I think the fuzziness is a problem to assess treatment, and such a test would help sort different clinical realities behind that admittedly vague behavioural cl

I think the fuzziness is a problem to assess treatment, and such a test would help sort different clinical realities behind that admittedly vague behavioural claim. Right now, the choice between the several treatment options (diet, exercice, talk-therapy, drugs; electro-choc and neurosurgery for the worst cases) are given based on more patient's consent than on scientific distinction between the possible issue with the underlying mechanism. It is great to give patient that choice: agency certainly helps for early on-sets. However, it's not enough. Depression is the result of factors: live events, recreational drug use, bad habits, genetic conditions -- but just considering those is still too vague. Having biological tests (imaging, blood samples, genetic) would help a classification that could be a great help. It certainly was with cancer, a single word that covers entirely different diseases.