Nowadays, Americans average less than the recommended 8 hours of
sleep per night. A nightcap, or drink taken before bed, is
thought by many to help with sleep. However, alcohol actually
interferes negatively with sleep as your body processes it.
Throw an energy drink mixer in and it is chemically worse news
for your rest. "Just as with caffeine, your brain proves
remarkably adept at adapting itself and responding to the
ethanol molecules jamming up its receptors and interfering with
neuron firings. It takes a bit for the brain to catch up,
though." (Braun's Buzz via Lifehacker) The brain's receptors and
pathways try to reclaim equilibrium, which can wreak havoc on
general resting and on crucial REM sleep. REM stands for rapid
eye movement - it is the stage of sleep during which the brain
gets its most critical rest and rejuvenation. If you've had
caffeine, too, this adds to the situation. Caffeine is a drug
that can take up to 5 hours to break down half a dose. Throw
caffeine into the mix (as many fans of vod