Here is the official explanation from the film’s website http://restrepothemovie.com
RESTREPO is a feature-length documentary that chronicles the deployment of a platoon of U.S. soldiers in Afghanistan’s Korengal Valley. The movie focuses on a remote 15-man outpost, “Restrepo,” named after a platoon medic who was killed in action. It was considered one of the most dangerous postings in the U.S. military.
This is an entirely experiential film: the cameras never leave the valley; there are no interviews with generals or diplomats. The only goal is to make viewers feel as if they have just been through a 90-minute deployment. This is war, full stop. The conclusions are up to you.
While there are actual combat scenes, including wounded and dead, the viewer sees much less than he/she would see watching a fictional war movie.
There are some interviews of the soldiers returned from the deployment. One soldier in particular talks about experiencing severe PTSD symptoms. He tries not to sleep rather than sleep and relive his nightmares.
Neither he nor anyone else mentioned treatment being provided for the experiences this platoon was exposed to.