Originally Posted by MSD

I used to have it at least two or three times a week. I'd be falling asleep, then wake up and hear what sounded like static or low mumbling in a crowded room. My eyes would close and my breathing would get shallow, with resisting it being very difficult, and a few seconds later I would have a serious adrenaline rush, feel like I was flying at a very high speed for a few seconds, and jolt wide awake feeling like hot needles were poking me all over. The adrenaline rush would pass and I would either fall asleep or it would happen again.

I sometimes had it happen ten or more times in a row. It got to the point that it was an enjoyable rush rather than something scary. I have nothing scientific whatsoever to back this up, but I suspect that the adrenaline rush and loss of control were a psychosomatic condition to stimulate dopamine production and compensate for low levels.