Something to do with diabetes or the injury from Nam, I don't know.
About nine or ten years ago, I found it getting impossible to shut down and go to sleep. VA Dr said they didn't have anything. Went to an outside Dr and he prescribed Ambien CR. Works well but lingers much of the next day. VA gave me a smaller dose of cheap no CR Ambien that works somewhat. I don't sleep well but feel like I need to all the next day sometimes. Of course the other medicines complicate things.
It is partially responsible for weight gain. Don't thin I've sleep walked though.