Yes! Even if you're looking at his character, flawed as it was, he had terrible injuries that left him in pain much of his life.

In one fairly short span, he had four concussions (from things like being near exploding mortar as a war correspondent). We know so much more about concussions now than we did in his day and the damage they can do to you. My impression from all of his symptoms is that he had undiagnosed PTSD.