Potential Test for Traffic Stops.

• Position: CANNABIS IMPAIRMENT

Because THC has been shown to impair cognitive and psychomotor performance essential to safe driving, a tool to identify acute impairment is vital to police officers in the field, note researchers at Massachusetts General Hospital, who have found a noninvasive brain imaging procedure to be an objective and reliable way to identify individuals whose performance has been impaired by THC, the psychoactive ingredient in cannabis.

The technique uses imaging technology known as functional near-infrared spectroscopy (fNIRS) to measure brain activation patterns that correlate to impairment from THC intoxication. As reported in the journal Neuropsychopharmacology, the procedure could have significant implications for improving highway and workplace safety.

"Our research represents a novel direction for impairment testing in the field," says lead author Jodi Gilman, investigator in the Center for Addiction Medicine and associate professor of psychiatry at Harvard Medical School. "Our goal was to determine if cannabis impairment could be detected from activity of the brain on an individual level. This is a critical issue because a 'breathalyzer' type of approach will not work for detecting cannabis impairment, which...