Fucking hell man. There was help available if you were feeling down.
I'm pretty sure his mental issues went a lot deeper than just "feeling down"... that's probably the case for most, if not all, suicides too. Unfortunately mankind sucks at dealing with mental health, maybe because it only recently became a widespread issue, and this kind of thing is just happening more and more. I almost get the feeling that all of us know someone with these struggles, that most of us will see a close friend or relative commit suicide at some point, and... what can we do, really? I don't know how these things can be dealt with. It sucks.