature and trends of increasing cannabis potency, we postulate that most medical cannabis products with THC and CBD have ratios capable of producing significant acute intoxication and are similar to recreational products. We will test this by organizing products into clinically distinct categories according to TCH:CBD ratios, evaluating the data in terms of therapeutic potential, and comparing the data obtained from medical and recreational programs and from states with differing market policies.

Methods: We utilized data encompassing online herbal dispensary product offerings from nine U.S. states. The products were analyzed after being divided into four clinically significant THC:CBD ratio categories identified based on the literature: CBD can enhance THC effects (THC:CBD ratios ≥1:1), CBD has no significant effect on THC effects (ratios ∼ 1:2), CBD can either have no effect or can mitigate THC effects (ratios 1:>2 < 6), or CBD is protective against THC effects (ratios ≤1:6).

Results: A significant number of products (58.5%) did not contain any information on CBD content. Across all states sampled, the majority (72–100%) of both medical and recreational products with CBD (>0%) fall into the most intoxicating ratio category (≥1:1 THC:CBD), with CBD likely enhancing THC’s acute effects. The least intoxicating categories (1:>2 < 6 and ≤1:6 THC:CBD) provided the smallest number of products. Similarly, the majority of products without CBD (0%) contained highly potent amounts of THC (>15%). These results were consistent, regardless of differing market policies in place.

Conclusions: Despite the distinct goals of medical and recreational cannabis users, medical and recreational program product offerings are nearly identical. Patients seeking therapeutic benefits from herbal cannabis products are therefore at a substantial risk of unwanted side effects, regardless of whether they obtain products from medical or recreational programs. Efforts are needed to better inform patients of the risks associated with high potency cannabis and the interaction between THC and CBD, and to help shape policies that promote more therapeutic options.

The International Cannabis Toolkit (iCannToolkit): a multidisciplinary expert consensus on minimum standards for measuring cannabis use

BACKGROUND

The lack of an agreed international minimum approach to measuring cannabis use hinders the integration of multidisciplinary evidence on the psychosocial, neurocognitive, clinical and public health consequences of cannabis use.

METHODS

A group of 25 international expert cannabis researchers convened to discuss a multidisciplinary framework for minimum standards to measure cannabis use globally in diverse settings.

RESULTS

The expert-based consensus agreed upon a three-layered hierarchical framework. Each layer-universal measures, detailed self-report and biological measures-reflected different research priorities and minimum standards, costs and ease of implementation. Additional work is needed to develop valid and precise assessments.

CONCLUSIONS

Consistent use of the proposed framework across research, public health, clinical practice and medical settings would facilitate harmonisation of international evidence on cannabis consumption, related harms and approaches to their mitigation.

A Systematic Review and Narrative Synthesis of the Evolution of Adolescent and Young Adult Cannabis Consumption Before and After Legalization

PURPOSE

To systematically review evidence assessing the evolution of cannabis consumption before and after the implementation of non-medical cannabis legislation.

METHODS

MEDLINE, PubMED, PsycINFO, Scopus, and Web of Science were systematically searched for studies that examined change in cannabis consumption before and after nonmedical cannabis legislation. Data were tabulated by study design, levels of consumption, and individual subgroups. Data were analyzed using a narrative synthesis approach, considering study quality.

RESULTS

32 studies were included (11 higher quality and 21 lower quality). 40% of higher quality evidence supported an increase in postlegalization consumption (55% did not report a change and 5% reported a decrease). The increase was most evident for young adults (42% of higher quality evidence) and in the consumption in the past month (37% of higher quality evidence). There was limited supporting evidence for new users having grown in response to legalization. Based on subgroup analysis, the increase in postlegalization consumption was higher among women and those who engage in binge-drinking.

CONCLUSIONS

Higher quality evidence suggests an increase in adolescent past-month consumption of cannabis following legalization in several geographical jurisdictions. Consumption evolution prelegalization and postlegalization differed by age group and for young women and for binge drinkers. Consumption evolution differences suggest a variety of strategies might be required in efforts to lower public health impacts of cannabis consumption following legalization.

Medical conditions of primary care patients with documented cannabis use and cannabis use disorder in electronic health records: a case control study from an academic health system in a medical marijuana state

BACKGROUND

Approximately 3.8% of adults worldwide have used cannabis in the past year. Understanding how cannabis use is associated with other health conditions is crucial for healthcare providers seeking to understand the needs of their patients, and for health policymakers. This paper analyzes the relationship between documented cannabis use disorders (CUD), cannabis use (CU) and other health diagnoses among primary care patients during a time when medical use of marijuana was permitted by state law in California, United States of America.

METHODS

The study utilized primary care electronic health record (EHR) data from an academic health system, using a case-control design to compare diagnoses among individuals with CUD/CU to those of matched controls, and those of individuals with CUD diagnoses with individuals who had CU otherwise documented. Associations of documented CU and CUD with general medical conditions and health conditions associated with cannabis use (both medical and behavioral) were analyzed using conditional logistic regression.

RESULTS

Of 1,047,463 patients with ambulatory encounters from 2013-2017, 729 (0.06%) had CUD diagnoses and 3,731 (0.36%) had CU documented in their EHR. Patients with documented CUD and CU patients had significantly (p < 0.01) higher odds of most medical and behavioral diagnoses analyzed. Compared to matched controls, CUD-documented patients had highest odds of other substance use disorders (OR = 21.44: 95% CI 9.43-48.73), any mental health disorder (OR = 6.99; 95% CI 5.03-9.70) social anxiety disorder (OR = 13.03; 95% CI 2.18-77.94), HIV/AIDS (OR = 7.88: 95% CI 2.58-24.08), post-traumatic stress disorder (OR = 7.74: 95% CI 2.66-22.51); depression (OR = 7.01: 95% CI 4,79-10.27), and bipolar disorder (OR = 6.49: 95% CI 2.90-14.52). Compared to matched controls, CU-documented patients had highest odds of other substance use disorders (OR = 3.64; 95% CI 2.53-5.25) and post-traumatic stress disorder (OR = 3.41; 95% CI 2.53-5.25). CUD-documented patients were significantly more likely than CU-documented patients to have HIV/AIDS (OR = 6.70; 95% CI 2.10-21.39), other substance use disorder (OR = 5.88; 95% CI 2.42-14.22), depression (OR = 2.85; 95% CI 1.90-4.26), and anxiety (OR = 2.19: 95% CI 1.57-3.05) diagnoses.

