Scientists have unearthed a better way to test for recent cannabis use, which could revolutionize how authorities determine impairment. Standard THC blood tests often fail to accurately reflect impairment levels, particularly among frequent cannabis users. The University of Colorado researchers found that analyzing the molar metabolite ratio of THC to THC-COOH in the blood provides more precise results.
In their study, participants underwent a driving simulator exercise after smoking cannabis, with blood tests taken before and 30 minutes after smoking. The results showed that a 0.18 cut-off ratio indicated recent cannabis use with 98 percent specificity. This method far surpassed the accuracy of testing for THC alone, which yielded only 80 percent accuracy.
While promising, the study acknowledges limitations such as timing variations and the need for further research on impairment levels. Despite these, the new method presents a significant step towards developing standardized tests for cannabis impairment, a critical aspect for criminal investigations and ensuring highway safety. Ongoing efforts seek to refine and expand this groundbreaking approach, offering hope for more reliable assessments of cannabis-related impairment on the roads.
Jaeger, K. (2024, January 30). Scientists develop new method to test for recent marijuana use with 96% accuracy in federally funded driving simulation study. Marijuana Moment.
Melani, D. (2024, January 3). New research gains ground in detecting recent cannabis use. CU Anschutz Newsroom.
