There are many kinds of depression all shoveled into the one diagnosis. It's as if malaria, flu, bacterial meningitis, and every other infection were called "ague". (They were, once.)
The only way we know to tell one from another is by what med helps, if any. If none do, it's "non-responsive depression" or some other catch-all. Depression, like schizophrenia and a host of other DSM diagnoses are the DSM's equivalents to "wastebasket taxa" in taxonomy.
People insisting that randomized controlled trials ("RCTs") prove that depression meds, and other psychiatric meds, don't work demonstrate their ignorance of the major failure mode of RCTs: unreliable diagnosis. Given that last, the RCT tells you nothing, positive or negative, absent very careful, detailed deconstruction of individual outcomes.
The only way we know to tell one from another is by what med helps, if any. If none do, it's "non-responsive depression" or some other catch-all. Depression, like schizophrenia and a host of other DSM diagnoses are the DSM's equivalents to "wastebasket taxa" in taxonomy.
People insisting that randomized controlled trials ("RCTs") prove that depression meds, and other psychiatric meds, don't work demonstrate their ignorance of the major failure mode of RCTs: unreliable diagnosis. Given that last, the RCT tells you nothing, positive or negative, absent very careful, detailed deconstruction of individual outcomes.