Sleepless Nights Make for Grumpier Brains

A new study finds that a lack of sleep causes the brain's emotional centers to dramatically overreact to negative experiences.

A shutdown of the prefrontal lobe -- a brain region that normally keeps emotions under control -- is the reason for heightened emotional response in sleep-deprived people.

Reporting in the Oct. 23 issue of the journal Current Biology, the team said its study is the first to determine, at the neural level, why lack of sleep can lead to emotionally irrational behavior and may help improve understanding of the link between sleep disruptions and psychiatric disorders.

"This adds to the critical list of sleep's benefits," Matthew Walker of the University of California, Berkeley, said in a prepared statement. "Sleep appears to restore our emotional brain circuits, and, in doing so, prepares us for the next day's challenges and social interactions. Most importantly, this study demonstrates the dangers of not sleeping enough. Sleep deprivation fractures the brain mechanisms that regulate key aspects of our mental health."