Ok, that may fall under the well-studied category of autism-related "sleep disturbances". Many autistics have low levels of melatonin,...unclear why,...and respond well to a melatonin supplement before bed time. Chelated magnesium can also be taken to relax the heart, lower blood pressure, and relax the tension in the muscles. L-theanine can be taken as a means of "relaxing" the brain (glutamine blocker) and take it out of that hyperexcitable state. I take all three before bed,...if I don't,...I am up or at least "half-awake" several times a night. It's like a deep, hard sleep for 2-3 hours, then it's these "cat naps" for the rest of the night. I started that regimen above about a year or so ago,...and I feel so much better. My wife says, "If there is a fire in this house,...you're going to burn, because you won't wake up and I can't drag your butt out of bed!"