CONCLUSION

The prevalence of CUD and CU notation in EHR data from an academic health system was low, highlighting the need for improved screening in primary care. CUD and CU documentation were associated with increased risk for many health conditions, with the most elevated risk for behavioral health disorders and HIV/AIDS (among CUD-documented, but not CU-documented patients). Given the strong associations of CUD and CU documentation with health problems, it is important for healthcare providers to be prepared to identify CU and CUD, discuss the pros and cons of cannabis use with patients thoughtfully and empathically, and address cannabis-related comorbidities among these patients.

Impact of cannabis legalization on healthcare utilization for psychosis and schizophrenia in Colorado

BACKGROUND

Emergency department (ED) visits involving psychosis and schizophrenia have increased at a rate exceeding population growth in the United States over the past decade. Research shows a strong dose-response relationship between chronic use of high-potency cannabis and odds of developing symptoms of psychosis. The aim of this study was to evaluate the impact of cannabis legalization on psychosis and schizophrenia-related ED visits in Colorado.

METHODS

Using administrative data from Colorado Hospital Association (CHA) on county-level quarterly ED visits between January 1, 2013, and December 31, 2018, we applied a difference-in-difference analysis to examine how new exposure to recreational cannabis dispensaries after 2014 differentially influenced the rate of ED visits for psychosis and schizophrenia, comparing counties with no prior medical cannabis dispensary exposure to counties with low or high medical dispensary exposure.

RESULTS

As recreational dispensaries per 10,000 residents increased, there was no significant association with the rate of schizophrenia ED visits per capita (incidence rate ratio or IRR: 0.95, 95% CI [0.69, 1.30]) while the rate of psychosis visits increased 24% (IRR: 1.24, 95% CI [1.02, 1.49]). Counties with no previous medical dispensaries experienced larger increases in schizophrenia ED visits than counties already exposed to a low level of medical dispensaries, but this effect was not significant. Counties with low baseline medical exposure had lower increases in rates of psychosis visits than counties with high baseline medical exposure (IRR 0.83, 95% CI [0.69, 0.99]).

CONCLUSIONS

There was a positive association between the number of cannabis dispensaries and rates of psychosis ED visits across all counties in Colorado. Although it is unclear whether it is access to products, or the types of products that may be driving this association, our findings suggest there is a potential impact on the mental health of the local population that is observed after cannabis legalization.

Young adults' familiarity with different cannabis product terms: the need for standardized cannabis surveys

Background

Cannabis legalization has resulted in the proliferation of cannabis products. Participants’ familiarity with terms for these products may have implications for assessment, as unfamiliarity with particular terms may result in under-reports of use.

Methods

A convenience sample of 861 college students from one U.S. university completed a survey in the spring of 2020 about their familiarity with a variety of cannabis product terms and use of a variety of cannabis products.

Results

Participants varied in their familiarity with cannabis product terms. For example, with regard to terms for cannabis concentrates with very high concentrations of THC, 85% of participants reported being familiar with the term “wax pen or THC oil,” but only 27% reported being familiar with the term “butane hash oil (BHO)” (i.e., the oil that composes most concentrates). Moreover, of participants who reported use of concentrates based on selecting pictures of the products they had used (n = 324, 40%), 99% (n = 322) reported having seen a “wax pen or THC oil” based on a written list of product terms, whereas only 20% (n = 65) reported having seen “butane hash oil (BHO).” This suggests that asking about use of “butane hash oil” use may result in lower rates of cannabis concentrate use than asking about use of “wax pen/THC oil.” With regard to terms for marijuana flower, 29% of participants (n = 248) reported being unfamiliar with the term marijuana “buds or flowers.” Of participants who reported use of marijuana flower based on selecting pictures of the products they had used (38% of the sample, n = 329), only 86% (n = 282) reported having seen marijuana “buds or flowers” based on a written list of product terms. This suggests that asking about use of marijuana “buds or flowers” use could result in under-reporting due to lack of familiarity with that term. Finally, when asked to select pictures of the cannabis product(s) that participants thought constituted “marijuana,” participants most commonly selected pictures of marijuana flower (93%), followed by wax pen/THC oil (57%) and edibles (49%).

Conclusions

Young adults vary in their familiarity with cannabis product terms, and some may under-report cannabis use in surveys that rely on written cannabis product terms. Young adults also differ in terms of which cannabis products they think constitute “marijuana.” Although participants’ familiarity with specific cannabis product terms in this sample may not generalize to other populations, results highlight the need for standardized surveys of cannabis use that incorporate pictures of cannabis products to overcome issues related to variability in familiarity with cannabis product terms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00125-0.

Cannabis Use Among Young Adults in Washington State After Legalization of Nonmedical Cannabis

Objectives. To examine changes in prevalence of cannabis use and of cannabis use disorder symptomatology among young adults from 2014 to 2019 in Washington State, where nonmedical (or "recreational") cannabis was legalized in 2012 and retail stores opened in July 2014. Methods. We used 6 years of cross-sectional data collected annually from 2014 (premarket opening) to 2019 from 12 963 (∼2000 per year) young adults aged 18 to 25 years residing in Washington. Logistic regression models estimated yearly change in prevalence of cannabis use at different margins and related outcomes. Results. Prevalence of past-year, at least monthly, at least weekly, and daily use of cannabis increased for young adults, although increases were driven by changes among those aged 21 to 25 years. There was also a statistically significant increase in prevalence of endorsing at least 2 of 5 possible symptoms associated with cannabis use disorder. Conclusions. Among young adults in Washington, particularly those of legal age, prevalences of cannabis use and cannabis use disorder symptomatology have increased since legalization. This trend may require continued monitoring as the nonmedical cannabis market continues to evolve. (Am J Public Health. 2022;112(4):638-645. https://doi.org/10.2105/AJPH.2021.306641).

