As a vet who brought back his own issues from The Big Sandy BOHICA, I think this article is false and misleading. You can't cure PTSD in six weeks. Playing FPSs sounds like a sure fire way to REIGNITE my inner demons, not cure them. I had to literally turn off my PS3 in the Vietnam portion of BlOps, because it disturbed me too much.
In other words, this type of mental state cannot be cured by witnessing more violence. Also, it takes YEARS to get "around" it. You never "get over" what you bring back, you never forget. You're only able to better cope with it, to better control the anger or sadness.
This article actually makes me kinda upset, because it references NOTHING that can be disproved. Pvt. Hawker sounds like a name randomly picked from any recent space marine video game, and they use generalizations, "a number of veterans", or "to a certain degree, it's working".
Believe 50% of what you see, and none of what you read.