THC More Common Than Alcohol In Severe Crashes: UMass Chan Study

WORCESTER, MA — THC was the most common drug found in drivers in severe crashes, according to a UMass Chan Medical School study of U.S. cities. Kavita Babu, MD, co-authored the report that examined the role drugs played in serious motor vehicle crashes at the start of the COVID-19 pandemic.

The report is based on toxicological analyses of blood specimens from people seriously or fatally injured in roadway accidents. Data for the study was collected from more than 7,200 road users, including drivers, cyclists, and pedestrians, over an 18-month period beginning in late January 2020, according to UMass Chan.

The study found that 56 percent of road users seriously or fatally injured tested positive for one or more drugs. The most common was cannabinoids at 25.1%, with alcohol coming in next at 23.1%. Stimulants were the third most common with 10.8% and opioids next with 9.3%.

The study's abstract stated that: "Future similar research...could be used for monitoring changes in drugged driving over time and could inform traffic safety stakeholders to better tailor impaired driving countermeasures for particular regions or types of road users."

The study was the "largest research effort to date in the United States to conduct independent toxicological analyses of blood specimens from roadway users were seriously or fatally injured in motor vehicle crashes." While past studies focused on drivers, this research was expanded to include pedestrians, cyclists, passengers, and others.

The full report is available from the National Highway Traffic Safety Administration.