Changes in California cannabis exposures following recreational legalization and the COVID-19 pandemic

Associations of Local Cannabis Control Policies With Harmful Cannabis Exposures Reported to the California Poison Control System

BACKGROUND

Cannabis exposures reported to the California Poison Control System increased following the initiation of recreational cannabis sales on 1 January 2018 (i.e., "commercialization"). We evaluated whether local cannabis control policies adopted by 2021 were associated with shifts in harmful cannabis exposures.

METHODS

Using cannabis control policies collected for all 539 California cities and counties in 2020-2021, we applied a differences-in-differences design with negative binomial regression to test the association of policies with harmful cannabis exposures reported to California Poison Control System (2011-2020), before and after commercialization. We considered three policy categories: bans on storefront recreational retail cannabis businesses, overall restrictiveness, and specific recommended provisions (restricting product types or potency, packaging and labeling restrictions, and server training requirements).

RESULTS

Localities that ultimately banned storefront recreational retail cannabis businesses had fewer harmful cannabis exposures for children aged <13 years (rate ratio = 0.82; 95% confidence interval = 0.65, 1.02), but not for people aged >13 years (rate ratio = 0.97; 95% confidence interval = 0.85, 1.11). Of 167 localities ultimately permitting recreational cannabis sales, overall restrictiveness was not associated with harmful cannabis exposures among children aged <13 years, but for people aged >13 years, a 1-standard deviation increase in ultimate restrictiveness was associated with fewer harmful cannabis exposures (rate ratio = 0.93; 95% confidence interval = 0.86, 1.01). For recommended provisions, estimates were generally too imprecise to detect associations with harmful cannabis exposures.

CONCLUSION

Bans on storefront retail and other restrictive approaches to regulating recreational cannabis may be associated with fewer harmful cannabis exposures for some age groups following statewide commercialization.

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

Objectives

With the legalization of cannabis in New Jersey on April 21, 2022, including the licensing of cannabis dispensaries, concerns have arisen about potential adverse events related to cannabis use. Here, we explore temporal trends and risk factors for cannabis-related harm in both adult and pediatric cannabis-related visits at a tertiary care academic institution.

Methods

We performed a retrospective chart review and temporal trend analysis via the electronic health record from May 1, 2019 to October 31, 2022, covering 2 years before, and 6 months after, cannabis legalization in New Jersey. The pediatric charts identified were analyzed for root causes of adverse events, and changes in the frequency of specific unsafe practices since cannabis legalization were tracked.

Results

We found that adult cannabis ED-related visits significantly increased during the COVID-19 pandemic and remained higher than pre-pandemic levels for the remainder of the study periods, without a significant change upon legalization. Pediatric rates of cannabis-related ED visits did not vary significantly during the study period. The vast majority of visits for children aged 0-12 years were related to accidental cannabis exposures-often a household member's edibles-whereas most visits for older children stemmed from intentional cannabis use.

Conclusion

This project highlights the unintended consequences of wider cannabis access in New Jersey. Notably, cannabis use increased even before its legalization, presumably in response to the COVID-19 pandemic and its attendant mental health effects. Rates of cannabis use disorder and its highlight of other concurrent psychiatric disorders are important topics for both clinicians and lawmakers to consider.

Reported exposures to derived cannabis products in California before and after the 2018 federal reclassification of hemp

BACKGROUND

As of June 2023, a majority of states had legalized the sale of cannabis, which past research has found to be associated with increased exposures. In 2018, a change in federal policy increased access to cannabidiol (CBD) and derived psychoactive cannabis products, but there has been limited study of reported exposures following this change.

METHODS

This observational retrospective study analyzed exposures involving synthetic cannabinoid receptor agonists (SCRAs) and derived cannabis products, including CBD, reported to the California Poison Control System (CPCS) from 2010 to 2022. We focused primarily on potential shifts in reported exposures before and after the implementation of the 2018 Farm Bill, which removed products derived from hemp from the Controlled Substances Act. We reviewed and hand-coded individual call records to assess reported exposures over time and their characteristics, and conducted interrupted time series analysis to assess whether exposure counts changed after policy interventions.

RESULTS

Reported CBD exposures significantly increased following the federal reclassification of hemp products. Exposure reports were most common among young children and for edibles. Exposure reports provided limited information about derived psychoactive cannabis products.

CONCLUSIONS

Our findings suggest a need for improved data collection regarding derived psychoactive cannabis products, as well as potential public health value in modifying packaging regulations and in providing additional guidance to parents to help prevent CBD exposures.

