High Potency Cannabis
With a legal market of cannabis products has come the wide distribution of manufactured products containing much higher levels of THC than what has been historically found in the plant.
Science to date shows a dose-response relationship between THC concentration and health consequences. Manufactured cannabis products may add further risks due to additives, residues and contaminants.
Researchers and policy makers are working to better understand these risks. This page contains recent reports and summaries that describe what we know so far.
Reports
High THC Policy | Final Report: Exploring Policy Solutions to Address Public Health Challenges of High THC Products (2022)
To address the emerging public safety challenge of increasingly available high-THC products (e.g. dabs, wax, concentrates), the WA State Health Care Authority was directed by ESSB 5092 (2021) to contract with the University of Washington’s Addictions, Drug & Alcohol Institute (ADAI) to identify areas of common ground and consensus, and develop recommendations for state policies related to cannabis concentration and mitigating detrimental health impacts.
The final report to the legislature, published in December 2022, describes recommendations for state policies based on the perspectives of WA stakeholders, research evidence on public policies designed to mitigate harms associated with non-medical use of high THC cannabis products and other legally commercialized health-compromising products, and cannabis policies that have been considered or adopted in North America.
Related resources:
- Report Addresses Mental Health Risks of High-THC Cannabis (UW Medicine piece about this report and CERP Director Beatriz Carlini, PhD, MPH
- Leaked Report Shows Heightened Scrutiny of Marijuana’s Rising Potency (Bloomberg article about this report)
Report citation:
Washington State Health Care Authority (HCA) & University of Washington Addictions, Drug & Alcohol Institute (ADAI). Washington State HCA report to the legislature. High THC policy | Final report: Exploring policy solutions to address public health challenges of high THC products. Engrossed Substitute Senate Bill 5092; Section 215(55); Chapter 334; Laws of 2021. Olympia, WA; Washington State Health Care Authority, December 2022.
Cannabis Concentration and Health Risks: A Report for the Washington State Prevention Research Subcommittee (2020)
This consensus statement and report, published in November 2020, was developed by a workgroup of research scientists from the University of Washington (UW) and Washington State University (WSU) with the intent of providing policy makers with a summary of the current evidence on topics of public health importance related to cannabis concentration.
Download the report and additional resources:
- Consensus statement and report (pdf)
- Research brief about the report’s findings (pdf)
- Presentation slides (pptx, 12MB) featuring key points from the report and suitable for a general audience
Workgroup members include:
- Beatriz Carlini, PhD, MPH, UW, Addictions, Drug & Alcohol Institute (Chair)
- Celestina Barbosa-Leiker, PhD, WSU, Health Sciences
- Carrie Cuttler, PhD, WSU, Department of Psychology
- Julia Dilley, PhD, MES, Multnomah County Health Department and State of Oregon Public Health Division
- Caislin Firth, PhD, MPH, UW, Addictions, Drug & Alcohol Institute
- Kevin Haggerty, PhD, MSW, UW, School of Social Work
- Jason Kilmer, PhD, UW, Department of Psychiatry & Behavioral Sciences
- Mike McDonell, PhD, MS, WSU, College of Medicine, Behavioral Health Innovations
- Nephi Stella, PhD, UW, Departments of Pharmacology and Psychiatry & Behavioral Sciences
- Denise Walker, PhD, UW, Innovative Programs Research Group
- Dale Willits, PhD, WSU, Criminal Justice & Criminology
- Liz Wilhelm, Prevention WINS
Additional Resources
Other groups have also worked to describe what we know so far about high-potency cannabis and the implications for public health and policy decisions. Links to these reports and summary statements can be found below.
- Cannabis Policy: Public Health and Safety Issues and Recommendations, March 2021 (U.S. Senate Caucus on International Narcotics Control)
- Public Policy Statement on Cannabis (American Society of Addiction Medicine)
- Clearing the Smoke on Cannabis: Edible Cannabis Products, Cannabis Extracts, and Cannabis Topicals (Canadian Centre on Substance Use and Addiction)
- THC Concentration in Colorado Marijuana: Health Effects and Public Health Concerns (CO Department of Public Health & Environment)
- Letter to the California Cannabis Advisory Committee
- High Tetrahydrocannabinol Cannabis and Effects on the Body: More Research Needed (Cannabis Control Commission, Massachusetts, October 2021)