So perhaps those who are truly clinically depressed

You're making an elementary mistake. The definition of clinical depression is not based on evidence, but consensus opinion. It is whatever it is defined to be. Anyone who is said to be in the state 'truly' is in that state.

There is instead an overwhelming preponderance of evidence that most psychiatric concepts are distinctions without differences. That is inconvenient for most, and correspondingly ignored - or left to ignorance.