Proximity to Cannabis Retailers and Recent Cannabis Use among a Diverse Sample of California Adolescents

Background: As of May 2023, 23 states and Washington, DC have legalized the sale of cannabis for adults aged 21+, and 38 states, three territories, and D.C. have legalized medical cannabis. Exposure to cannabis retailers could increase adolescent cannabis use. Few studies have examined the impact of residential proximity to cannabis retailers on adolescent cannabis use, and previous findings are inconsistent. Methods: This study examined associations between proximity to cannabis retailers and past 30-day cannabis use. Data were from Project Cal Teens, a statewide survey of California adolescents regarding cannabis-related opinions/behaviors (N = 1406, mean age = 15.5 years, 48% female, 38% Hispanic/Latinx, 33% White, 15% Asian/Pacific Islander, 10% Black/African American, 5% Other/Multiracial). Participants were recruited via schools/social media in 2018-2020. Results: For every additional 5 driving miles to the nearest cannabis retailer, the risk of past 30-day cannabis use was reduced by 3.6% [IRR: 0.964; 95% CI: 0.935-0.994]. For every additional 5 miles from a licensed retailer, the risk of past 30-day cannabis use was reduced by 4.3% [IRR: 0.957; 95% CI: 0.926-0.989]. Interaction analyses revealed that among Hispanic/Latinx students, every 5 miles from a licensed retailer was associated with an 11.9% reduction in the risk of past 30-day cannabis use [IRR: 0.881; 95% CI: 0.820-0.945]. Conclusions: As the number of cannabis retailers in the U.S. increases with the continued legalization of adult cannabis use, research examining the effects of these policies on underage use is crucial. Interventions could include enforcement of zoning laws in/near residential areas to reduce accessibility of adolescents to cannabis retailers.

Trends in cannabis-related emergency department visits and hospitalizations among children aged 0-11 years in Canada from 2015 to 2021: spotlight on cannabis edibles

BACKGROUND

Cannabis poisonings among children are of public health concern. Existing evidence from the US and from four provinces in Canada (Quebec, Ontario, Alberta, British Columbia) indicate an increase in pediatric cannabis-related poisonings since the legalization of cannabis. This study evaluates trends in cannabis-related poisoning pediatric emergency department (ED) visits and hospitalizations in Canada and addresses a gap in literature by describing trends and context around cannabis edible-related poisoning cases using data from a Canadian sentinel surveillance system.

METHODS

Mixed-methods using data from two administrative data sources and one injury/poisoning sentinel surveillance system to estimate age-specific rates of cannabis-related poisonings ED visits (Ontario and Alberta), edible-related events (sentinel surveillance Canada), and hospitalizations (Canada with the exception of Quebec) among children between the ages of 0 to 11 from 2015/2016 to 2021. Annual absolute changes were calculated to quantify the magnitude of change between each age-specific rate. Joinpoint regression was used for trend analysis. A thematic analysis was completed to gain a better understanding of cannabis edible-related poisoning cases in the ED.

RESULTS

The pediatric age-specific rates for cannabis-related poisoning ED visits (average annual percent change (AAPC) Ontario: 98.2%, 95% CI: 79.1, 119.2; AAPC Alberta: 57.4%, 95% CI: 36.7, 81.2), hospitalizations (AAPC: 63.4%, 95% CI: 42.0, 87.9) and cannabis edible-related events (AAPC: 122.8%, 95% CI: 64.0, 202.6) increased significantly from 2015 to 2021. Almost half of all pediatric edible-related events involved gummy edible products (48.8%, n = 143). Based on the thematic analysis, 88% cannabis edible-related events were attributed to inadvertent ingestion due to access to such products or lack of safe storage practices.

CONCLUSION

Age-specific rates of cannabis-related poisoning ED visits (Ontario and Alberta) and hospitalizations (Canada with the exception of Quebec) have increased since cannabis legalization, with the largest increase in rates occurring from 2019 to 2020. A similar increase in the rate of cannabis edible-related cases from sentinel surveillance data underscores the importance of monitoring this outcome. Public health messaging and national public health promotion strategies targeted towards raising awareness on the risks associated with consuming illegal cannabis and safe storage of cannabis could help mitigate cannabis poisonings among children.

