I think that when we are attacking mental health issues, we need to think of it like the swiss cheese model of security in IT, except that we are on offense instead of defense.
Everything needs to be on the table. Mental health affects how it feels to exist, which is pretty damn important when it comes to quality of life and finding some fulfillment, comfort, happiness, etc.
There is usually not a single thing that "cures" somebody. And if there is such a single thing that works so wonderfully, it certainly does not work that well for the vast majority of people.
