Have you ever woken up so confused you've mistaken a water bottle for a telephone, or the closet for a toilet? If so, you might be among the one in seven people estimated to suffer from a sleep disorder called "confusional arousal," reports MedPage Today. Or to put it a different way, "sleep drunkenness." These incidents occur when a person's deep sleep is interrupted; they wake up, but the brain continues to snooze, explains LiveScience. "It's like they are totally drunk—they don't know where they are or what they are doing," says study co-author Dr. Maurice Ohayon of Stanford. It's common in children and isn't your garden variety morning grogginess—sufferers are hard to wake up and often have no memory of an episode, which can include violence.
Researchers found 15% of the 19,000 adults in the study suffered from the disorder, with more than half of those afflicted reporting an episode at least once a week. Their answers regarding sleep habits, mental illness, and medications allowed researchers to pinpoint some risk factors, including sleep disorders, alcoholism, PTSD, antidepressants, and too much or too little sleep. About 30% reported being "sleep drunk" for 15 minutes or longer after waking, which raises concern about workers who nap on the job—or, say, pilots and doctors. "You can hurt yourself physically," and hurt someone else, Ohayon tells CNN. (Researchers recently found seven hours of sleep is the best amount.)