"Sleeping pills will knock you out for the entire night."
In clinical studies, people taking sleeping pills slept only about 20 to 40 minutes more than those taking a placebo. "But if you ask people how much more sleep they got while taking the pills, they tend to overestimate," says Michael A. Grandner, PhD, research associate at the Center for Sleep and Circadian Neurobiology at the University of Pennsylvania. He adds that the sleep quality of pill-taking patients tended to be sound, but it was still shallower than nonmedicated sleep. Grandner and other researchers are currently looking into why people give sleeping pills more credit than they may deserve. "People with insomnia have more brain activation during the night," he says, "and we think the pills may be working on that process—not by helping them sleep more—but by changing brain processes like memory that cause them to simply think they're getting more rest."