Cannabis Policy Impacts Public Health and Health Equity (2024)
Chapter: Summary
Summary1
More than half of all U.S. states have legalized cannabis,2 fueled by therapeutic use, social acceptance, a desire for relaxed drug policies, enforcement skepticism, potential tax revenues, and racial justice concerns. The commercial markets created by state legalization require the development of complex policies—surrounding cultivation, processing and manufacturing, distribution, marketing, and sales—to promote public health and health equity. Because cannabis is illegal federally, the federal government has had minimal involvement in cannabis policies within the states. The limited federal guidance on cannabis has focused on its sale—not on public health. Further, federal policies have complicated the efforts of state governments to develop cannabis policies that protect public health. These federal policies include the 2018 Agriculture Improvement Act (2018 Farm Bill), which removed hemp and other cannabinoids from the Controlled Substances Act (CSA), creating a lucrative industry for intoxicating cannabis products designated legally as hemp.3 Public health leadership on cannabis policy is needed, not just in those states with legalized cannabis but nationwide.
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1 This summary does not include references. Citations for the content herein are provided in the full report.
2 “Cannabis” is a broad term that can be used to describe products (e.g., cannabinoids, marijuana, hemp) derived from the Cannabis sativa plant. These products exist in various forms and are used for various purposes (e.g., medical, industrial, social). The all-encompassing word “cannabis” has been adopted as the standard terminology within scientific and scholarly communities. The committee uses the term “cannabis” rather than “marijuana” throughout this report.
3 The 2025 Agricultural Improvement Act may include an updated definition of “hemp” to include only nonintoxicating products (see https://crsreports.congress.gov/product/pdf/IN/IN12381 [accessed July 3, 2024]).
STUDY CONTEXT
As of April 24, 2023, 38 states, three territories, and the District of Columbia allowed cannabis for medical use, and as of November 8, 2023, 24 states had passed legislation legalizing adult nonmedical cannabis supply and use for those over 21 years of age.4 In addition, 9 states had approved measures allowing for the sale of products with low delta-9-tetrahydrocannabinol (THC) and high cannabidiol (CBD) in limited medical situations (see Figure S-1). In many cases, cannabis was legalized through ballot initiatives influenced by political campaigns financed by wealthy donors. Cannabis legalization has allowed commercial markets and sales to create a for-profit industry that requires regulation.
Initially, states enacted legislation legalizing medical use out of compassion for patients seriously ill with AIDS or cancer for whom cannabis was thought to ease suffering. As this process unfolded, it was furthered by exaggeration of the medical or therapeutic benefits of cannabis and minimizing of its harms. Cannabis legalization for adult, nonmedical use occurred as the result of greater social acceptance, a desire for less paternalistic drug policies, hopes of eliminating the illegal market and reducing profits of drug dealers, enthusiasm for a source of new tax revenue, and a growing skepticism regarding the effort and expense involved in enforcing cannabis penalties. Social justice was another critical factor, given the large racial inequities in cannabis arrests.
NOTES: CBD = cannabidiol; THC = delta-9-tetrahydrocannabinol. The map does not include state policies instituted in response to the 2018 Agriculture Improvement Act (PL-115-334).
SOURCE: National Conference of State Legislatures, 2024.
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4 Some state medical cannabis laws allow use among those under 21 years of age.
Cannabis use has both benefits and harms. Therapeutic benefits include treating chemotherapy-induced nausea and vomiting (via oral cannabinoids such as nabilone and dronabinol), management of chronic pain in adults, and improving patient-reported spasticity symptoms in multiple sclerosis (via oral cannabinoids such as nabiximols and nabilone). Harms include increased risk of motor vehicle collisions; development of schizophrenia or psychosis (particularly for those with other risk factors); respiratory symptoms, including increased chronic bronchitis; and lower birthweight in offspring exposed prenatally.
