Cannabis edibles impair driving ability hours after consumption, study finds

A study published in ‘JAMA Network Open’ reveals that consuming cannabis edibles, such as gummies, significantly impairs driving ability even several hours after ingestion. Conducted at a Canadian hospital with 40 participants, the research found that doses of 10mg and 20mg of THC led to increased lane deviation (SDLP), slower reaction times, and inconsistent vehicle speeds.

Notably, the impairment persisted two to five hours after consumption. Researchers observed that blood THC concentrations in participants remained within or below the legal limits used by law enforcement in some U.S. states, yet driving performance was still compromised. This discrepancy poses a challenge for road safety and law enforcement, as the delayed absorption and prolonged effects of edibles make them harder to detect and predict compared to inhaled cannabis.

In the United States, the American Trucking Associations has expressed concerns regarding public safety and the potential weakening of drug testing protocols following the recent reclassification of marijuana to Schedule III. Experts emphasize that the unpredictable nature of edible cannabis consumption complicates the interpretation of biological measurements for roadside enforcement.