What happens when you mix cannabis and alcohol?

A combo you should never mix with driving.

Man driving at night with text overlay reading "Mixing cannabis and alcohol; do you know the impact?"Have you ever heard of polyconsumption? It may sound like a complex medical term, but the Centers for Disease Control and Prevention has a pretty simple definition: Polyconsumption is “the use of more than one drug, also known as polysubstance use. This includes when two or more intoxicating substances are taken together, either intentionally or unintentionally.” Essentially, every time you drink a beer and smoke a joint, you are poly-consuming.
With polysubstance use on the rise, we want to ensure everyone is aware of the physiological and behavioral impacts of combining the two drugs. Using cannabis and alcohol together enhances the effects of each, causing increased impairment, such as:

  • Slowed reaction time.
  • Loss of coordination and problem-solving skills.
  • Distorted perception of time, distance and speed.

So, why does it matter? Why do CDOT and law enforcement agencies believe this is an issue we need to address? While the use of cannabis is legal in Colorado, driving while intoxicated is not.

The Colorado Division of Criminal Justice (DCJ) published a report in January 2023 that analyzed 2020 data from more than 21,000 impaired driving cases filed in Colorado. Researchers followed the cases from arrest to final court outcome. The DCJ report found:

  • 18% of impaired drivers arrested tested positive for multiple substances. The most common combination was alcohol and Delta 9-THC, which is the primary psychoactive component of cannabis.
  • The second most common pairing was alcohol combined with other drugs such as cocaine, methamphetamine, sedatives and opioids.
  • 75% of individuals with detected Delta-9 THC also had some other substance present. Alcohol was the most common co-occurring substance.

This is not just a Colorado issue. According to the Insurance Institute for Highway Safety, “A third of drivers (nationwide) who drink alcohol and use marijuana at the same time report getting behind the wheel within two hours of consumption.”

Research also shows that users are more likely to drive — or take other risks — after using both substances than after consuming marijuana alone.

Impairment-related fatalities are on the rise in Colorado. About one-third of traffic deaths involve an impaired driver. It’s our mission to educate and inform Coloradans to make the right decision to never drive high, but the bottom line is it’s up to you. With everything on the line from a DUI to a life lost, what decision will you make?