I'm not saying mental health isn't an issue in the US, but it's not like we're that much different health wise from tons of other developed countries.

20 year olds in England, Ireland, France, Belgium, Canada, South Korea, Japan, and Scotland have mental health problems. They get depressed, play violent video games, watch movies, struggle with anxiety, have suicide issues, and any other struggles an American 20 year old goes through.

So why aren't 20 year olds in those countries walking into shopping malls or movie theaters or schools at at least a similar frequency as American 20 year olds with rifles and tons of ammo and killing people?

Because they can't get one! A pissed off 20 year old living in east London can't walk down the road to his local gun store and buy an AR 15 and 100 rounds of ammo. It's literally impossible.