Yes, and I think that a concussion or a brain injury is often described as a sort of invisible injury. In a lot of ways, it is. In the normal way in which things are visible, we look at somebody who has suffered a concussion or a brain injury, and the standard line is that he or she looks fine. You do something to your quad, and you're limping around. The other person can see that in fact you've done something, and you know you've done something.
When you are experiencing these other symptoms of depression, anxiety, memory loss and all the rest of it, your first response is to say you're just sort of down. You've been down before and no big deal. For any of these things, you have a first explanation. Then your second explanation is to ask, "What's wrong with me?" And others are kind of doing the same thing, and then things don't happen.