ClydeFrog, if you were addressing me, I think you missed my point entirely.
My point was that if we use "mental health" as a potential barrier, then we have to stay very much on top of what conditions will be counted, and how determinations will be made, and we need to ensure limits and checks are in place.
Allowing vague wording in any such restrictions would allow for political abuses by government, and advancement of personal agendas by bureaucrats and psychological personnel.
Lots of things sound reasonable at first, but then have nasty and unanticipated effects. For instance, when Lautenberg was passed, did any of us suspect that getting into a fight with one's brother would count as "domestic violence"?