Mixing alcohol and energy drinks leads to negative consequences that are a public health concern, according to a new paper. Combining the two beverages makes a person want to drink more and masks the signs of drunkenness, Time reports.

“When people mix energy drinks with alcohol, people drink more than they would if they had just consumed alcohol, which is associated with a cascade of problems,” says paper author Cecile Marczinski of Northern Kentucky University.

In Advances in Nutrition, Marczinski says drunk driving is the main public health concern. The caffeine in an energy drink makes a person look and feel more coordinated and balanced than they actually are. This leads some drinkers to believe they are not drunk, she says. Mixing alcohol and energy drinks can also lead to brain damage in teens, as well as increased emergency department visits and hospitalizations, Marczinski notes.

A study published in July 2014 found mixing energy drinks with alcohol increases the urge to drink. People who consume the mixture may drink more alcohol than they planned, according to the researchers.

Energy drink manufacturers in the United States are no longer allowed to make high-caffeine drinks with alcohol, but young people are mixing their own drinks, such as combining Red Bull and Jägermeister liquor.

A study published in 2013 concluded drinking alcohol with an energy drink is more dangerous than drinking alcohol alone. Researchers found college students tended to drink more heavily, and become more intoxicated, on days they used both energy drinks and alcohol, compared with days when they only drank alcohol.