lol @ people thinking they understand other people, or can somehow relate to these things. Seriously, it's pointless. My sister is bi-polar, manic. Best friend of twenty years is manic, manic-depressive. They are not normal people. I've been through depression, but I'm certainly not bi-polar, nor am I manic/manic-depressive. Their depression comes and goes like the wind. One minute they're perfectly normal people, the next they're telling you you're a shit-bag loser for no reason other than you've been sitting on their couch for one too many minutes (or whatever reasoning their mind came up with at the time). My friend acts in a way very similar to Robin Williams. Generally a hyperactive funny guy.
Don't pretend like you know what they're going through, it's honestly insulting. Similarly, I won't ever pretend like I know what anyone else is going through. The best thing I could ever do for either of them (my sister and friend), is to be as normal, stable as I can around them. Even when their windfury proc's and they rage at me for no reason. They appreciate that more than everyone else who try to diagnose or "treat" them. You're not a fucking doctor and they didn't ask for your fucking help.