The Four-Loko Effect.

There have been recent reports of mass hospitalizations for alcohol intoxication following consumption of fruit-flavored, caffeinated, alcoholic drinks-especially concerning one brand in particular: Four Loko. Caffeine was quickly determined to be the culprit. In accordance with a directive by the Food and Drug Administration, caffeine was removed from Four Loko and similar beverages. However, the evidence that caffeine played a prominent role in widespread displays of intoxication is far from clear. Rather, it is likely that Four Loko-type drinks are especially effective as intoxicants because they provide alcohol in an unusual context. It has been known for many years that drug tolerance partially results from an association between drug-paired stimuli and the drug effect. When these stimuli are altered, the drug-experienced individual does not display the expected tolerant response to the drug-rather, an enhanced (i.e., nontolerant) response is seen. Four Loko and similar beverages may be especially effective intoxicants because they provide a very novel flavor context for alcohol. A recent announcement by the manufacturer of Four Loko suggests (either by design or happenstance) appreciation of the contribution of alcohol-associated cues to alcohol tolerance.