Estimating Usual Grams per Day of Marijuana Use from Purchases

BACKGROUND

Quantifying average amounts of marijuana used per day or per occasion of use helps inform understanding population-level patterns of use and use-related harm, but better estimates and estimation methods are needed. Users have difficulty in reporting use amounts, but purchase amounts may be more clearly recalled.

METHODS

Measures of individual's use and purchasing frequency and details of purchases such as the amounts and products bought and the cost of these were collected in six cross-sectional representative surveys of the population 18 and older in the state of Washington from 2014 to 2016. Analyses utilize purchase information on both flower and other marijuana products to estimate mean amounts per use day and predict use amounts for non-purchasers.

RESULTS

Mean marijuana use per use day among purchasers was 1.35 grams and non-purchasers estimated mean use amount per day was 0.71 grams. Lower mean use per day was a found for women and the most frequent users. Based on these estimates, total past year marijuana use for purchasers had a mean of 184.8 grams and the mean for non-purchasers was 28 grams.

CONCLUSIONS

Methods based on purchasing details can be used to estimate individual's marijuana quantity per occasion and total use amount per year, providing additional outcome measures for analyses of predictors of individual marijuana consumption and facilitating more detailed analyses of risks for marijuana harms.

Trends and characteristics of cannabis-associated emergency department visits in the United States, 2006-2018

BACKGROUND

Cannabis policies are rapidly changing in the United States, yet little is known about how this has affected cannabis-associated emergency department (ED) visits.

METHODS

We studied trends in cannabis-associated ED visits and identified differences by visit characteristics. Cannabis-associated ED visits from 2006 to 2018 were identified from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project's (HCUP) Nationwide Emergency Department Sample (NEDS). JoinPoint analysis was used to identify trends from 2006 to 2014, prior to medical coding changes in 2015, and Z-tests were used to compare annual rate changes from 2016 to 2018. Changes in rates from 2017 to 2018 were examined by visit characteristics.

RESULTS

From 2006-2014, the rate of cannabis-associated ED visits increased, on average, 12.1% annually (p < 0.05), from 12.3 to 34.7 visits per 100,000 population. The rate increased 17.3% from 2016 to 2017 (p < 0.05) and 11.1% from 2017 to 2018 (p < 0.05). From 2017-2018, rates of visits increased for both males (8.7%; p < 0.05) and females (15.9%; p < 0.05). Patients 0-14 years and 25 years and older had significant rate increases from 2017 to 2018 as did the Midwest region (36.8%; p < 0.05), the Northeast (9.2%; p < 0.05), and the South (4.5%; p < 0.05).

CONCLUSIONS

Cannabis-associated ED visits are on the rise and subgroups are at increased risk. Some potential explanations for increases in cannabis-associated ED visits include increased availability of cannabis products, increased use, and diversity of products available in marketplaces. Strategies are needed to prevent youth initiation, limit potentially harmful use among adults, and ensure safe storage where cannabis use is legal.

Cannabis Use Disorder: A Behavioral Economic Perspective

Purpose of Review

To explore relations between behavioral economic demand for cannabis and cannabis use disorder (CUD). Prior reviews have focused on drug demand in relation to use outcomes more generally. Complementing and enhancing prior work synthesizing research on cannabis demand, the present review endeavors to determine whether specific demand indices derived from the marijuana purchase task are most reliably related to CUD. Additionally, sociodemographic characteristics of participants in these studies were reviewed to identify whether certain populations were underrepresented in behavioral economic cannabis research.

Recent Findings

Behavioral economic demand is related to CUD; intensity and elasticity of cannabis demand were consistently associated with CUD diagnosis and severity. However, frequently, only select demand indices were assessed or reported, precluding the ability to confirm which indices are superior for denoting CUD risk. Further, most studies enrolled samples that were predominately young adults, Caucasian, and male.

Summary

As CUD becomes more prevalent in the wake of cannabis legalization, identification of robust predictors of CUD risk is paramount. Cannabis demand is consistently associated with CUD; however, individual indices of import in this relationship remain ambiguous. Subsequent research is needed to confirm index-specific markers of disordered cannabis use, and whether links between demand and CUD generalize across diverse populations.

A social media intervention for cannabis use among emerging adults: Randomized controlled trial

PURPOSE

Cannabis use is increasing among emerging adults (ages 18-25), necessitating the need for prevention interventions. Using a novel platform - social media - we developed an 8-week motivational interviewing and cognitive-behavioral intervention targeting cannabis use among emerging adults. Herein, we report on the feasibility and acceptability of the intervention in a pilot trial.

PROCEDURES

For NCT04187989 we recruited N = 149 emerging adults who used cannabis (at least 3 times/week for the past month) using social media advertising. Their mean age was 21.0 years (SD = 2.2); 55.7% were female. Most were White (70.5%; 20.1% Black/African American, 9.4% Other races), with 20.1% identifying as Hispanic/Latinx. Participants were randomized to the 8-week intervention or an 8-week attention-placebo control condition, both delivered in secret Facebook groups by electronic health coaches (e-coaches). Follow-up assessments occurred at 3- and 6-months.

RESULTS

The intervention was well-received and follow-up rates were high; fidelity was good. Intervention participants rated e-coaches significantly higher in terms of helpfulness, warmth, etc., compared to control participants. Intervention participants were more likely to engage with and recommend the group. In terms of percentage reductions in cannabis outcomes, the intervention group evidenced absolute reductions over time in several measures of cannabis consumption across modalities. In an adjusted model, reductions in vaping days in the intervention group, relative to attention-control, reached statistical significance (p = .020, D =.40).

CONCLUSIONS

This social media intervention for emerging adults' cannabis use was feasible and acceptable in the target population warranting future testing in a fully powered trial.

Cannabis flower prices and transitions to legal sources after legalization in Canada, 2019-2020

BACKGROUND

The post-tax price of legal cannabis has the potential to influence whether consumers transition from the illegal to legal cannabis market. The aims of the study were to: 1) estimate the percentage who report purchasing dried flower at different sources; 2) estimate the unit price of dried flower; and 3) examine the association between price and legality of purchase source.

METHODS

Repeat cross-sectional survey data come from Canadian respondents from the International Cannabis Policy Study conducted in 2019 and 2020. Respondents were recruited through online commercial panels, of legal age to purchase cannabis (up to 65 years), and purchased dried flower in the past 12-months (n = 4923). Weighted binary logistic regression models examined the association between price and legality of source.

