Sleepless nights are quite common, especially if you have a sleep disorder like sleep apnea. You often wake up the next day tired, irritated, and unfocused. You sleepwalk the whole day, and drink liters of coffee without any relief.
Because of this problem, sleeping pills are one of the most commonly abused prescription drugs. People who have problem getting and staying asleep are told by their doctors to take medication. Once they do, they become dependent. They build up a tolerance to the point that they have to take higher doses just so the drug would work.