Pleiotropic loci for cannabis use disorder severity in multi-ancestry high-risk populations

Cannabis use disorder (CUD) is common and has in part a genetic basis. The risk factors underlying its development likely involve multiple genes that are polygenetic and interact with each other and the environment to ultimately lead to the disorder. Co-morbidity and genetic correlations have been identified between CUD and other disorders and traits in select populations primarily of European descent. If two or more traits, such as CUD and another disorder, are affected by the same genetic locus, they are said to be pleiotropic. The present study aimed to identify specific pleiotropic loci for the severity level of CUD in three high-risk population cohorts: American Indians (AI), Mexican Americans (MA), and European Americans (EA). Using a previously developed computational method based on a machine learning technique, we leveraged the entire GWAS catalog and identified 114, 119, and 165 potentially pleiotropic variants for CUD severity in AI, MA, and EA respectively. Ten pleiotropic loci were shared between the cohorts although the exact variants from each cohort differed. While majority of the pleiotropic genes were distinct in each cohort, they converged on numerous enriched biological pathways. The gene ontology terms associated with the pleiotropic genes were predominately related to synaptic functions and neurodevelopment. Notable pathways included Wnt/β-catenin signaling, lipoprotein assembly, response to UV radiation, and components of the complement system. The pleiotropic genes were the most significantly differentially expressed in frontal cortex and coronary artery, up-regulated in adipose tissue, and down-regulated in testis, prostate, and ovary. They were significantly up-regulated in most brain tissues but were down-regulated in the cerebellum and hypothalamus. Our study is the first to attempt a large-scale pleiotropy detection scan for CUD severity. Our findings suggest that the different population cohorts may have distinct genetic factors for CUD, however they share pleiotropic genes from underlying pathways related to Alzheimer's disease, neuroplasticity, immune response, and reproductive endocrine systems.

The Impact of Recreational Cannabis Legalization on Cannabis Use and Associated Outcomes: A Systematic Review

Background

Recreational cannabis legalization has become more prevalent over the past decade, increasing the need to understand its impact on downstream health-related outcomes. Although prior reviews have broadly summarized research on cannabis liberalization policies (including decriminalization and medical legalization), directed efforts are needed to synthesize the more recent research that focuses on recreational cannabis legalization specifically. Thus, the current review summarizes existing studies using longitudinal designs to evaluate impacts of recreational cannabis legalization on cannabis use and related outcomes.

Method

A comprehensive bibliographic search strategy revealed 61 studies published from 2016 to 2022 that met criteria for inclusion. The studies were predominantly from the United States (66.2%) and primarily utilized self-report data (for cannabis use and attitudes) or administrative data (for health-related, driving, and crime outcomes).

Results

Five main categories of outcomes were identified through the review: cannabis and other substance use, attitudes toward cannabis, health-care utilization, driving-related outcomes, and crime-related outcomes. The extant literature revealed mixed findings, including some evidence of negative consequences of legalization (such as increased young adult use, cannabis-related healthcare visits, and impaired driving) and some evidence for minimal impacts (such as little change in adolescent cannabis use rates, substance use rates, and mixed evidence for changes in cannabis-related attitudes).

Conclusions

Overall, the existing literature reveals a number of negative consequences of legalization, although the findings are mixed and generally do not suggest large magnitude short-term impacts. The review highlights the need for more systematic investigation, particularly across a greater diversity of geographic regions.

Cannabis positivity rates in 17 emergency departments across the United States with varying degrees of marijuana legalization

BACKGROUND

Many states in the United States have progressed towards legalization of marijuana including decriminalization, medicinal and/or recreational use. We studied the impact of legalization on cannabis-related emergency department visits in states with varying degrees of legalization.

METHODS

Seventeen healthcare institutions in fifteen states (California, Colorado, Connecticut, Florida, Iowa, Kentucky, Maryland, Massachusetts, Missouri, New Hampshire, Oregon, South Carolina, Tennessee, Texas, Washington) participated. Cannabinoid immunoassay results and cannabis-related International Classification of Diseases (ninth and tenth versions) codes were obtained for emergency department visits over a 3- to 8-year period during various stages of legalization: no state laws, decriminalized, medical approval before dispensaries, medical dispensaries available, recreational approval before dispensaries and recreational dispensaries available. Trends and monthly rates of cannabinoid immunoassay and cannabis-related International Classification of Diseases code positivity were determined during these legalization periods.

RESULTS

For most states, there was a significant increase in both cannabinoid immunoassay and International Classification of Diseases code positivity as legalization progressed; however, positivity rates differed. The availability of dispensaries may impact positivity in states with medical and/or recreational approval. In most states with no laws, there was a significant but smaller increase in cannabinoid immunoassay positivity rates.

CONCLUSIONS

States may experience an increase in cannabis-related emergency department visits with progression toward marijuana legalization. The differences between states, including those in which no impact was seen, are likely multifactorial and include cultural norms, attitudes of local law enforcement, differing patient populations, legalization in surrounding states, availability of dispensaries, various ordering protocols in the emergency department, and the prevalence of non-regulated cannabis products.