I had a sleep study for apnea before I was aware/dx with ASD. So I can't answer that question. But they also look for things like sleep paralysis, and something about excessive sleepiness during the day (they made me take naps the next day). They also found out I clench my teeth at night which the dentist hadn't yet picked up on.
It was really good for me.
_________________
"Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind."