An estimated eight and a half million adults in the United States experiences sleepwalking.
The disorder is caused by an interruption in REM sleep but typically disappears in adulthood.
Experts on sleep in the United States did a recent study that showed there are twice as many adults that sleep walk as once thought.
Sleepwalking is more likely to occur in adults that had the disorder as children or have taken drugs designed to treat depression.
The rates for sleepwalking when from one in fifty to one in twenty-five, that is double the rate originally believed for walking while asleep in the United States.