"Our current world mostly doesn't have effective solutions for mental health issues. "

This is not true. "Mental health issues" may be a broad field. I guess US prisons are full of such people, some beyond repair. But I know people who got hospitalized because of health issues and they are doing quite well today.

There is help. There are medications and things can normalize.

I have a friend who developed mental issues and, as far as I know, is roaming homeless in Canada. But this must not be the rule.