I really try to downplay the depression-based suicide angle - at least for my own sanity. I like to think that large part of depression is based on circumstances, I leave out the clinical cases that have underlying physiological causes. If you are unhappy enough to end your life, then there are probably things that you can change to stop feeling that way, i.e. job, relationships, friends, habits.

In a lot of ways this make sense to me, he was probably under a lot of pressure to be the guy that everyone really liked. Created this unrealistic expectation that was stressful to meet. Add in poor habits, maybe strained relationship and friends to lean on. It's not hard for people to feel like there is not point in going on with life.

EDIT: I am open to being wrong and invite a discussion of others opinions.