From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958868/ here.
This is a specific type of parasomnia, per the recent American medical classification. This occurs during NREM (non-rapid eye movement) sleep, usually the first stage of sleep, and specifically Stage III-IV of NREM. Your friend's case is somewhat unusual. The part where he drives is dangerous, so I think it would behoove him to see a specialist, if you care to inform him. |
I am a retired psychiatrist, and I take an interest in such things because it runs in my family. My father sleepwalked and also sleep-ate. He went across the house to the kitchen, removed ingredients from the refrigerator, ate the sandwich, and then came to the middle of the house, where he fell asleep on the sofa. We only knew he ate because he left a jar of mustard out with the lid off all the time. We already knew he sleepwalked, since he ended up on the sofa, but since we had a one-story house, there was no danger. I had sleep terrors as a young child, I walked in my sleep, and danced in my, sleep, which are all parasomnias of NREM sleep. I have sleep walked a few times as an adult, once down a very long marble stair case, so I do not sleep upstairs any more. My brother sleep walks also.
We have never needed any treatment, but your friend's driving sounds dangerous, and there are treatments. I hope this helps and is within guidelines.