RESULTS

The proportion of consumers last purchasing dried flower from legal sources increased from 2019 to 2020 (45.7% vs 58.1%) and in the past 12-months, the average percent of dried flower consumers reported purchasing from legal sources increased from 2019 to 2020 (55.7% vs 67.5%). The mean price of legal dried flower decreased in 2020 ($12.63 vs $11.16; p < 0.001), but remained more expensive than illegal dried flower in both years ($12.63 vs $9.04 in 2019; p < 0.001, $11.16 vs $9.41 in 2020; p < 0.001).

CONCLUSIONS

Two years after legalization in Canada, the price of dried flower from legal sources decreased, along with a greater percentage of consumers purchasing from legal sources than after one year. Price and retail policies must continue to encourage the transition to the legal market in Canada.

Characteristics that influence purchase choice for cannabis products: a systematic review

Introduction

When non-medical cannabis use became legal, government regulators implemented policies to encourage safer consumption through access to a regulated market. While this market is growing, sales still occur through unregulated channels. This systematic review identifies factors influencing cannabis purchasing to help policymakers understand why consumers still purchase illicit market cannabis (registered with PROSPERO CRD42020176079).

Methods

A comprehensive search strategy included databases in health, business, and social science fields (inception to June 2020). Studies were eligible for inclusion if they were conducted with persons who purchase cannabis and examine at least one attribute that would influence purchase choice and were published in the English language. Studies could be of any methodological design. Two independent reviewers completed two levels of screening, and all extraction was verified by a second reviewer. A qualitative synthesis of the findings was completed. The quality of the included studies was assessed using the Mixed Methods Appraisal Tool.

Results

Of the 4839 citations screened, 96 were eligible for full-text review and 35 were included in the final synthesis. Aspects of price were the most common factors (27 studies). Twenty studies measured price elasticity; most studies found that demand was price inelastic. Many other attributes were identified (e.g., product quality, route of administration, product recommendations, packaging), but none were explored in depth. Eleven studies addressed aspects of product quality including demand elasticity based on quality, potency, and aroma. Studies also explored consumer-perceived “quality” but provided no definition; differences in quality appeared to impact consumer choice. Smoking cannabis appeared to be the preferred route of administration but was only examined in three studies. There was insufficient data to understand in the impact of other attributes on choice. There appeared to be preference heterogeneity for different attributes based on the consumer’s experience, reason for use, and gender.

Conclusion

While price influences choices, demand is relatively inelastic. This suggests that consumers may be seeking lowest-cost, unregulated cannabis to avoid reducing consumption. Beyond price, there is a significant gap in our understanding of consumer choices. Perceived quality does appear to impact choice; however, more research is needed due to the lack of a recognized definition for cannabis quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00117-0.

Digital Medical Cannabis as Market Differentiator: Second-Generation Artificial Intelligence Systems to Improve Response

Legalized use of cannabis products and the rising interest in their therapeutic benefits have opened up new opportunities for therapy and marketing. However, the marked variability in formulations, administration modes, therapeutic regimens, and inter- and intra-subject responses make the standardization of medical cannabis-based regimens difficult. Legalization has made the cannabis market highly competitive and lowered the revenue margins. This study reviews some of the challenges in medical cannabis use and difficulties in standardizing its therapeutic regimens that hinder maximizing its beneficial effects. The development of tolerance toward cannabis and low adherence to chronic administration further impair its long-term beneficial effects. Digital medical cannabis is a cannabis product controlled by a second-generation artificial intelligence (AI) system that improves patient responses by increasing adherence and dealing with tolerance. Second-generation AI systems focus on a single patient's outcome and deal with the inter- and intra-subject variability in responses. The use of digital medical cannabis is expected to improve product standardization, maximize therapeutic benefits, reduce health care costs, and increase the revenue of companies. Digital medical cannabis offers several market differentiators for cannabis companies. This study presents a model for promoting the use of digital medical cannabis and presents its advantages for patients, clinicians, health care authorities, insurance companies, and cannabis manufacturers. Ongoing trials and real-world data on the use of these systems further support the use of digital medical cannabis for improved global health.

A Clinical Framework for Evaluating Cannabis Product Quality and Safety

Increase in medical cannabis use, along with available products, warrants the need for clinicians to be knowledgeable in evaluating the quality of any cannabis product presented in clinical practice. Determining whether a product is regulated within the region is key in assessing overall quality and safety. Regulated products are held to a higher standard including independent testing, contamination mitigation, and concentration limits. Here, we present a clinical framework in evaluating cannabis products to ascertain the quality and regulation level of the product. Evaluation includes assessing the source company, reviewing product details (e.g., type, cannabinoid content, and labeling), and assessing quality control variables such as manufacturing and decontamination processes. The quality of products patients use is an important part of mitigating cannabis-related harms, especially in medically vulnerable patients. Currently, there is a great need to implement widespread standardization and regulations to ensure product quality and safety.

3-Year Follow-up of Lower Risk Cannabis Use Patterns: Evidence from a Longitudinal Survey

OBJECTIVES

Following recommendations from the Lower Risk Cannabis Use Guidelines, we evaluated how lower risk cannabis use (late initiation and low use frequency) was associated with the risk of developing cannabis abuse/dependence over a 3-year follow-up period compared to 12-month abstinence (controls) or higher risk cannabis use (early initiation and higher use frequency). We also explored the effect of cannabis quantity.

METHODS

Data were obtained from the U.S. nationally representative survey, National Epidemiologic Survey on Alcohol and Related Conditions wave I (2001 to 2002) and wave II (2004 to 2005), which included 31,464 respondents with no lifetime history of cannabis abuse/dependence at the first interview. We applied multiple logistic regression and propensity score matching analyses to examine the association between different use patterns at wave I and cannabis abuse/dependence at wave II, adjusting for covariates. Lower risk cannabis use and the transition to higher use frequency were also assessed.

