Looking back on my experiences, Vietnam, etc., I'll say this: the human mind is a very complex, very unique thing. They are, at least so we are told, the product of biology, nurture, experience, education, and heaven only knows what else. That said, no two of us is going to react the same way to the same experiences. My reaction to what I did and saw during my time in combat and how I dealt with it mentally, emotionally and intellectually, was mine and mine alone.
What I'm trying to say here is I don't think there is one solution to shell shock, battle fatigue or PTSD - all the same thing really.
Some of us, like me, who had a family history WWI WWII Korea, Malaya, Vietnam, of experience understood what war is and were able to use that to at least understand to some degree that what we went through was a common human event and we were not alone in what we felt, how we felt, what we thought and how we thought.
Faith in God, or perhaps faith in the righteousness of the cause gave - or gives, some comfort. But that - faith, I believe, has to be there and be strongly held long before the events to offer real benefit.
All I can say now, looking back, is that we who have been through the mill need to be there for our 'younger brothers'. We need to be there offering an ear, sharing our experience, letting them know they are not alone in all this.