Marijuana use might double the chances of driving accidents

Marijuana use linked to crashes

Marijuana use linked car accidents

Research suggests if you use marijuana you may be at twice the risk of having a motor vehicle accident, compared to people who don’t use cannabis.

Researchers at Columbia University performed a meta-analysis of nine epidemiologic studies, finding people who tested positive for marijuana were twice as likely to have a car accident. The chances of a mishap while driving increased with frequency of marijuana use and concentration of the drug in the urine.

The scientists say the finding is important because of findings from a 2009 National Survey on Drug Use and Health that showed over 10 million people age 12 or older had driven under the influence of an illicit drug in the year prior to the survey.

Guohua Li, MD, DrPh, professor of Epidemiology at Columbia University's Mailman School of Public Health, and senior author says the finding should be interpreted with caution, because the research doesn’t prove cause.

Marijuana most frequently found drug linked to car crashes

Li says, “…if the crash risk associated with marijuana is confirmed by further research, this is likely to have major implications for driving safety and public policy. It also would play a critical role in informing policy on the use of medical marijuana”.

In the study, marijuana was the most frequently found drug detected following a motor vehicle accident.  More than 11% of the general driver population tested positive for non-alcohol drugs. In twenty-eight percent of fatalities, non-alcohol drugs were found in the urine or bloodstream of drivers.

In 8 out of 9 studies, the researchers found marijuana users were more like to be involved in a driving accident. Li says, “…it is urgent that we better understand the role of marijuana in causing car accidents”, that would have implications for public policy for medical marijuana. The study suggests marijuana users are twice as likely to have a driving accident, compared to non-users.

Source: Columbia University Mailman School of Public Health
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