RESULTS

For propensity score analysis, lower risk cannabis use at wave I was associated with higher risk of cannabis use/dependence at wave II compared to controls (odds ratio [OR]: 4.27; 95% confidence interval [95% CI], 1.57 to 11.61); however, there was no association with use frequency increase (OR: 2.52; 95% CI, 0.88 to 7.17). Higher risk use had a greater risk of cannabis use/dependence than controls (OR: 6.27; 95% CI, 2.56 to 15.38) and lower risk use (OR: 2.69; 95% CI, 1.12 to 6.47). Logistic regression analyses showed similar results, except that lower risk use was significantly associated with use frequency increase (OR: 2.49; 95% CI, 1.22 to 5.08). For the lower risk use group, 1 to 3 joints/day of use was significantly associated with cannabis abuse/dependence.

CONCLUSIONS

We found that following recommended use patterns can significantly lower one's risk of cannabis abuse/dependence. However, risk of cannabis abuse/dependence is still 4 times higher than staying abstinent. Updated recommendations on safe cannabis exposure levels are needed to guide cannabis use in the general population after cannabis legalization.

Cannabis Legalization and Adolescent Use of Electronic Vapor Products, Cannabis, and Cigarettes

OBJECTIVES

Cannabis legalization may have unintended consequences, such as effects on prevalence of adolescent use of other substances. We hypothesize that in states that have legalized recreational cannabis (RCL states), electronic vapor product use ("vaping"), cannabis, and cigarette use among adolescents is more prevalent than in states that have only legalized medical cannabis (MCL states) and states that have neither legalized recreational nor medical cannabis (NL states).

METHODS

Data are from the Center for Disease Control's 2017 Youth Risk Behavior Surveillance Survey (n = 107,665), a nationally representative survey of US high school students. We categorized student responses by cannabis legalization status of the state in which they lived at time of survey, then tested associations between cannabis legalization status and adolescent vaping, cannabis, and cigarette use, using logistic regressions.

RESULTS

Students in RCL states were significantly more likely to report current vaping behaviors compared to NL students [odds ratios (OR's) 2.07-2.21]. Students in cannabis-legal states were significantly more likely to report ever or currently using cannabis compared to NL students (OR's 1.27-1.40). MCL students were significantly less likely to report current cigarette smoking (OR = 0.86) compared to NL students.

CONCLUSIONS

Adolescents in cannabis-legal states were more likely to report vaping and cannabis use compared to adolescents in NL states. Public health officials, policymakers, and clinicians should consider the associations between cannabis legalization and adolescent vaping, cigarette, and cannabis use patterns.

Clinical withdrawal symptom profile of synthetic cannabinoid receptor agonists and comparison of effects with high potency cannabis

Synthetic cannabinoid receptor agonists (SCRAs) may be used as an alternative to natural cannabis; however, they may carry a greater risk of problematic use and withdrawal. This study aimed to characterise the withdrawal symptom profile of SCRAs and compare their profile of effect with high-potency herbal cannabis. Global Drug Survey data (2015 and 2016) were used to access a clinically relevant sample of people reporting use of SCRAs >10 times in the past 12-months, a previous SCRA quit attempt, and lifetime use of high-potency herbal cannabis. Participants completed an 11-item SCRA withdrawal symptom checklist and compared SCRAs and high-potency herbal cannabis on their onset and duration of effects, speed of the development of tolerance, severity of withdrawal, and difficulty with dose titration. Participants (n = 284) reported experiencing a mean of 4.4 (95% CI: 4.1, 4.8) withdrawal symptoms after not using SCRAs for >1 day; most frequently reported were sleep issues (59.2%), irritability (55.6%), and low mood (54.2%). Withdrawal symptoms were significantly associated with frequency (>51 vs. 11-50 times per year: IRR = 1.43, 95% CI: 1.16, 1.77, p = 0.005) and quantity (grams per session: IRR = 1.13, 95% CI: 1.05, 1.22, p = 0.001) of SCRA use. Compared to high-potency herbal cannabis, SCRAs were rated as having a faster onset and shorter duration of effects, faster development of tolerance, and more severe withdrawal (p's < 0.001). In conclusion, SCRA withdrawal symptoms are more likely to occur after greater SCRA exposure. The effects of SCRA indicate a more severe withdrawal syndrome and a greater risk of problematic use than natural cannabis.

Effects of marijuana on reproductive health: preconception and gestational effects

PURPOSE OF REVIEW

Recent widespread legalization changes have promoted the availability of marijuana and its increased potency and perceived safety. The limited evidence on reproductive and perinatal outcomes from marijuana exposure is enough to warrant concern and action. The objective of this review is to provide a current and relevant summary of the recent literature surrounding this topic.

RECENT FINDINGS

The available published studies on the effect of marijuana exposure on reproductive health and pregnancy outcomes are conflicting. Human studies are often observational or retrospective and confounded by self-report and polysubstance use. However, the current, limited evidence suggests that marijuana use adversely affects male and female reproductive health. Additionally, prenatal marijuana exposure has been reported to be associated with an increased risk of preterm birth and small for gestational age infants.

SUMMARY

With the increasing prevalence of marijuana use, there is an urgent need for evidence-driven recommendations and guidelines for couples interested in conception, affected by infertility or who are expecting. At this time, no amount of marijuana use during conception or pregnancy is known to be well tolerated and the limited available evidence suggests that the safest choice is to abstain.

Illegal drug market responses to state recreational cannabis laws

BACKGROUND AND AIMS

In the United States, 15 states and the District of Columbia have implemented recreational cannabis laws (RCLs) legalizing recreational cannabis use. We aimed to estimate the association between RCLs and street prices, potency, quality and law enforcement seizures of illegal cannabis, methamphetamine, cocaine, heroin, oxycodone, hydrocodone, morphine, amphetamine and alprazolam.

DESIGN

We pooled crowdsourced data from 2010-19 Price of Weed and 2010-19 StreetRx, and administrative data from the 2006-19 System to Retrieve Information from Drug Evidence (STRIDE) and the 2007-19 National Forensic Laboratory Information System (NFLIS). We employed a difference-in-differences design that exploited the staggered implementation of RCLs to compare changes in outcomes between RCL and non-RCL states.

SETTING AND CASES

Eleven RCL and 40 non-RCL US states.

