A nightcap might help you drift off—but don't expect a good night's sleep for your trouble. In the 1970s, researchers gave subjects each between one and six drinks a half-hour to an hour before bedtime. Those who had more booze fell asleep quicker, but during the second half of the night, they experienced what researchers called a "rebound effect": They woke more often and didn't sleep as deeply, the Washington Post explains in an excerpt from the blog Gaines, on Brains. Why?
Experts theorize that at first, the body compensates for the alcohol; as the night goes on, however, the brain "overcompensates," writes Jordan Gaines, worsening our sleep. The metabolization process wakes us up as gamma-aminobutyric acid, an inhibitory neurotransmitter, is turned into glutamate, an excitatory neurotransmitter which affects our sleep. Binge drinking is sure to prevent a good night's sleep. As for a small nightcap, Gaines recommends that if you have it, have it early, so the body has time to process it and your sleep is undisturbed. That will improve your waking life: As Fast Company has put it, "Hate productivity? Enjoy that nightcap." In related news, hangovers cost the US economy $160 billion annually.