Mental health is a big subject in itself and I agree with you that the way in which we approach this subject can have far reaching effects on society etc.
My point is that gun ownership in general is not a good thing. You need a gun to kill or injure someone else but a gun makes killing easier and it’s effective.
I live in a society where guns are very restricted and the vast majority of people are not interested in owning one anyway. Neither are we paranoid about guns in general as gun use is relatively rare.
If you look at gun related deaths here — https://en.wikipedia.org/wiki/List_of_countries_by_firearm-related_death_rate (I cannot vouch for the accuracy) and order by death rate total you’ll see the USA is right up there but the rate is quite low for Australia. This correlates to a point with this list of gun ownership — https://en.wikipedia.org/wiki/Estimated_number_of_guns_per_capita_by_country. For the UK the gun death figure is tiny. All this seems pretty obvious to me, lots of guns means lots of deaths by gun and vice versa. Very few people actually need a gun but we do need knives, ergo gun restriction is an easy benefit win!