He has bipolar disorder which is corrupting his brain and therefore his decisions. I think he's a good person at heart, as everyone who knew him in his younger days seems to emphasise. I don't blame him for the bad stuff because everything he does is a result of the mental illness, even when he has refused treatment (which is speculation on your part).
Unfortunately I don't think he will ever get better, but he deserves sympathy because I don't think he is happy at all, no matter what he does to fight the depression, and probably never will be