The LA Review of Books, reviewing Hubert Dreyfus and Sean Kelly’s All Things Shining:
It may seem strange for a book about the good life to make such an extended example of Wallace, given that he was famously depressive and hanged himself.
No! David Foster Wallace was not famously depressive. Lots of people who read him very, very thoroughly, including me, didn’t know he suffered from depression until after his death. His depression is only intermittently present in his writing and never governs it. To read his books as a warm-up to his suicide is to waste them.
Quomodocumque 
This is arguing over semantics, really, but still: he wasn’t famously depressive in life, it’s true, but it may be true to describe him as such posthumously. For another example, off the top of my: Not many people outside his friends and family knew about Mozart’s vulgar side when he was alive, but 200-odd years on, he could fairly be called “famously scatological.”
When one who is depressive reads DFW, the clarity of the disease is powerful. Depressives don’t necessarily lack humor, but they do have other ways of looking at the world that are certainly unique.
You’re absolutely right, but harrison above also has a point that leaves Arne De Boever an out. He could reply much as Updike did to Roth.