if you're clinically depressed, then I highly recommend not basing your health on a depencency of pre-order games... that will only make things worse. Go play games that have been out for at least several months, and come back to this game some time after release.
We, who are better able to handle the stress, will take care of the waiting for you (as well as discovering the first batch of game breaking bugs during our initial playthroughs, so that you'll have an easier and less stressful playthrough lateron). You can thank us for that later
