anxiety
"I'm sixty-eight years old and have dealt with anxiety/depression my whole life.  There were some medicines over the years that helped, but for one reason or another, I had to stop taking them. But five years ago (July 17,2007) I had an acute neurological episode that awoke me from sleep straight into a Carnival Midway atmosphere. Very disturbing, and my sleep was never restful from that day forward. Four different polysomnograms verified I was getting less than a third of normal REM sleep.  Six months ago I discovered Ambien and was quite pleased, but I was recently to see a pain management doctor who understands the value of good sleep in dealing with chronic pain; his preference is Trileptal so I went on it. Never felt this relaxed and normal."