I don't think excessive sleep is beneficial...Just because I kind of did the same thing for a while...I'd sleep from 10pm until 2-3 pm the next day, mainly stress from being alone all the time in a new place while my b/f was at work, so i'd try to sleep to pass the time til he came home...But anyway, i'd find that even when I was awake I was always tired and depressed anyway, and my sleep patterns got really messed up. I don't know if it can cause sickness or anything, but it just really affected my mood more than anything. It's probably a different effect on everyone individually, but that was my experience with it. If it helps you to cope though, do it...That's better than drugs and drinking.