The question to answer is, should individuals with mental illness be allowed to own guns? The hole gets deeper when you then have to answer which ones (or is it all, no matter how “small”), what level of diagnosis/“proof” is required, can somebody be “rehabbed” and subsequently go back to owning guns, etc.
Logically I don’t want a mentally deranged individual to have a weapon, but the harder determination is how does that desire sync up with 2A? Is a PTSD claim considered mental illness? This is a tough one.