The federal government is working on a change to cannabis policy. Under the CSA scheduling of cannabis, botanical cannabis5 is currently categorized as Schedule I, meaning it has a high abuse potential and no accepted medical use. On May 21, 2024, the Drug Enforcement Administration proposed a rule6 that would shift the scheduling of cannabis to Schedule III, meaning it has moderate abuse potential and a currently accepted medical use. Rescheduling would reduce barriers to cannabis research, but it would not legalize it federally, and state medical and adult use programs would remain illegal under federal law. The Food and Drug Administration (FDA) could approve medical use of a botanical cannabis product by prescription, through its drug approval process, but it is unclear whether that will happen. The impact on state cannabis programs remains unclear, as does the impact on public health.
STUDY CHARGE AND APPROACH
The need for a comprehensive public health review of cannabis policy prompted the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health to commission the National Academies of Sciences, Engineering, and Medicine to convene an ad hoc committee charged with describing cannabis and cannabinoid availability in the United States; assessing regulatory frameworks for the cannabis industry, with an emphasis on social equity; and identifying strengths and weaknesses of public health surveillance systems for cannabis. The committee was asked to recommend a harm reduction approach to cannabis policy and set a policy research agenda for the next 5 years. Notably, the committee was not asked to review the health effects of cannabis consumption (the topic of a National Academies report in 2017); rather, the charge to this committee focused on the health implications of cannabis policy. Figure S-2 presents the organization of the report.
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5 Cannabinoid drugs fall within different areas of the CSA. Cesamet™ (nabilone), synthetically derived delta-9-THC in powder form, is Schedule II, and Marinol® (dronabinol), synthetically derived delta-9-THC in liquid form, is Schedule III. Epidiolex, highly purified, naturally derived CBD, is Schedule V.
6 21 CFR Part 1308, https://www.regulations.gov/document/DEA-2024-0059-0001 (accessed July 4, 2024).
The committee interpreted its charge overall as considering a public health approach to cannabis policy. A public health approach aims to improve the health of entire communities, requiring that factors influencing health outcomes for large groups be considered. Among these essential factors are social and health equity. Social and health equity have some commonalities, but also must be distinguished: “social equity” often focuses on addressing racism and other forms of discrimination, while “health equity” refers to creating systems in which all people have an equal opportunity to achieve their health potential. The two concepts are deeply intertwined: achieving health equity requires dismantling systemic inequalities that create barriers to accessing resources and opportunities, barriers that ultimately hinder individuals and communities from reaching their full health potential. Therefore, addressing social justice issues, such as structural racism, directly impacts health equity by disrupting the mechanisms through which health inequities persist. This committee was tasked with developing recommendations for “strengthening a harm reduction approach, which would minimize harms of various regulatory models, including but not limited to social, employment, education, and health impacts.” Harm reduction is a series of approaches that reduce health and safety risks associated with drug use or other behaviors to individuals and society. Although harm reduction services and approaches can have important implications for public health, the committee believed a broader set of recommendations—a public health approach—was needed to encompass the core public health functions.
RECOMMENDATIONS
Review of Cannabis Policy
Policy development is critical to minimizing the potential harms of cannabis use and promoting health equity. Cannabis policies can inform cultivation, manufacturing, marketing and sales, and consumption or use, and regulation can bring about both benefits and harms (Figure S-3).
State policies, coupled with the current ambiguous definition of “hemp” in the 2018 Farm Bill, have led to a largely unregulated market for semisynthetic intoxicating cannabinoids (Box S-1).
BOX S-1
Public Health Challenge Due to the Definition of “Hemp” in the 2018 Agricultural Improvement Act
The 2018 Agriculture Improvement Act (PL-115-334), often called the “2018 Farm Bill,” redefined “hemp” and removed it from the Controlled Substances Act. The 2018 Farm Bill defines “hemp” as
the plant Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers, whether growing or not, with a [delta-9-tetrahydrocannabinol] concentration of not more than 0.3 percent on a dry weight basis. (PL-115-334 § 297A)
The inclusion of cannabinoids and derivatives in this definition has led to the sale of naturally occurring cannabinoids, such as cannabidiol (CBD), delta-9-THC (if the dry weight is less than 0.3 percent), and tetrahydrocannabinolic acid (THCA), as well as semisynthetic intoxicating cannabinoids, such as delta-8-THC. Semisynthetic cannabinoids raise public health concerns because they are not well studied, and the products may contain harmful by-products. For example, delta-8-THC production uses strong acids and solvents such as toluene and heptane.