MEASURES

The primary outcome was the natural log of prices per gram, overall and by self-reported quality. The primary policy was an indicator of RCL implementation, defined using effective dates.

FINDINGS

The street price of cannabis decreased by 9.2% [β = -0.092; 95% confidence interval (CI) = -0.15-, -0.03] in RCL states after RCL implementation, with largest declines among low-quality purchases (β = -0.195; 95% CI = -0.282, -0.108). Price declines were accompanied by a 93% (β = -0.93; 95% CI = -1.51, -0.36) reduction in law enforcement seizures of cannabis in RCL states. Among illegal opioids, including heroin, oxycodone and hydrocodone, street prices increased and law enforcement seizures decreased in RCL states.

CONCLUSIONS

Recreational cannabis laws in US states appear to be associated with illegal drug market responses in those states, including reductions in the street price of cannabis. Changes in the street prices of illegal opioids analyzed may suggest that in states with recreational cannabis laws the markets for other illegal drugs are not independent of legal cannabis market regulation.

Use of highly-potent cannabis concentrate products: More common in U.S. states with recreational or medical cannabis laws

BACKGROUND

Highly-potent cannabis products, e.g., concentrates, entail greater risks of cannabis-related harms than lower-potency products such as plant or flower material. However, little information is available on whether individuals in U.S. states with recreational cannabis laws (RCL) or medical cannabis laws (MCL) are more likely than individuals in U.S. states without cannabis legalization (no-CL) to use highly-potent forms of cannabis.

METHODS

Cannabis-using adults in a 2017 online survey (N = 4064) provided information on state of residence and past-month cannabis use, including types of products used, categorized as low-potency (smoked or vaped plant cannabis) or high-potency (vaping or dabbing concentrates). Multivariable logistic regression models generated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for use of high-potency cannabis products by state cannabis legalization status (RCL, MCL, no-CL).

RESULTS

Compared to participants in no-CL states, participants in RCL states had greater odds of using high-potency concentrate products (aOR=2.61;CI=1.77-3.86), as did participants in MCL-only states (aOR=1.55;CI=1.21-1.97). When participants in RCL states and MCL states were directly compared, those in RCL states had greater odds of using high-potency concentrate products (aOR=1.69;CI=1.27-2.42).

DISCUSSION

Although the sample was not nationally representative and the cross-sectional data precluded determining the direction of effect, results suggest that use of high-potency cannabis concentrates is more likely among those in RCL states. Clinicians in RCL states should screen cannabis users for harmful patterns of use. Policymakers in states that do not yet have RCL should consider these findings when drafting new cannabis laws, including the specific products permitted and how best to regulate them.

Cannabinoids for the treatment of cannabis use disorder: New avenues for reaching and helping youth?

Cannabis use peaks during adolescence and emerging adulthood, and cannabis use disorder (CUD) is associated with a wide range of adverse outcomes. This is particularly pertinent in youth, because the developing brain may be more vulnerable to adverse effects of frequent cannabis use. Combining evidence-based psychosocial interventions with safe and effective pharmacotherapy is a potential avenue to improve youth outcomes, but we lack approved CUD pharmacotherapies. Here, we review new potential avenues for helping youth with CUD, with a particular focus on cannabinoid-based treatments. Evidence from placebo-controlled RCTs suggests synthetic delta-9-tetrahydrocannabinol (THC) decreases withdrawal symptoms, but not cannabis use, in adults with daily cannabis use/CUD, while findings regarding formulations containing THC combined with cannabidiol (CBD) are mixed. Preliminary evidence from two placebo-controlled RCTs in adults with CUD suggests that both Fatty Acid Amide Hydrolase inhibitors and CBD can reduce cannabis use. However, larger trials are needed to strengthen the evidence. Findings from adults point to cannabinoid-based treatments as a potential strategy that should be examined in youth with CUD.

Mechanisms of cannabis impairment: Implications for modeling driving performance

Past research on cannabis has been limited in scope to THC potencies lower than legally available and efforts to integrate the effects into models of driving performance have not been attempted to date. The purpose of this systematic review is to understand the implications for modeling driving performance and describe future research needs. The risk of motor vehicle crashes increases 2-fold after smoking marijuana. Driving during acute cannabis intoxication impairs concentration, reaction time, along with a variety of other necessary driving-related skills. Changes to legislation in North America and abroad have led to an increase in cannabis' popularity. This has given rise to more potent strains, with higher THC concentrations than ever before. There is also rising usage of novel ingestion methods other than smoking, such as oral cannabis products (e.g., brownies, infused drinks, candies), vaping, and topicals. The PRISMA guidelines were followed to perform a systematic search of the PubMed database for peer-reviewed literature. Search terms were combined with keywords for driving performance: driving, performance, impairment. Grey literature was also reviewed, including congressional reports, committee reports, and roadside surveys. There is a large discrepancy between the types of cannabis products sold and what is researched. Almost all studies that used inhalation as the mode of ingestion with cannabis that is around 6% THC. This pales in comparison to the more potent strains being sold today which can exceed 20%. Which is to say nothing of extracts, which can contain 60% or more THC. Experimental protocol is another gap in research that needs to be filled. Methodologies that involve naturalistic (real world) driving environments, smoked rather than vaporized cannabis, and non-lab certified products introduce uncontrollable variables. When considering the available literature and the implications of modeling the impacts of cannabis on driving performance, two critical areas emerge that require additional research: The first is the role of cannabis potency. Second is the route of administration. Does the lower peak THC level result in smaller impacts on performance? How long does potential impairment last along the longer time-course associated with different pharmacokinetic profiles. It is critical for modeling efforts to understand the answers to these questions, accurately model the effects on driver performance, and by extension understand the risk to the public.

GEOGRAPHICAL ACCESS TO RECREATIONAL MARIJUANA

We investigate whether adult marijuana use in Washington responds to increased local access as measured by drive time to the nearest legal marijuana retailer as well as measures of retail density. Using survey data from the Behavioral Risk Factor Surveillance System, we find that as retailers open closer to where they live, more individuals use marijuana and more frequently. These effects are concentrated among young adults (ages 18-26), women, and rural residents. Controlling for distance to the nearest retailer, we find that whether retail density affects marijuana use depends on how it is measured.

