Soldiers are being denied firearms purchases due to having PTSD and or depression and police go untouched.?

As the new disabled veterans are coming back home they are getting stabbed in the back as the VA Regional Offices have adjudicated these veterans of having PTSD, depression and in some cases have been adjudicated as "incompetent for V.A. purposes" because some forget to pay their bills. Knowing the same for some law enforcement officers who have been diagnosed with PTSD or depression and so on law enforcement officers are allowed to purchase and keep their firearms vs veterans of the military. What gives with the Brady Law? Should the Brady Law be rewritten in a way that would allow even people with depression purchase and keep a firearm if the veteran does not show any threat to anyone except to the bad guys (ie people who are trying to harm us or other people or an enemy of this country) Well, I trust this makes some sense now. Can anyone provide any thoughts or refreshing ideas on this please?