A booming industry now exists for largely unregulated hemp-derived products, which competes with legal cannabis markets. States are trying to regulate these new products but face legal challenges and inconsistent court rulings. Some states have banned or restricted hemp products, and a group of attorneys general is urging Congress to act.
Recommendation 2-1: Congress should refine the definition of “hemp” to state clearly that no form of tetrahydrocannabinol or semisynthetic cannabinoid derived from hemp is exempt from the Controlled Substances Act.
Several aspects of alcohol and tobacco policy are important for public health protection. These include a state monopoly, restrictions on physical retail availability, pricing, tax strategies, restrictions and requirements for retail operations, product design restrictions and requirements, measures to limit youth access and exposure, and reduction of cannabis-impaired driving.
Alcohol and tobacco are regulated through state and federal policies. The federal government plays a role in public health policies in such areas as product safety, the establishment of limits on advertising, product labeling, and restrictions on sales to those under age 21. Cannabis is more challenging to regulate than are alcohol or tobacco, although the substances have some important shared aspects. The cannabis plant contains over 100 cannabinoids, with plant hybrids having unique and inconsistent chemical profiles and health impacts. Extracts from the cannabis plant can be incorporated into many different products that can be used through many modes of administration, all with different intoxicating profiles. Cannabis concentrates, for example, usually contain more than 60 percent delta-9THC, but some contain more than 90 percent. Some cannabinoids, such as tetrahydrocannabiphorol, are more potent than delta-9-THC.
During this time of rapid change in cannabis legalization, there is a clear need for the federal government to weigh in on behalf of the public’s health. Existing state cannabis policies were developed without a public health strategy. State-to-state variations in regulations limit public health efforts to prevent harmful use. In contrast, some countries, such as Canada and Uruguay, have adopted more measured approaches with stricter government control over cannabis products and how they are sold or consumed. Such stricter regulatory frameworks may better protect public health.
While all states have minimum age requirements for cannabis use (21 years in adult use states), enforcement through random checks—a method proven effective for tobacco and alcohol use—is limited. Advertising restrictions are also weak. Most states allow cannabis advertising with some limitations on who sees it (not necessarily age-restricted) and where it is placed (e.g., not near schools). As a result, millions of children are exposed to procannabis messages. In contrast with stricter countries, some U.S. states permit advertising with enticements such as coupons, health claims, and depictions of product use without limitations on targeting people outside the state or using public platforms such as billboards. Packaging is regulated to prevent child appeal, but with weak enforcement, so cannabis is frequently promoted to young people in the United States.
State-level cannabis legalization is illegal under federal law unless cannabis, like tobacco and alcohol, is removed from the CSA. Still, given that the federal government has been allowing the states to create commercial markets for cannabis, federal agencies could assist those states that have chosen to legalize. The Council on State and Territorial Epidemiologists, a nonprofit organization of member states and territories representing public health epidemiologists that includes the CDC, has guidance and resources on public health surveillance. Similar guidance could be created for other public health functions.
Recommendation 2-2: In conjunction with other federal agencies, the Centers for Disease Control and Prevention should conduct research on and develop best practices for protecting public health for states that have legalized cannabis, drawing from tobacco and alcohol policies. These best practices should encompass marketing restrictions (e.g., on advertising and packing), age restrictions, physical retail and retail operating restrictions, taxation, price restrictions, product design, and measures to limit youth access. Other strategies for protecting public health that warrant identification of best practices include reducing cannabis-impaired driving, promoting state retail monopoly, and encouraging cultivation practices that limit contamination of both products and the environment. The best practices should be reconsidered and updated periodically as new research emerges.
Recommendation 2-3: The National Governors Association, the National Conference of State Legislatures, and other public health stakeholders should develop model legislation concerning best practices related to marketing restrictions (e.g., on advertising and packaging), age restrictions, physical retail and retail operating restrictions, taxation, price restrictions, product design, and measures to limit youth access, as well as strategies for reducing cannabis-impaired driving, promoting state retail monopoly, and encouraging cultivation practices that limit contamination of both products and the environment. Once the Centers for Disease Control and Prevention’s best practices have been developed, they should be incorporated into the model legislation.