Advancing the science on cannabis concentrates and behavioural health

ISSUES

The Cannabis sativa L. plant contains hundreds of phytocannabinoids, but putatively of highest importance to public health risk is the psychoactive cannabinoid delta-9-tetrahydrocannabinol (THC), which is associated with risk for cannabis use disorder, affective disturbance, cognitive harm and psychomotor impairment. Recently, there has been an increase in the use and availability of concentrated cannabis products (or 'concentrates') that are made by extracting cannabinoids from the plant to form a product with THC concentrations as high as 90-95%. These products are increasingly popular nationwide. The literature on these widely available high potency concentrates is limited and there are many unknowns about their potential harms.

APPROACH

This review covers the state of the research on cannabis concentrates and behavioural health-related outcomes and makes recommendations for advancing the science with studies focused on accurately testing the risks in relation to critical public and behavioural health questions.

KEY FINDINGS

Data point to unique behavioural health implications of concentrate use. However, causal, controlled and representative research on the effects of cannabis concentrates is currently limited.

IMPLICATIONS

Future research is needed to explore chronic, acute and developmental effects of concentrates, as well as effects on pulmonary function. We also highlight the need to explore these relationships in diverse populations.

CONCLUSION

While the literature hints at the potential for these highly potent products to increase cannabis-related behavioural health harms, it is important to carefully design studies that more comprehensively evaluate the impact of concentrates on THC exposure and short- and long-term effects across user groups.

The Potential Impact of Legalization of Recreational Cannabis among Current Users: A Qualitative Inquiry

Given legislative initiatives in Rhode Island pertaining to consideration of cannabis legalization for recreational purpose, a qualitative inquiry was conducted regarding anticipated changes in use among recreational cannabis users in Rhode Island. Five focus groups were conducted with recreational cannabis users (N = 31; 6-7 per group). Participants were queried about anticipated impact of legalization on their use patterns. Themes were identified using applied thematic analysis. Participants discussed (1) a desire to maintain the status quo due to satisfaction with local cannabis regulations and their current use behaviors, (2) how and why cannabis use may change, including pros and cons of legalization, and (3) anticipated changes in purchasing behavior given display and legitimacy of legal dispensaries. While participants anticipate use levels and prevalence may remain relatively stable following legislation changes, findings suggest possible changes related to mode of administration and location of use. Public health concerns exist related to high-risk potencies and use of cannabis in edible form; therefore, trialing of new cannabis products has important clinical implications should legalization occur in Rhode Island.

Cannabidiol versus risperidone for treatment of recent-onset psychosis with comorbid cannabis use: study protocol for a randomized controlled clinical trial

BACKGROUND

Cannabis use is an important risk factor for development of psychosis and further transition to schizophrenia. The prevalence of patients with psychosis and comorbid cannabis use (dual diagnosis) is rising with no approved specialized pharmacological treatment option. Cannabidiol, a constituent of the Cannabis sativa plant, has potential both as an antipsychotic and as a cannabis substituting agent. The aim of this study is to evaluate the efficacy of cannabidiol versus a first-choice second-generation antipsychotic (risperidone) in patients with early psychosis and comorbid cannabis use.

METHODS

The study is a phase II randomized, double-blinded, parallel-group, active-comparator clinical trial. We plan to include 130 patients aged between 18 and 64 years with a recent diagnosis of psychosis, comorbid cannabis use, and currently not treated with antipsychotics. The participants will be randomized to seven weeks of treatment with either cannabidiol 600 mg (300 mg BID) or risperidone 4 mg (2 mg BID). Participants will undergo clinical assessment after 1, 3, 5 and 7 weeks, telephone assessment the weeks in between, and a safety visit two weeks after end of treatment. The primary outcomes are cessation of cannabis use (self-reported) and psychotic symptom severity. The secondary outcomes include frequency and quantity of cannabis use, global illness severity, psychosocial functioning, subjective well-being, cognition, sleep, circadian rhythmicity, and metabolomics.

DISCUSSION

The results of this trial can potentially contribute with a new treatment paradigm for patients suffering from dual diagnosis.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT04105231 , registered April 23rd, 2021.

Development and validation of a mouse model of contemporary cannabis smoke exposure

Cannabis is widely used for both recreational and medicinal purposes. Inhalation of combusted cannabis smoke is the most common mode of drug consumption, exposing the lungs to the pharmacologically active ingredients, including tetrahydrocannabinol (THC) and cannabidiol (CBD). While the relationship between cannabis smoke exposure and compromised respiratory health has yet to be sufficiently defined, previous investigations suggest that cannabis smoke may dysregulate pulmonary immunity. Presently, there exist few preclinical animal models that have been extensively validated for contemporary cannabis smoke exposure.

 To address this need, we developed a mouse model with readouts of total particulate matter, serum cannabinoid and carboxyhaemoglobin levels, lung cellular responses, and immune-mediator production.

 Using a commercially available smoke exposure system and a cannabis source material of documented THC/CBD composition, we exposed mice to a mean±sd total particulate matter of 698.89±66.09 µg·L⁻¹ and demonstrate increases in serum cannabinoids and carboxyhaemoglobin. We demonstrate that cannabis smoke modulates immune cell populations and mediators in both male and female BALB/c mice. This modulation is highlighted by increases in airway and lung tissue macrophage populations, including tissue-resident alveolar macrophages, monocyte-derived alveolar macrophages, and interstitial macrophage subpopulations. No changes in airway or lung tissue infiltration of neutrophils were observed. Immune-mediator analysis indicated significant upregulation of macrophage-derived chemokine, thymus and activation-regulated chemokine, and vascular endothelial growth factor within the lung tissue of cannabis smoke-exposed mice.

 This accessible and reproducible smoke-exposure model provides a foundation to explore the impact of chronic cannabis exposures and/or co-exposures with pathogens of clinical relevance, such as influenza.

Validation of the use of contemporary cannabis available on the legal market of known THC/CBD composition in a mouse model of smoke exposure with readouts of lung inflammationhttps://bit.ly/3okHWS4

Exploring the use of cannabis as a substitute for prescription drugs in a convenience sample

BACKGROUND

The use of cannabis as medicine (CaM) both prescribed and non-prescribed has increased markedly in the last decade, mirrored in a global shift in cannabis policy towards a more permissive stance. There is some evidence that cannabis functions as a substitute for prescription drugs, particularly opioids; however, more knowledge is needed on the motives of substitution users, their patterns of use, and perceived effects of substitution use.

