Symptoms of PTSD often take months to become obvious. The second time around, doctors were finding twice the number of soldiers in need of help than they did after the first screening.
Though many soldiers are still reluctant to seek therapy or medication, attitudes within the Army about getting help have changed dramatically.
"When I first came to the army in 1988, I was 18 and the medical profession -- you just didn't go," said Bosely. "If you did, you were less of a soldier."
Nowadays, if a soldier has a problem, "It's not 'Hey do you want to go to the medics?' It's 'Come with me,' " he said.
Accordingly, there has also been a much broader acceptance of using a family of drugs commonly prescribed for depression, anxiety and insomnia to deal with PTSD. These medications are prescribed for soldiers who have returned home as well as those who are struggling during their tours in Iraq.
Sgt. John Newport, who says he was traumatized when he saw a young Iraqi girl crushed to death by a truck, is now taking Zoloft. "It's actually made it that I'm not so jumpy," he said.
Harriet Barton, who was wounded in a landmine explosion and then caught in an ambush, was prescribed Paxil. "I don't have those uncontrollable crying urges anymore," she said.
However, some have also learned to deal with the stress of combat in more personal ways.
Sgt. Brett Bingham, who spent a year in Iraq, keeps a journal as a way of coping with the insanity of his daily life. He says the journal allowed him to "download every single incident that happened and I could kind of forget it."
As a combat medic treating hundreds of American soldiers and Iraqis, he saw terrible things. For example, in one passage, he described seeing an enemy fighter after he had been shot.
"The left side of his skull had been blown off and all that was visible was his brain. I do not know what to do. I have seen so much blood and death. It's enough for a lifetime."
He also wrote dark poetry to calm his nerves.
As death comes like the shadows creep/ We watch children suffer as parents weep/We came to give a better life/ We leave in the midst of turmoil and strife.
Many soldiers are able to come home, struggle briefly with the adjustment, and then move on.
But thousands -- perhaps tens of thousands -- will be crippled for months or years by traumatic stress from the violence they experienced. They have left Iraq, but for some, the war goes on in their heads.
"I don't think you can go into a combat zone and return the same," said Stanley Arnold, an Army chaplain.
"The horrors of war, the ethical dilemma in being sent on behalf of your nation, to protect it. The struggle, our very nature is against killing someone else. And we have to, as soldiers, face that ethical dilemma."