That's why I suggested a SSI disability payment hurdle. See a psychiatrist at the VA or privately -- no problem. But if someone is so impaired that he can't work, and needs to collect disability payments, I can see that there could be a problem. It's a much higher bar than just seeing a psychiatrist and taking an antidepressant.
I think politicians and gov't employees must be lazy, stupid or lazy and stupid. There are ways to prevent people who shouldn't buy firearms from buying firearms, while not preventing any people who shouldn't be prevented from buying firearms. In many of these cases it looks like the victims as taxpayers were paying for the guns and the ammo that was used to murder them.
Of course I would suggest there would need to be a system with an appeals process. If someone's psychiatrist is willing to certify that a SSI recipient is so impaired that he needs to collect disability payments, but still presents no danger to himself or anyone else, fine. Take him off the prohibited list, or don't put him on the list in the first place.
The SSI hurdle should just apply to mental/emotional/psychiatric disability.
People with physical disabilities would have a greater need for a handgun for self-protection than non-disabled people.