Well it has been said, but yeah being there for him and not judging/blaming him for how he feels is the best thing. There aren't usually words that can help too much when in deep depression which it sounds like he could be dealing with...I know from experience how much that sucks. Also never hurts to try to include them in activities or hanging out or whatever, sometimes someone in severe depression wont be up to that but it's nice feeling like at least people care enough to ask if you want to go out and do something or go hang out.