I don't disagree, but reflecting solely on your comment, I wonder if we should try and capture/record such disorder as a preliminary step to coming up with better ways to tackle it?

It probably loops back to better mental health care provision? But might also relate to provision of social housing? Or any number of things. These sorts of indicators can feed into a 'gross happiness quotient' to help us focus on improving society for all of us, not just feeding the greed of the billionaires which a lot of Western society seems to be subservient to right now.

But why is there a need to measure it in the first place and then only react to it?

You already came to the proper conclusion by just thinking about it for a few minutes. Let's just skip building out a surveillance state, and put that money directly into mental health & housing initiatives instead.