A new study has found that drivers with a threshold level of marijuana's psychoactive ingredient in their bloodstream show increased weaving within their driving lane, in a fashion similar to individuals with a .08 level of alcohol.
Published in Drug and Alcohol Dependence, the study also found an additive effect from drinking alcohol and smoking marijuana, as those using both substances weaved within lanes even if their blood levels of THC and alcohol were below the threshold for impairment for each substance in isolation. The study was funded by the National Institute on Drug Abuse (NIDA), the Office of National Drug Control Policy (ONDCP) and the National Highway Traffic Safety Administration.
Researchers did find that unlike with alcohol, marijuana did not increase the speed of weaving or the number of times a driver left the driving lane.
Get the latest information on Counseling and other valuable topics at the most extensive educational experience for professionals working in addiction prevention, treatment, aftercare, and management, with dedicated topics for clinicians, executives, and marketers.