Alcohol plus cannabis is one of the most frequently detected combinations of drugs in car accidents.

Alcohol and cannabis taken together may increase the effect of the cannabis, a new study finds.

This may be why, in car accidents, alcohol plus cannabis is one of the most frequently detected combinations of drugs.

Taking both drugs together significantly increases the levels of cannabis’ main psychoactive ingredient, THC (tetrahydrocannabinol) in comparison to taking cannabis alone.

For the research, 19 adults either took doses of cannabis or a placebo.

Both were combined with alcohol.

Tests demonstrated significantly higher levels of THC when the same amount of cannabis was taken with alcohol rather than with a placebo.

Dr Marilyn A. Huestis, the study’s first author, said:

“The significantly higher blood THC and 11-OH-THC [median maximum concentration] values with alcohol possibly explain increased performance impairment observed from cannabis-alcohol combinations.

Our results will help facilitate forensic interpretation and inform the debate on drugged driving legislation.”

The study was published in the journal Clinical Chemistry (Huestis et al., 2015).

→ The effects of regular cannabis use on creativity.

Cannabis user image from Shutterstock