Cannabis Use Patterns and Markets
Cannabis use is increasing in many populations. Public perception of risk has declined while availability has surged, leading to a near doubling of past-year cannabis use among adults in the last two decades. Notably, more people have reported daily or near-daily cannabis use than alcohol use in 2022. Cannabis use is socially stratified. Those with a college education
have the lowest prevalence of use; additionally, those at or below the poverty line have a higher prevalence of use than those with two times the federal poverty level. While dried flower remains the most commonly used product, concentrates, edibles, and vape oils are gaining in popularity, with many people using multiple products and administration methods. Moreover, the THC concentration of products consumed today has increased markedly.
Understanding of the dynamics of the legal versus illegal cannabis markets is complicated by the lack of precise data on cannabis consumption in the United States. The limited studies that have been conducted suggest a shift toward purchasing cannabis from legal markets, particularly in states such as Washington and Oregon. Reduction in the size of the illegal cannabis market is shaped by multiple factors, ranging from the regulatory environment to enforcement activities. Reducing the size of the illegal cannabis market takes time.
Core Public Health Functions
Analysis of the core public health functions—assessment, policy development, and assurance—applied to cannabis policy underscores the need for a more comprehensive public health approach in the United States (Box S-2). Public health involvement in policy development is uneven and often limited to traditional public health roles, such as primary prevention. Other policies, such as those related to zoning, marketing restrictions, and product quality testing, also benefit from public health considerations. Public health needs to be fully engaged in all cannabis policy discussions. Inadequate inclusion of public health in cannabis policy decisions has led to poor application of the core public health functions in states that have legalized cannabis for adult or medical use.
Currently, cannabis surveillance data are collected and analyzed by various entities with limited coordination. Despite their limitations, diverse data sources, such as surveys, health records, and mortality statistics, are available, related mainly to the products used. A centralized, adaptable system could identify cannabis-related public health issues rapidly. Consistent use and application of the essential components of a public health surveillance system—data collection, analysis, and dissemination—would create a more comprehensive picture of cannabis use and its health impacts, ultimately informing practical public health actions. The CDC’s cannabis strategy is missing several elements, such as approaches to data dissemination, a link to action, and regular evaluation. Collaboration with federal partners such as the departments of Agriculture and Commerce is also needed to gain an understanding of cannabis cultivation, production, and sales.
BOX S-2
Public Health Approach to Cannabis Policy
Assessment
- Conduct surveillance of or assess and monitor the health impacts of cannabis.
- Investigate the causes of any identified harms from cannabis use.
Policy Development
- Build and mobilize partnerships between cannabis regulators and public health authorities.
- Inform, educate, and empower communities to develop cannabis-related public health campaigns.
- Develop cannabis policies centered on protecting public health that are not influenced by the regulated industry.
- Equitably enforce cannabis policies designed to ensure compliance.
Assurance
- Protect the public from the potential harms of cannabis (accidental ingestion or poisoning, crashes from impaired driving, secondhand smoke, and environmental impacts).
- Protect those who use cannabis from potential harm and ensure access to treatment.
- Build and support a diverse and skilled public health workforce for cannabis policy.
- Improve and innovate cannabis public health functions through ongoing evaluation, research, and continuous quality improvement.
- Build and maintain a strong organizational infrastructure for cannabis and public health.
SOURCE: Adapted from Ghosh, T., M. Van Dyke, A. Maffey, E. Whitley, L. Gillim-Ross, and L. Wolk. 2016. The public health framework of legalized marijuana in Colorado. American Journal of Public Health 106(1):21–27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4695936.
Recommendation 4-1: The Centers for Disease Control and Prevention, in conjunction with its federal, state, tribal, and territorial partners, should create an adaptable public health surveillance system for cannabis. This surveillance system should include, at a minimum, cannabis cultivation and product sales, use patterns, and health impacts. It should also include all the essential components of a public
health surveillance system: a surveillance plan, data collection, data analysis, data interpretation, data dissemination, a link to action, and regular evaluation.
