Mental illness is spiritual, so is any other kind of illness. By spiritual, I mean it has roots beyond what can be physically observed. If humans are spirit beings (the core of a human being cannot be seen or touched — I say that and every word here as a layman of course, not a physician), does it not follow that everything is spiritual? That of course does not mean “not physical”. Everything in human experience that has a physical appearance also has a spiritual origin, no? The good thing about physical manifestation is that it allows physical interventions. We can physically intervene in mental health cases as in other kinds of illnesses because all illnesses have a physical aspect that can be “played” with. But because they are spiritual, we can spiritually intervene too. The problem is not that spiritual interventions do not work but that we are largely clueless about how they work so people sometimes kill themselves and family members due to ignorance and intellectual dishonesty masquerading as faith. The wise thing to do when one is ill therefore is to go for interventions that you know well not what you are unsure of but as you said, religious leaders will need to help in educating their followers that doctors and medication are life savers. I believe though that as knowledge advances, faith and science will meet. The fact that they are yet to meet is because in my opinion, both faith and science are still not as developed as they could.