And before you point to Switzerland, I am all for gun ownership by certified, well trained, responsible citizens. But the US doesn't have that. Either decrease access to guns, or enact 2 years of compulsory military service where you are trained to respect your weapon and know precisely when and how to responsibly use it AND store it. If you do neither, you get the US.
And in either case, we need to improve the mental wellbeing of everyone in the US by giving more people access to "free" healthcare and not stigmatizing mental health.