Drink?: The New Science of Alcohol and Health

by David J. Nutt

The sedative effect works for around four hours. At this point, you may wake up with a headache and perhaps with lights flashing in your eyes, feeling alert and unhappy, and find it hard to get back to sleep. If you don’t wake up, you’re likely to sleep badly or fitfully. This is happening because your brain knows being intoxicated is potentially dangerous—so it doesn’t want to be intoxicated. As soon as you started to drink the previous night, your brain started to change. Because alcohol blocks glutamate receptors, your brain up-regulated the glutamate system to compensate for this, by increasing the quantity of glutamate receptors. Then, as your blood alcohol level goes down during the night, you’re left with too many receptors and so too much glutamate activity. And that is why you are too awake and alert, and why the world seems too bright, too noisy, too much.