I haven't seen anywhere that has confirmed Speed suffered depression, it just seems an "easy" reason for many to explain why he did what he did. But then if it does highlight depression as a serious illness anyway, then that can only be a good thing. Too many people still think along the lines of "he's got loads of money, a good job, what on earth has he got to be dpressed about?"
I think some people are jumping to conclusions, but the point is still valid - there is at least a discussion on here. If the same discussions are going on elsewhere in male-dominated areas, the irony is that this may save lives.