A Live Science report examines the impact of sleep deprivation on everything from emotions to hallucinations.

Indeed, there are more nightmarish side effects to sleep deprivation.

If a person is deprived of sleep, it can lead to “tremendous emotional problems,” said Dr. Steven Feinsilver, the director of the Center for Sleep Medicine at Icahn School of Medicine at Mount Sinai in New York City. “Sleep deprivation has been used as a form of torture,” he said.

There isn’t a clear definition of exactly how long a person must go without sleep, or how little sleep a person has to get to be considered sleep-deprived, and different people need different amounts of sleep, so there may be no universal definition of “sleep deprivation.” Rather, a person is considered sleep-deprived if they get less sleep than they need to feel awake and alert, researchers say.

But still, research over the years has shown that people can be physically and psychologically damaged from not getting enough sleep, said David Dinges, a professor of psychology and the director of the Unit for Experimental Psychiatry at the University of Pennsylvania.

Read the full story at www.livescience.com