The influence of the burgeoning legal cannabis industry on policy development raises concerns about potential bias. Lobbying efforts by the industry have demonstrably impacted regulations, as seen in Colorado’s opposition to pesticide restrictions and Washington’s thwarted attempts to limit THC concentration. Further complicating matters are documented conflicts of interest, such as revolving-door practices in regulatory bodies (e.g., Colorado) and financial entanglements (e.g., Washington, Ohio). These examples highlight the current lack of safeguards against industry influence, allowing lobbying and conflicts to impede the development of robust public health protections.
Assurance of public health policies in states where cannabis sales are legalized includes consumer protection strategies, but these strategies vary widely in quality control methods and the contaminants tested. The U.S. Pharmacopeia (USP), an independent, scientific nonprofit organization, sets standards for the quality, safety, and purity of various products, including medicines, food ingredients, and dietary supplements. USP has established procedures for testing product identity, composition, and contaminants and for validating analytical methods. Its laboratory testing methods include several cannabinoid compounds. In addition, USP has developed reference standards for ensuring accurate identification and measurement of product constituents and for addressing sampling considerations to improve representative analysis, product labeling, and appropriate packaging and storage conditions. USP is also developing a cannabis inflorescence (flower) monograph for the Herbal Medicines Compendium, which will include scientifically valid methods; information on physical reference standards; and acceptance criteria for establishing the identity of cannabis chemotypes, the content of cannabinoids and terpenes, and limits on contaminants.
Recommendation 4-2: The U.S. Pharmacopeia has established product quality and analytical standards for cannabis inflorescence (flower) and is developing standards for cannabis extracts incorporated into pills and edibles. As these standards are completed, state cannabis regulators should adopt and enforce them to ensure the safety and quality of all legal cannabis products.
Training and public health messaging can improve public knowledge about cannabis. Clinicians report discomfort in discussing cannabis use with patients, which is a problem given that cannabis use impacts clinical care. Cannabis can interact with other drugs and medications, and its
use is a risk factor for chronic disease. The U.S. Preventive Services Task Force recommends screening adult patients for substance use, which would identify cannabis use and could improve clinical care for patients who use cannabis.
Several states require training on regulations, product knowledge, and responsible sales practices for individuals working in retail cannabis sales. Since many people who use cannabis trust cannabis retail staff, staff need to be trained on the health effects and harms associated with cannabis use. The CDC or another public health authority could create an online training model that could be updated regularly.
Recommendation 4-3: State cannabis regulators should require training and certification for all staff at cannabis retail outlets who interact with customers. The training should address the effects of cannabis on humans, prevention of sales to minors, warnings about cannabis-impaired driving, cannabis use in pregnancy, high-concentration or high-potency products, and how to identify signs of impairment. The effectiveness of the training should be assessed and the content updated as new scientific information about the positive and negative impacts of cannabis emerges.
Colorado and other states have developed targeted public health campaigns, which are essential for improving knowledge about cannabis and its potential harms. Developing and evaluating education campaigns is time- and resource-intensive. Leadership from the CDC could help guide the states toward developing campaigns that are more likely to improve knowledge.
Recommendation 4-4: The Centers for Disease Control and Prevention (CDC), in coordination with other relevant agencies, should develop and evaluate targeted public health campaigns directed mainly toward parents and vulnerable populations (e.g., youth, those who are or are likely to become pregnant, adults over age 65) about the potential risks of cannabis; how to identify risky behavior, such as the use of cannabis in combination with alcohol or prescription drugs; and risk mitigation strategies, such as lower-risk use guidelines and safe storage. These public health campaigns should include discouraging unhealthy use, such as the use of cannabis in combination with other substances (e.g., alcohol, tobacco, or drugs), and the increased risk associated with the use of high-concentration or high-potency products.
Continued evaluation of the public health and societal impacts of changes in cannabis policy is critical as the policy landscape rapidly evolves.
Currently, the Office of National Drug Control Policy is prohibited from studying the impacts of cannabis legalization because, as of July 2024, cannabis is classified as a Schedule I substance under the CSA, and botanical cannabis has no FDA-approved medical use.
