I can't comment much on the issue of depression. I have very little experience with it, so anything I would say would be sophomoric and throw away. Many others have shared their thoughts on depression, and there are lots of helpful and sympathetic words floating around that speak to that angle on this. His death was shocking (as almost any early death is), but not surprising at the same time.
What I can comment on is my reaction to him as an audience member and as one who observed some of his work. His finest films, to me, were his dramatic ones. "Awakenings" is a wonderful film, and his performance in it (as an introverted, left-brained research doctor who ends up aiding patients with a nervous system disorder) is heartfelt and true. "Good Will Hunting" is hardly a unique work, but it feels like it is, partly because of his presence in it. "Good Morning Viet Nam" is great not only because one sees his comic largesse, but also because it is a story rooted in the tragic realities of war and his character's reaction to that.
Where he always truly shined, to me, was in talk show interviews, particularly when he visited Johnny Carson. It was only there that the confines not only of the medium but also of the host could be truly obliterated by his comic genius. The reason he was at his best with Carson is that Johnny was the best host at truly being a spectator along with the rest of us. When Jonathan Winters died last year, I watched the clip of him and Robin Williams together on Carson several times. My wife truly got sick of it.
There was a searching for God in his humor as well. Whether he mocked religion or merely toyed with some of its implications, it always seemed like he had a mind that was partly focused on the spiritual.
As my own little tribute, I will share that clip of him and Winters which aired in 1991...