AIMS

To explore who substitutes prescription drugs with cannabis, the type of prescription drugs substituted and the type of cannabis used, and the impact that substitution with cannabis has on prescription drug use as well as the motives for substitution in terms of experienced effects and side effects.

METHODS

A self-selected convenience sample was recruited through social media, public media, and patient organizations to take part in an anonymous online survey. Inclusion criteria were 18 years or older and use of cannabis (prescribed or non-prescribed) with a medical purpose.

RESULTS

The final sample included 2.841 respondents of which the majority (91%) used non-prescribed cannabis, and more than half (54.6%) had used CaM with the purpose of replacing a prescribed drug. Compared to non-substitution users, substitution users were more likely to be women and to use CaM in the treatment of chronic pain and other somatic conditions. Pain medication (67.2%), antidepressants (24.5%), and arthritis medication (20.7%) were the most common types of drugs replaced with CaM. Among substitution users, 38.1% reported termination of prescription drug use, and 45.9% a substantial decrease in prescription drug use. The most frequent type of cannabis used as a substitute was CBD-oil (65.2%), followed by 'hash, pot or skunk' (36.6%). More than half (65.8%) found CaM much more effective compared to prescription drugs, and 85.5% that the side effects associated with prescription drug use were much worse compared to use of CaM.

CONCLUSION

CaM is frequently used as a substitute for prescription drugs, particularly opioids. More research is needed on the long-term consequences of use of CaM, including the impact from low and high THC cannabis products on specific somatic and mental health conditions.

Acute effects of high-potency cannabis flower and cannabis concentrates on everyday life memory and decision making

Statewide legislation has increased public access to high-potency cannabis flower and concentrates, yet federal restrictions limit researchers’ access to relatively low-potency whole-plant cannabis. The goal of this study was to examine the acute effects of high-potency cannabis on cognition using a novel methodology. We further sought to compare cognitive effects of high-potency cannabis flower with and without cannabidiol (CBD), as well as cannabis concentrates to cannabis flower. 80 cannabis users were randomly assigned to stay sober or use their funds to purchase one of three high-potency cannabis products: (1) high-potency flower (≥ 20% THC) without CBD, (2) high-potency flower with CBD, (3) high-potency concentrates (≥ 60% THC) with CBD. Participants were observed over Zoom videoconferencing while inhaling their product or remaining sober and then were administered tests of everyday life memory (prospective, source, temporal order, and false memory) and decision making (risky choice framing, consistency in risk perception, resistance to sunk cost, and over/under confidence) over Zoom. High-potency cannabis flower with CBD impaired free recall, high-potency flower without CBD and concentrates had detrimental effects on source memory, and all three products increased susceptibility to false memories. CBD did not offset impairments and concentrates were self-titrated producing comparable intoxication and impairment as flower.

Unknown population-level harms of cannabis and tobacco co-use: if you don't measure it, you can't manage it

BACKGROUND

Nationally representative data of cannabis-tobacco co-use have shown that these substances are closely entwined and have significant adverse health consequences, although population-level harms of co-use are largely unknown. Current epidemiological research does not assess co-use in a manner that has yielded the necessary data to draw conclusions regarding health effects. This has given rise to a hidden population of co-users who go under-served. Therefore, this paper has two aims: (1) to review new challenges in the collection of co-use data due to rapidly changing regulations of cannabis and nicotine products and (2) to provide recommendations for the terminology and assessment of co-use.

ARGUMENT

We argue that: (1) the prevalence of co-use is not being assessed accurately at a population level and (2) changes in legalization have created novel challenges, but without proper monitoring the impact on co-use will go undetected. We propose a three-level tiered set of recommendations for co-use assessments, which includes assessments of cannabis, tobacco and co-use metrics ranging from least burdensome (self-report of co-administered products) to most burdensome (assays, event-level data).

CONCLUSIONS

We propose that clinical studies begin to incorporate cannabis-tobacco co-use assessments to justify better their inclusion in clinical trials and national surveillance surveys. Integration of co-use assessments will aid in understanding the true impact on co-use of the changing cannabis and tobacco/nicotine regulatory environments. Co-use is prevalent and problematic, and the ability to make conclusions about its health outcomes is hindered by lack of nuance in data collection. If you do not measure it, you cannot manage it.

Investigating sex differences in acute intoxication and verbal memory errors after ad libitum cannabis concentrate use

BACKGROUND

An innovative naturalistic at-home administration procedure was used to investigate sex differences in subjective drug effects and verbal memory errors after ad libitum use of high potency state legal market Δ9-tetrahydrocannabinol (THC) concentrate.

METHODS

Regular concentrate users were randomly assigned to ad libitum administration of one of two cannabis concentrate products (70 % or 90 % THC) that they purchased from a dispensary. 65 participants (N = 34 men, N = 31 women) were assessed in a mobile pharmacology lab before, immediately after, and 1 -h after ad libitum concentrate use. Plasma cannabinoids (THC, 11-OH-THC, CBD), subjective drug effects, and verbal memory errors were assessed at all three time points.

RESULTS

Although men and women exhibited similar plasma 11-OH-THC levels across time (p = .10), sex differences were found in plasma THC and CBD after legal market concentrate use, with men displaying significantly higher levels of plasma THC and CBD immediately after cannabis concentrate use (plasma THC [ng/mL]: M_men = 489.88, M_women = 135.08, p < .001; plasma CBD [ng/mL]: M_men = 1.14, M_women = 0.53, p = .04). Despite this, sex differences in subjective effects and verbal memory errors did not emerge, although women reported a steeper decrease in drug liking after use (p = .04).

CONCLUSION

These data provide the first look at sex differences after acute naturalistic cannabis concentrate use, and suggest much higher THC exposure in men versus women, but similar acute drug and impairment effects across the sexes. Further studies are needed to determine the mechanisms (e.g. tolerance, cannabinoid metabolism, smoking topography) behind these findings.