Harvard researchers have reportedly found a new method of identifying those whose performance has been compromised by THC, the main psychoactive compound in cannabis that causes a “high”.
Harvard researchers came up with a potentially highly effective technique called functional near-infrared spectroscopy (fNIRS), a form of non-invasive brain imaging procedure, to accurately detect individuals with THC disorders.
As more states in the USA opening up to legal cannabis use, the study authors felt it was important to differentiate between reduced and mild THC intoxication, in order to make the roads safer.
Lead author Jodi Gilman, a researcher in the Center for Addiction Medicine, MGH, and an associate professor of psychiatry at Harvard Medical School, said:
“Our research represents a new direction for impairment testing in the field.
Our aim was to determine whether a cannabis disorder could be detected by brain activity at an individual level.
This is a critical issue because a 'breath tester' approach does not work for detecting a disorder in cannabis, making it very difficult to objectively assess THC damage during a traffic stop.”
The study – and the results from Harvard
In the study, 169 people underwent the brain imaging procedure (fNIRS) after receiving oral THC or a placebo.
Those who reported intoxication after taking THC showed an increased oxygenated hemoglobin concentration (HBO) compared to those who reported low or no intoxication.
Senior author and principal investigator A. Eden Evins, founder and director of the Center for Addiction Medicine, said:
Identifying acute disorders from THC intoxication through wearable brain imaging could be an essential tool in the hands of police officers in the field.
The accuracy of this method was confirmed by the fact impairment determined by machine learning models using only information from fNIRS matched self-report and clinical evaluation of impairment 76 percent of the time.
Companies are developing breath analysis devices that measure only exposure to cannabis, but no impairment of cannabis.
We need a method that will not penalize medical marijuana users or others with insufficient amounts of cannabis in their system to impair their performance. While it needs further investigation, we believe brain-based testing could provide an objective, practical and much-needed solution.
Sources including Canex (EN), doi (EN), Harvard (EN), Nature (EN)