Recommendation 4-5. Congress should remove restrictions on the Office of National Drug Control Policy (ONDCP) from studying the impacts of cannabis legalization. The ONDCP should be allowed to support research on the impacts of changes in cannabis policy.
Cannabis Policy and Health Equity
Changes in cannabis policy may influence health equity in many ways. Some public health experts have posited that cannabis legalization could reduce social inequities, and therefore the health inequities to which they contribute, by mitigating the adverse consequences of the criminalization of cannabis use, possession, and sales, which have historically been experienced disproportionately by minoritized populations. The commercial cannabis industry also may contribute to health inequities. Disproportionate marketing to minoritized groups or overconcentration of retailers within lower-income communities or communities of color may lead to unequal distribution of the health impacts of cannabis use. The committee evaluated the impacts of cannabis policy on health equity by considering the harms of cannabis prohibition within the criminal justice system; a critique of the social equity programs adopted in some states; and the impacts of cannabis policies on the social determinants of health, economic stability, education access and quality, health care access and quality, neighborhoods and the built environment, and the social and community context.
Racial inequalities in arrests contribute to health inequities since the stigma of a criminal record can influence the health of that individual and their family. The collateral consequences following criminal encounters can limit economic security, employment, housing, business, and educational opportunities. Throughout the liberalization of cannabis policy, racial disparities in cannabis arrests may have increased. Comparing cannabis possession arrests in 2002–2004 and 2017–2019, arrests decreased for White people and increased for Black people. Evaluation of the impact of changes in cannabis policy on equity is hampered by a lack of data on cannabis arrests and sentencing. The committee had difficulty evaluating cannabis arrests because of incomplete data, the challenges of which have been discussed in prior reports of the National Academies.
Recommendation 5-1: Jurisdictions responsible for the enforcement of cannabis laws should endeavor to regularly gather and report detailed
data concerning the use of criminal enforcement tools to enforce cannabis policies. These tools include:
- arrests,
- sentences,
- incarceration (pre- and postadjudication), and
- diversion programs (e.g., drug courts, law enforcement–assisted diversion, treatment programs).
These data should be available to the public and should include details about the specific cannabis violation (e.g., impaired driving, illicit trafficking, distribution to minors, possession, possession with intent to distribute, probation or parole violation) and the demographics of those in contact with law enforcement (e.g., race, sex, age, criminal history).
Most states that have legalized cannabis use and/or sales have implemented social equity measures to help those harmed by cannabis policing (22 of 24 adult-use states as of January 2024). These measures include criminal justice reforms, such as record relief and resentencing; technical and financial assistance for cannabis businesses; and community reinvestment. While these initiatives are well intended, implementation challenges must be addressed to ensure that they are meeting their stated goals and not having unintended consequences.
Recommendation 5-2: State cannabis regulators should systematically evaluate and, if necessary, revise their cannabis social equity policies to ensure that they meet their stated goals and minimize any unintended consequences. Policy makers should meaningfully engage affected community members when developing or revising these policies.
Record relief provisions that clear a criminal of cannabis-related charges can help improve access to employment, educational opportunities, and housing. In states that have implemented record relief provisions for cannabis offenses, automatic or government-initiated relief has proven to be more effective than petition-based relief.
Recommendation 5-3: Where states have legalized or decriminalized adult use and sales of cannabis, criminal justice reforms should be implemented, and records automatically expunged or sealed for low-level cannabis-related offenses.
Changes in cannabis policy have complex and sometimes contradictory impacts on neighborhoods and the social environment. Studies suggest that cannabis retail outlets may be more likely to be located in communities with
higher rates of poverty or communities of color, which could contribute to health inequities.
Cannabis legalization has brought opportunities to address issues regarding access to health care. As of 2022, punitive prenatal drug use policies existed in nearly half of U.S. states. Drug testing in pregnancy is applied inequitably, particularly to communities of color, and may deter those who use cannabis from seeking prenatal care. Pregnant people who use cannabis will benefit from clinical and social support; education about fetal risk; and referral to nonjudgmental, evidence-based interventions or specialty treatment as needed, rather than being arrested or reported to child protective systems.
