As harsh as it sounds, why should the lives of 400 people (and that's with weak correlation) who suicide matter more than the life of 10 million in near-poverty?
I'm sure that if you had a referendum, people would opt for "more income" rather than "more mental help"
Surely you should choose the option which aims to better the lives of the many, not the few, and benefiting the 10 million by fixing the economy also benefits the potential suicides, because that's what this "correlation" points to.