I actually have the answer to your original question. I must have missed it then. We do know that people who deploy come home with higher levels of mental illness. We know that.
Again, it gets back to the original couple of comments. It's not so much the deployment; it's what happens to you on deployment that makes a difference in terms of risk for mental illness.
Mostly it was people working under the army command who were exposed to these more psychologically traumatizing events, but we certainly did have a few people from the navy and the air force who were exposed to similar things as well.