Inside the Battle to Define Mental Illness

The authority of any doctor depends on their ability to name a patient’s
suffering. For patients to accept a diagnosis, they must believe that
doctors know—in the same way that physicists know about gravity or
biologists about mitosis—that their disease exists and that they have
it. But this kind of certainty has eluded psychiatry, and every fight
over nomenclature threatens to undermine the legitimacy of the
profession by revealing its dirty secret: that for all their confident
pronouncements, psychiatrists can’t rigorously differentiate illness
from everyday suffering...