Become the Goddamn Batman

Dark Knight Shift: Why Batman Could Exist–But Not for Long: Scientific American.

There’s research suggesting that concussions might cause depression in NFL players. Could that be one reason why the Dark Knight is so brooding?
I went through a lot of comics and graphic novels and I only found a couple of examples where some of those blows to Batman’s head had the effect of something like a concussion. Whereas in reality, that would be a very likely outcome. He’s able to offset some of the physical damage to his head because of the cowl—it works a bit like a helmet. But these things would definitely add up. Since they don’t admit that he has concussions, you can’t really ascribe repeated concussions as the reason why he’s brooding.