According to a 2010 study from the University of Florida College, these combination drinkers are more likely to become highly intoxicated and four times as likely to drive drunk.

Energy drinks may decrease sensitivity to the effects of alcohol intoxication and raise the risk of potential serious harm. Mixing alcohol and energy drinks increases the risk of drunk-driving accidents and injuries. The caffeine in energy drinks reduces a drinker's perception of drunkenness, although the actual level of impairment is the same.