Marijuana, Cocaine Have Contrasting Effects On Driving Performance, Study Says

Victoria, British Columbia:  Cannabis and cocaine have contrasting effects upon psychomotor performance, according to survey data published in the current issue of the journal Traffic Injury Prevention.

Investigators at British Columbia’s Center for Addiction Research surveyed the attitudes and driving behaviors of adults in drug treatment that had a history of driving under the influence of cannabis, cocaine, or alcohol.  Authors reported that pot’s acute effects were more likely to make respondents drive more cautiously or refuse driving altogether.

“When comparing negative physical effects and reckless style of driving with frequency of driving under the influence of cannabis or cocaine, increased negative physical effects from cannabis were inversely related to frequency of driving under the influence of cannabis,” investigators concluded.  “In terms of driving behavior, cautious or normal driving was commonly reported for cannabis, whereas reckless or reduced driving ability was frequently reported for cocaine.”

For more information, please contact Paul Armentano, NORML Deputy Director, at:  Full text of the study, “Driving behavior under the influence of cannabis or cocaine,” appears in Traffic Injury Prevention.  Additional information on marijuana use and on-road accident risk appears in the NORML report “Cannabis and Driving: A Scientific and Rational Review,” available online at: