On average it will reverse regardless since the half-life of depression is only a few weeks, unless you take antidepressants in which case it's perhaps less severe but is also less likely to go away.
Are you referring to a single major depressive episode? And presumably not referring to the various other depressive disorders that last months to years?
FWIW, this one of many things that makes treating "depression" challenging - there are many different forms of depression, and not infrequently the underlying pathology is quite different.
Yeah if you read Anatomy of an Epidemic, Robert Whitaker has a good research review of all the large scale NIMH/NIH studies.
Why are you posting absolute nonsense here?