Marijuana (Cannabinoids)

Smoking marijuana increases the risk of driving accidents

Are you surprised?

First, the details.

  • Researchers from Canada examined self-reported collision involvement over 12 months and compared it to marijuana smoking.

And, the results.

  • The odds of involvement in a driving accident were significantly higher among cannabis users, and those who reported driving after cannabis use.
  • There was some evidence for a dose-response relationship.

The bottom line?
It’s pretty simple. People who drive after smoking pot are more likely to be involved in a collision.

Others have discovered a correlation between the degree of impairment, the drug dose, and the blood concentration of tetrahydrocannabinol (THC).

In fact, 6 European countries have established blood levels for THC intoxication between 0.3 and 2 ng/mL.

2/29/08 23:08 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.