Study: Marijuana Least Likely Of All Substances Studied To Increase Vehicle Crash Risk


By Steve Elliott
Hemp News

Marijuana is the least likely to elevate the risk of automobile crashes of all substances studied, according to research recently published in the scientific journal Accident Analysis and Prevention.

Scientists at Columbia University performed a study to determine the connection between drug use and fatal auto crash risk, reports Paul Armentano at the National Organization for the Reform of Marijuana Laws (NORML). The authors reported that marijuana, at 1.83, had the lowest crash odds ratios of all substances identified.

Depressants were most likely to be associated with crash risk, with an estimated odds ratio of 4.83. Estimated odds ratios for other drug categories were 3.57 for stimulants, 3.41 for "polydrug use" (excluding alcohol), and 3.03 for narcotics.

The odds ratio for marijuana is similar to that reported in a 2012 meta-analysis of 66 separate studies which estimated that cannabis is associated with a "nominally increased" risk of accident, with an estimated odds ratio of 1.25. In that study, antihistamines (1.12) and the antibiotic penicillin (1.12) were close to cannabis in crash risk odds.

Other studies looking at fatal crash risks found far higher ratios for alcohol. Drivers who reported consuming two or more alcoholic drinks in a six-hour period prior to driving were nearly eight times more likely to suffer a car crash-related injury compared to non-drinkers, according to a 2004 study published in the journal Epidemiology.

The Columbia researchers didn't assess the risk of alcohol consumption alone in the new study, but they did report that alcohol use combined with controlled substances increased subjects' risk of fatal accidents more than 20-fold.

(Photo: West Coast Leaf)