Other side effects I experienced were clearly under-reported by the pharmaceutical companies. E.g., negative sexual side effects for Prozac that my doctor wouldn't even believe were real and not psychosomatic, until it later turned out that 25%-50% of all patients suffered these side effects, and the pharmaceutical company had neglected to inform anyone.
On other other hand, Remeron surely saved my life. I have no doubt about this. I had been in the most miserable state you could ever possibly imagine and then some, and had been this way for months, and then within a day or two of starting Remeron, I was utterly fine. (Though ironically, it may have been another antidepressant that put me in this terrible state to begin with, as I had to go off it cold turkey due to it causing a different dangerous side effect.)
As for diagnosing depression, it may certainly be the case that many cases are difficult to diagnose correctly. And there may be cases where there is no fact of the matter as to whether the particular symptoms count as depression. On the other hand, there are certainly cases where there is no question at all as to whether it's depression. I have been there quite a few times, and it's been as cut and dried as anything can be in this world.