Colorado: State-Mandated Review on High-THC Products Yields Inconclusive Results

Denver, CO: Researchers affiliated with the Colorado School of Public Health failed to reach any definitive conclusions regarding the potential health risks associated with the use of high-THC products, following the completion of a two-year review of available data. 

Researchers reviewed over 450 relevant studies. They identified only “limited” evidence supporting that high-THC products are associated with an elevated risk of substance abuse or dependence. Similarly, they found little data to substantiate fears that young people are more susceptible to “adverse physical or mental health outcomes” after using concentrated THC products. 

Investigators did identify “a moderate amount of evidence that high-concentration THC cannabis products are associated with adverse mental health outcomes for those with preexisting mental health conditions.” NORML has long opined that those with a family history of psychiatric illness or with a clinically high risk of psychosis may be especially vulnerable to experiencing adverse events from cannabis.

The study’s findings are similar to those of a 2021 state-sponsored review by the Massachusetts Cannabis Control Commission which found “insufficient evidence” to recommend a THC potency cap on legal marijuana products.

State lawmakers mandated the Colorado study following the passage of HB 1317 in 2021. Other provisions in that law limit the amount of THC concentrates that may be purchased by certain patients and require recommending physicians to assess patients’ “mental health history,” even in cases where patients have no pre-existing or underlying mental health issues.

NORML has opined against the imposition of THC potency caps for state-regulated products because of concerns that doing so would drive the production and sale of these products underground and bolster the unregulated marketplace. 

Full text of the report, “A Scoping Review on Health Effects of High-Concentration THC Products: Findings on Key Policy Questions,” is available from the Colorado School of Public Health. Additional information is available from the NORML Fact Sheet, ‘THC Potency Concerns: Are Stronger Products More Problematic?’ Further information is available from NORML’s white paper, ‘Cannabis, Mental Health, and Context: The Case for Regulation.’