A major U.S. review warns states are flying blind on public-health impacts as cannabis legalization accelerates
As cannabis legalization continues its rapid expansion across the United States, new evidence suggests that state governments may not have the tools needed to understand what comes next. Researchers(https://link.springer.com/article/10.1186/s12889-025-25720-7) from the University of Connecticut have completed the most comprehensive scoping review to date, analyzing 110 publications to determine what should actually be monitored after adult-use cannabis becomes legal.
Their central message is blunt: despite the political momentum behind legalization, the country lacks a uniform and reliable system capable of tracking its public-health consequences. Without stronger monitoring, states risk missing critical warning signs—especially for young people and marginalized communities.
How the Review Was Conducted
The research team screened more than 4,000 articles and policy documents before narrowing the selection to 110 sources that explicitly offered recommendations for cannabis-outcome monitoring. They included empirical studies, policy analyses, commentaries, dissertations, and meta-analyses—reflecting the fragmented nature of cannabis research in the U.S.
The review focused exclusively on adult-use cannabis, not medical programs, because the authors argue these policy regimes have distinct goals, populations, and market structures. This distinction matters: only a small proportion of U.S. cannabis consumers use cannabis exclusively for medical reasons, and adult-use laws have far broader public-health implications.
Seven Major Areas States Must Monitor
After synthesizing the findings, the researchers identified seven key domains that states should track to understand the real impact of legalization.
1. Cannabis Use, Attitudes, and Perceptions
Experts agree that monitoring cannot stop at tracking prevalence alone. States need detailed insights into:
- frequency of use (days/month; times/day),
- quantity consumed,
- THC potency and product type (flower, oils, edibles),
- age of initiation,
- sources of cannabis,
- co-use with alcohol and other substances,
- demographic differences,
- and shifting perceptions of harm.
Because attitudes and perceived risks are strongly correlated with consumption, especially among youth, their measurement is considered essential.
2. Public Safety and Criminal Legal System Impacts
Cannabis legalization reshapes multiple public-safety indicators, but states often track only a narrow subset. The literature recommends monitoring:
- impaired-driving cases,
- roadway injuries and fatal crashes,
- unintentional pediatric exposures,
- school-based incidents,
- arrests, convictions, and citations tied to cannabis,
- and changes in law-enforcement workloads.
These datapoints can reveal whether legalization reduces justice-system disparities or unintentionally creates new ones.
3. Health and Psychosocial Outcomes
The authors emphasize that cannabis-related health effects must be observed across both acute and long-term indicators. Recommended measures include:
- rates of cannabis use disorder (CUD),
- mental-health outcomes (anxiety, psychosis risk, mood disorders),
- cardiovascular events linked to cannabis,
- cannabis hyperemesis syndrome,
- and drug poisoning trends.
Given mixed evidence on youth cannabis prevalence post-legalization, monitoring health outcomes directly is considered crucial.
4. Market Practices and Industry Regulation
Changes in the cannabis market may affect public behavior as much as legalization itself. The review recommends tracking:
- product potency trends,
- pricing—including illicit-market prices,
- methods of production and cultivation,
- advertising practices,
- number and density of retail outlets,
- packaging standards and child-safety warnings,
- tax revenue and allocation of funds.
Advertising practices aimed at young consumers emerged as a particular concern.
5. Hospitalizations, Emergency Visits, and Health-Services Utilization
Emergency-department data provides some of the earliest signals of emerging harms. States are encouraged to track:
- ED visits related to cannabis,
- poison-control center calls,
- hospital admissions by condition,
- postmortem toxicology,
- admissions for CUD and mental-health conditions,
- and use of counseling or treatment programs.
These data help quantify risks tied to high-potency products and evolving consumption patterns.
6. Social Equity Outcomes
Although equity is central to many state legalization frameworks, the review found surprisingly limited monitoring. Few sources track whether legalization:
- reduces racial disparities in arrests,
- improves access to treatment for minority communities,
- changes the location or concentration of cannabis retailers in disadvantaged neighborhoods,
- or influences broader quality-of-life indicators.
Researchers warn that failing to track equity outcomes could allow systemic disparities to deepen unnoticed.
7. New and Emerging Monitoring Methods
Traditional surveys alone can no longer capture the complexity of the cannabis landscape. Innovative approaches recommended include:
- wastewater analysis to detect population-wide THC metabolites,
- social media and search-trend monitoring,
- machine-learning tools to detect real-time patterns,
- environmental metrics, such as water and power demand from cultivation sites,
- and economic models for measuring long-term costs and benefits.
The authors argue that only a multi-source monitoring system can provide an accurate national picture.
Why Today’s Monitoring Systems Fall Short
The review outlines several structural weaknesses across current U.S. public-health data systems:
- National datasets lack state-level granularity, making it difficult to evaluate policy impacts regionally.
- Survey questions are inconsistent, outdated, or do not reflect modern consumption methods like vaping or concentrates.
- Self-reported data excludes key populations, such as people experiencing homelessness or those who are incarcerated.
- Regulatory landscapes differ dramatically across states, complicating comparisons.
- Most states lack the funding, staff capacity, or inter-agency coordination needed to build integrated monitoring frameworks.
These issues collectively limit policymakers’ ability to evaluate legalization’s real-world consequences.
Youth: the Most Sensitive Indicator
Although the review notes mixed findings on adolescent use post-legalization, it highlights heightened vulnerability among youth due to ongoing brain development.
Studies suggest that perceptions of harm strongly shape use patterns in teenagers and emerging adults. When legal markets normalize cannabis—and high-potency products become more widely available—the risk for problematic use may rise.
The Importance of Baseline Data
One of the strongest recommendations is deceptively simple: states should establish monitoring systems beforelegalization goes into effect.
Without before-and-after comparisons, states cannot reliably determine whether legalization increased, decreased, or simply shifted cannabis-related harms.
Global Context: Why Better Monitoring Matters Everywhere
As the cannabis landscape evolves globally, these findings align with broader international patterns. Canada’s growing fiscal reliance on cannabis tax revenue highlights how national budgets increasingly depend on accurate industry tracking (https://thecannex.com/canada-cannabis-tax-revenue-2025/). Israel’s long-term medical-cannabis registry illustrates the value of consistent, standardized data collection over time (https://thecannex.com/israel-medical-cannabis-trends-2011-2025/).
Debates around delta-8 THC (https://thecannex.com/delta-8-thc-cannabis-prohibition-study/) and shifting social-media policies—including Meta lifting its cannabis-search ban (https://thecannex.com/meta-lifts-cannabis-search-ban-facebook-instagram/)—underscore how rapidly the informational environment is changing. Cultivation research such as mainlining and high-stress training (https://thecannex.com/cannabis-mainlining-high-stress-training-yield-architecture/) alongside genetic studies linking cannabis use to mental-health risks (https://thecannex.com/genetic-links-cannabis-use-mental-health-chronic-disease/) further demonstrate why policymakers increasingly need comprehensive, real-time datasets.
Where Cannabis Policy Goes Next
The study argues that future progress depends on:
- coordinated national surveillance systems,
- better funding for data infrastructure,
- more rigorous and diverse analytical methods,
- inclusion of traditionally overlooked populations,
- and multi-source approaches integrating clinical, behavioral, market, environmental, and digital data streams.
Legalization may be transforming the American cannabis market—but without better monitoring tools, its public-health impact remains difficult to measure.
