Maybe none. But I'm not sure dismissing the suffering of other people is actually the thing that will be better for mental health.
Nobody said anything about dismissing anything, only being realistic about what you have the ability to do and how you let your attention be directed by third parties. If something is not within your sphere of influence in any way, then it is, by definition, a waste of your energy to be concerned about.
That's never true. Influence might be tiny, but it's not zero.
There's an irony, in that believing nothing can be done ensures that nothing is done.
> ...go read Wikipedia for 30 minutes and be just as caught up as anyone else because you know the end result of the news cycle instead of suffering through it as it happened.