About 40 percent of high schools start before 8 a.m., which contributes to chronic sleep deprivation among teens, according to the American Academy of Pediatrics. Chris Waits/Flickr hide caption

itoggle caption Chris Waits/Flickr

About 10 percent of Americans have chronic insomnia. iStockphoto hide caption

itoggle caption iStockphoto

Teenagers' sleep patterns may be a clue to their risk of depression. iStockphoto hide caption

itoggle caption iStockphoto

Though scientists have identified sleepwalking triggers, the condition is still a bit of a mystery. Victoria Alexandrova/iStockphoto.com hide caption

itoggle caption Victoria Alexandrova/iStockphoto.com

Sleep researchers say parents of a new child can be a risk for long-term insomnia. Timothy M. Black/iStockphoto.com hide caption

itoggle caption Timothy M. Black/iStockphoto.com