Except there is a direct, causal link between treatment and life and death, or at least quality of life.

Economic or social studies are a lot more nebulous.

Seems weird to accept that "quality of life" is a straightforward measure, but insists nothing of the like can be created for social studies.

Right, and that's what this is about. They're doing the experiments. I didn't say they were too hard; I said they were hard. But it's early days of learning how to do experiments, much like medicine was not that long ago.

There's quite a bit of medicine that "works" but the specifics of why it work isn't well understood, especially in mental health. One of my friends who works in the mental health pharmacology field told me one of the challenges with the field is measuring the efficacy of those drugs. What do you do? Do you ask someone if they are feeling better or happier? Is that trust worthy? Or is it too fuzzy? Was it the drug that did it or something else? In that regard, they face similar challenges as the social sciences.