Study: 'Sleep drunkenness' plaguing some with post-sleep confusion

Do you ever wake up and feel confused or forget what happened before you went to sleep? A new study shows more people than ever suffer from "sleep drunkenness."

Stanford University researchers claim 15 percent of their subjects reported having an episode of the disorder within the past year.

Doctors said if you have it, you might do things like answer the phone instead of turning off the alarm, experience amnesia, or be very confused after waking up.

When it comes to finding a cause, doctors said an overwhelming majority of the people with sleep drunkenness also take psychotropic drugs or have another medical problem. It can be caused by other untreated sleep disorders such as sleep apnea, restless leg syndrome and insomnia.

Researchers said the amount of sleep you get can also play a role. Both long and short sleep times were associated with the disorder, such as less than 6 hours and more than 9.