The Secret Life of Sleep Eaters

Sept. 7, 2010— -- It could be a scene from a horror movie called "Night of the Hungry Zombies." A sleepwalker enters the kitchen, grabs anything within reach -- cookies, crackers, even a dish scouring pad -- and chows down, sometimes taking food back to bed.

Only this is a real life nightmare for 43-year-old Anna Ryan, and one million other Americans. And it has nothing at all to do with hunger.

"There's a compulsion to eat. But it's not a hunger-driven behavior," said Dr. Carlos Schenck, a psychiatrist and an expert in sleep research.

He was one of the first to complete a major study on Sleep Related Eating Disorder (SRED), after spending the past 20 years trying to understand it.

"We've had patients consume cat food sandwiches. They've put coffee grounds, Coca-Cola, and eggshells in a blender and consume it. They eat Elmer's Glue. They chew on chunks of frozen pizza and then try to swallow it. They're like sleeping zombies, just walking around headless. Except that they have a mouth to feed."

Ryan is what doctors call a parasomniac, someone with a sleep disorder that leads to an abnormal event during sleep. These odd behaviors can range from walking to having sex, known as sexsomnia, to acts of aggression and violence, all while asleep.

What may trigger the unusual acts of parasomniacs like Ryan is the shutdown of the brain's frontal lobe during sleep, Schenck said. The frontal lobe is the seat of judgment. Brain scan studies and other research shows that when people doze, their frontal lobe switches off. At the same time, the remainder of the brain may become more active and direct the sleep eater to immediately seek food.

"They can get up, they see their environment," Schenck said. "They know where the kitchen is. But they have no judgment, no inhibition. And that's the problem."