Yeah, there should be direction in the application form and if there aren't or you can't find them, you need to ask someone at each program yourself. As most applications are due between 11/30 and and 1/1, you probably should have figured this out by now.
If the application information doesn't say, then it doesn't matter. I know for our program we receive personal statements that are both double spaced and single spaced, and it's fine.
