Just read this post in Comics Must Be Good about the fabled Mickey Mouse strips where he tries to kill himself:
Yeesh! And of course that brought to mind a recent Popeye strip where Olive Oyl tries to do exactly the same thing...
And then I thought about this really creepy-ass series of Garfield strips where he apparently falls into some slip in time or whatever where he's really dead or does not exist:
But then, of course, there is the most depressing, disturbing comic strip of them all: