Marijuana increases the risk of car accidents

January 13, 2022

I’ve been prescribing medical marijuana (MM) since 2016 when it became legal in New York. We still lack controlled clinical trials of MM for the treatment of migraines. Most of my patients who find MM useful report that it relieves nausea or anxiety, helps them go to sleep and sometimes relieves pain. Others find that taking it daily prevents migraines. CBD alone can be also helpful, but most patients need a combination of CBD and THC as well in order to obtain a therapeutic effect.

Like any other drug, MM can have side effects. One of them is cognitive impairment. A study just published in the New England Journal of Medicine describes the effect of recreational marijuana legalization in Canada on injuries to car drivers. The researchers studied drivers treated after a motor vehicle collision in four British Columbia trauma centers from 2013 through 2022. They discovered that after legalization, the number of moderately injured drivers with a THC level above the legal limit doubled. The largest increase was seen in older and male drivers.

This is relevant to the users of MM as well. From now on, I will caution my patients not to drive after taking any THC-containing products. Just like with alcohol, you don’t need to have a blood level above the legal limit to slow your reflexes.

Written by
Alexander Mauskop, MD
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