PUBLIC HEALTH IMPACTS OF CANNABIS POLICY
One of the most prominent public health concerns related to cannabis policy is the rise of high-concentration and high-potency THC products. The risks associated with THC consumption increase as the dose increases, and legalizing products that deliver high doses potentially increases adverse cannabis-related harms. Indeed, high-concentration THC products are associated with a higher risk of psychosis and cannabis use disorder. More research is urgently needed to describe the relationship between THC dose and adverse effects to better inform public policy.
The committee also reviewed 14 systematic reviews evaluating the public health impacts of cannabis policy. The variations in legalization across states provide an opportunity to conduct policy research. Better capture of the differences in how policies are implemented among the states and improvements in policy analysis databases and surveillance systems are needed to support analysis of essential outcomes of policy changes. The committee found limited or only suggestive evidence that the perceived risk of cannabis use declines after legalization, that use among adults increases, that traffic collisions increase, and that hospital visits related to cannabis use increase. For all other outcomes, the committee judged the evidence to be insufficient. The committee then used this information and the analysis presented throughout this report to develop a research agenda (Box S-3).
Recommendation 6-1: The National Institutes of Health; the Centers for Disease Control and Prevention; state, local, and tribal health authorities; and private entities should support a research agenda focused on:
- public health outcomes of different approaches to cannabis regulation,
- efficacy of tests used to determine cannabis impairment,
BOX S-3
Cannabis Policy Research Agenda
Public health outcomes of different approaches to cannabis regulation: It is critical to examine how state and local cannabis regulations—including those related to licensing, zoning, product types, product additives, advertising, and pricing—influence public health outcomes and health equity. Aspects of this needed research include investigating how these regulations affect cannabis use patterns (age of initiation, frequency, intensity, product type, concentration, and administration method), rates of heavy cannabis use, cannabis use disorder diagnoses, cannabis-related emergency department visits and hospitalizations, cannabis-related comorbid physical health and mental health outcomes, and traffic-related injuries and deaths associated with cannabis use. Studying how THC caps influence use patterns and health outcomes could improve guidelines and inform effective regulations.
Efficacy of tests used to detect cannabis impairment: Blood tests for THC, which are commonly used in law enforcement and employment screening, do not distinguish between recent and past use. Additionally, validation of field sobriety tests and objective, unbiased, and practical methods for discriminating between drivers who are or are not impaired by cannabis is critical in ensuring equitable enforcement of laws on driving under the influence.
Health effects of cannabis use by specific populations: It is critical to understand the specific health risks and benefits of cannabis use across different populations. Examples of populations critical to monitor include:
- pregnant persons, considering both potential risks to the fetus and potential benefits for managing pregnancy ailments;
- youth and young adults because of the impacts of cannabis on the developing brain;
- veterans, including how cannabis use may interact with posttraumatic stress disorder symptoms and overall mental health; and
- older adults and adults with chronic conditions, including the use of cannabis and cannabinoids for managing chronic conditions and the potential risks of drug interactions.
Health effects of emerging cannabis products: There is a great need to understand the health risks of emerging synthetic and semisynthetic cannabinoids and high-concentration products. In particular, research into dose–response relationships for different cannabis products is needed.
Mitigation of the risks of cannabis use: Evaluating risk-mitigation strategies for cannabis use and their effectiveness is crucial so that public health can understand which educational and other strategies are most effective at reducing problematic use and minimizing harm.
- health effects of cannabis use (by product, amount, and frequency) by specific populations,
- health effects of emerging cannabis products, and
- mitigation of the risks of cannabis use.
CONCLUSION
The rapidly changing landscape of cannabis legalization—with state-by-state variations, an influx of new products, and federal policy changes with uncertain implications—presents a complex challenge for public health. This report considers a public health approach to cannabis policy, which is critically needed to protect public health and promote health equity. While ongoing research is crucial, applying the core public health functions—assessment, policy development, and assurance—now will lead to better and more consistent policies for cannabis legalization and improved public health and health equity.
