Just for a little historical perspective: The Parker v. Washington DC case was the case that eventually morphed into Heller and subsequently the SCOTUS case affirming an individual right to own a gun regardless of one's militia "status." Parker had several plaintiffs, all except Heller were found to NOT have standing and "their" cases were thrown out and Heller emerged as the only one with standing. One of the original plaintiffs was Tom Palmer, a gay man that alleges that he used a 9mm handgun to defend himself against a "gay bashing" incident. He states that he produced his gun (that was, incidentally, carried illegally...) when a group of men who had been verbally harassing him threatened physical harm. He did not have to fire a shot as the men dispersed, rather quickly, once he drew his handgun.
The point is that any person, regardless of race, color, creed, political affiliation, or sexual orientation, should be allowed to determine what, if any self-defense tool he wishes to use irrespective of the statistical possibility that they "might" have a psychiatric condition. And that distancing ourselves from potential allies because of that potential could be counter productive. After all, soldiers (airmen, sailors, and marines) returning from deployment have a much higher rate of suicide and PTSD. Are we trying to distance ourselves from them or are we trying to get them the help they need while preserving their god given rights and liberties as we try to do the same for ourselves?