And this work proves what? That mental states are reflected in the brain? What a surprise!

It says nothing about how they originate. But, I think you can predict, claims to that effect will be made, by some at least, on the basis of such findings. I predict that some of those claims, which will include understanding from other approaches to mental "illness", will be of value, and some will not, leading further down a fruitless path of attribution to entirely "physical" or "biological" or "brain abnormality" origins of such distresses.