by T. Christian Miller and Daniel Zwerdling for ProPublica:

More than 2 million troops have deployed to Iraq and Afghanistan since 2001. Tens of thousands have returned with a bedeviling mix of psychological and cognitive problems. For decades, doctors have recognized that soldiers can suffer lasting wounds from the sheer terror of combat, a condition referred to today as post-traumatic stress disorder. They also have come to know that blows to the head from roadside bombs — the signature weapon in Iraq and Afghanistan — can result in mild traumatic injuries to the brain, or concussions, that can leave soldiers unable to remember, to follow orders, to think normally.

Some startling case studies–well worth reading.