there is a great training program online for us (service members) on how to identify and cope with the stressors of being in combat - and then having to re-adjust to NOT being in combat.
i think your question may be better suited for a Critical Incident Stress Management (CISM) team or similar agency.
your local Police - Fire - EMS should have plans in place to react to critical incidents such as 09-11-2001 and Hurrican Katrina that can better answer your questions.
also, each state has thier own version of "FEMA" - such as in MA, we have MEMA - that can help as well.
i work closely with a lot of the "key" individuals, but can NOT divulge such information to a "regular" person w/o need to know.
You should be inquiring with your local PD, Fire or EMS about such issues... also, your local Vets Center can help as well.
There are tons of hurdles - such as privacy disclosures, discrimmination, ect . ect . - and each law has a law that can bypass, regarding the release of information.
as far as "black balling" or tagging a soldier who is being treated for PTSD goes... that should be at the discretion of the Medical Professionals, along with the soldiers family to recommend... NOT some jack ass.....
I have helped several hundred soldiers out-process from the military, who were being treated for PTSD, Depression, Adjustment Disorders who owned firearms. My org. simply made a call to the local PD who were 99% more than happy to secure the firearms while the soldier was undergoing treatment, including "in patient" treatment....
I have NOT followed up with many of them, but the ones I bump into are pretty much back to normal, and can still own and carry firearms after being cleared by a medical professional.....