Yes the Army does prescribe Anti depressants for PTSD. I had a friend go through this in Afghanistan. Was an NCO, stepped on a pressure plate that fatally wounded 2 others and he was messed up. First thing they do is prescribe anti-depressants. by the way - this was his 3rd deployment. 1 to Iraq and 2nd time in Afghanistan.
If he was in the hospital being treated with them that's one thing. If he was with his unit taking them that should be stopped. There is the very real possibility of an adverse reaction called Serotonin Syndrome. Serotonin is a chemical of which 98% is in the stomach for digestion. Antidepressants can cause it to migrate to the brain. When this happens it is like LSD in the havoc it creates in the mind.
This is not Junk Science it is proves long time known medical fact. Also a person lets saw taking Zoloft develops a sinus allergy or head cold and takes something like Nyquil with an antidepressant that too can trigger it.