Even if we could Properly treat Mental Health, where's the line as far as use of/access to one's Records of that treatment...
and beyond that sometimes the difference between 'Functioning' and 'Dysfunctional' is a person's dose of medication or the stress of their life...
I can be a perfectly wonderful happy person on Tuesday when my doctor signs off on my 2019 Drug script, and apply for a Gun on Wednesday, I'm Legally armed before Thanksgiving...
if I get drunk on New Years and that champagne interacts with my Meds in such a way that I 'break' immediately, or decide I'm smart enough to not need the pills any more... Come Valentine's Day and my Girl decides she's had enough of 'un-medicated me' bad things have the potential to happen... but as long as I've picked up my next 90 days worth of Pills there's still no paper trail to show i'm crazy (again)
Yes Mental Health needs to be stepped up, but making it a factor on Every Gun purchase will do more to erode medical Privacy than it will stop 'gun crime'