I'm not sure how beneficial brain scans are TBH, they're going to tell you different parts of the brain are lighting up but it doesn't give you a cause or fix. It'd be handy tracking changes in brain activity following various treatments I guess.
What intrigues me is epigenetics. It seems like modern life with its complexity and speed influence anxiety and depression manifesting in people, from the looks of it this can get passed on to children or grandchildren genetically, so there will likely be a cumulative increase in mental illness over the coming generations. Like an invisible plague.