Does mental illness exist?

I can't help noting an article published by The Guardian and linked at unknowncountry.com questioning, in general, whether "mental illness" is a valid clinical diagnosis. The gist of the unknowncountry commentary is that, no, there isn't really such a thing. People aren't mentally ill; they're just creatively different.

As I've opined extensively in the past, this is the 800-pound gorilla in the paranormal room: people who fit the clinical diagnosis of mental illness tend to appear on sites and talk radio shows devoted to the paranormal (and the right-wing).

My personal experience is that there IS such a thing as the classic diagnosis of mental illness, and that those who are mentally ill truly are unable to function in our consensus reality. At all. They can't communicate; they can't work; they can't perform even the most elemental tasks of self-sufficiency.

If anything, the United States lives in profound denial of the problem of mental illness. And we see the consequences daily: in our leagues of homeless, in our mass homicides, in our exploding prison population.

On a less consequential level, mental illness-denial contaminates any discussion of metaphysical topics and prevents any serious, rational investigation into what (I believe) to be valid, extraordinary experiences.  Scientists won't touch it, and I don't blame them.

The mentally ill are people who truly warrant our help, support, and treatment. Not, necessarily, our belief.

Re-re-reading for the umpteenth time..

Robert Monroe's "Far Journeys" (which I consider to be his best book).  I'm convinced: there's a there there. One thing of note, in the thirty or so years when I first read it: His description of a parallel astral area next to, and slightly out of synch with, the physical, populated with those who don't know that they're dead. This realm is vividly described in many NDE accounts... In fact, it's largely an NDE touchstone. Other authorities--notably Michael Newton, who looks at the process from the other end (regression hypnosis)--downplay the idea. I lean toward the Monroe hypothesis, largely because it makes more sense, and it explains a plethora of "paranormal" phenomena. Otherwise, his descriptions dovetail with other researchers, particularly in the various staging areas associated with death and rebirth.  I would actually like to do a textual comparison on the two accounts. I think it could be veridical (particularly since I doubt that the esteemed Dr. Newton has subjected himself to the Hemi-Sync process).