Source: American Psychiatric Association

Fellow PT blogger Stephen Diamond supports the inclusion of bitterness in the next edition of the (DSM-V). Indeed, he believes "emphatically" that bitterness should be recognized as a stand-alone disorder.

But Dr. Diamond doesn't stop there. In his reply to my post, which voiced concern about diagnostic overreach (something Peter Kramer once called "diagnostic bracket creep"), Dr. Diamond writes that "Rage Disorder" and "Hostile " should also be considered for inclusion in the world's diagnostic bible of mental disorders. As Dr. Diamond puts it, bitterness is "just the tip of the proverbial iceberg."

If bitterness is to become a mental illness, why not just go the whole hog and, as Dr. Diamond recommends, create new disorders for "the pre-eminent role , rage, resentment, hostility and bitterness play in the etiology and perpetuation of so many different mental disorders, and in human suffering and destructiveness in general"?

What surprised me, given this almost encyclopedic list of common emotions, is that Dr. Diamond voices no concern about the risks of misidentifying the threshold between justifiable and chronic bitterness, anger, rage, and so on. He seems to know exactly where the cut-off lies. He also appears to believe that all of his colleagues will agree with him and put the line exactly where he does. There are no stated qualms in his post about (a) diagnostic overkill/redundancy or (b) diagnostic uncertainty/ambiguity regarding the line between acceptable and unacceptable bitterness, anger, and so on. And that, to my mind, is "just the tip of the proverbial iceberg" in terms of serious, legitimate concern about where this could lead us.

First, concerning point (a) above, DSM-IV-TR already lists , Disorder, , , , and countless more poorly defined and controversial diagnostic labels, all in large part oriented at defining as mentally ill the kinds of behavior that Dr. Diamond wants to pathologize further. But no psychiatrist intent on listing yet more disorders in the DSM should be blind to the risks of overdiagnosis, given the embarrassing amount of overlap that already exists among these disorders. The problem concerns not only overkill but also redundancy and thus professional imprecision—something the world's diagnostic bible can ill-afford, given the millions of lives it diagnoses.

Second, there's an alarming, and alas common, sleight of hand in Dr. Diamond's post between advocating for the inclusion of a disorder on the basis that it will lead to further research (his recommendation) and acknowledging that inclusion itself, with the provision of a diagnostic code, specifies a mental illness and thus gives clinicians a green light to prescribe and other forms of treatment, such as or . It's simply disingenuous to fudge that key issue. If behavior deserves to be studied, then it can and should be, independently of the DSM. That's not a viable rationale for listing a putative disorder as a bona fide one—not in such an important manual.

Third, while Dr. Diamond displays emphatic certainty in representing bitterness, rage, anger, and more as stand-alone mental disorders, a simple glance at history and other cultures indicates that we're pathologizing what earlier cultures and generations took to be acceptable, even honorable and vitally necessary traits and behavior.

At least until the late-nineteenth century, for instance, misanthropy (hatred of humanity) was prized as a key component of human behavior. From the ancient Greeks to the mid-Victorians, misanthropy signaled scorn for vice, corruption, and stupidity. From Seneca to Molière, Shakespeare to Dickens, and Byron to Thackeray, misanthropes have played a major role in sharpening critique, insisting on reform, and demanding alternatives to the status quo. Today, by contrast, misanthropy is itself scorned as a pathology. In most forms of academic , it represents a condition bordering on derangement, even lunacy. All of the leading psychiatrists that I interviewed in my book Shyness: How Normal Behavior Became a Sickness said that it was justifiable grounds for medication.

What's wrong with this picture? Time and again, in researching the thresholds set for mental disorders, one finds that distinctions psychiatrists believe are not only firm but also black and white are in fact mobile and full of shades of grey. If truly ruled out shyness, for instance, as the DSM now advises (having for years listed numerous symptoms that overlap with shyness, such as public-speaking ), then the prevalence rates, most agree, would be closer to 1%-2% of the population. That's because diagnosis would be limited to truly chronic, impairing behavior. One would no longer see the absurd claim, oft-repeated, that one-in-five Americans suffers from disorder. That figure in fact stemmed from a single article—a study resulting from random phone interviews with 526 urban Canadians, based on questions such as whether the participants were afraid of going to parties and disliked figures of authority.

Discussion of Apathy Disorder also has been shockingly imprecise in blurring (a) apathy as an effect of medical conditions such as Parkinson's; (b) apathy as a side effect of SSRI medication; and (c) apathy as a colloquial judgment regarding those who are disinclined to work. It simply beggars belief that reputable psychiatrists would recommend inclusion of the term as a mental disorder after confusing those three issues, but they did. Point (a) would of course rule out listing the disorder in the DSM in the first place. Disinclination to work, point (c), of course doesn't constitute a mental disorder, though amazingly these days that doesn't go without saying. The logical consequence of (b), meanwhile, would be to cut back on medication-inducing side effects. But psychiatrists wanted to pathologize these side effects, to render them proof that the person suffering from them was mentally ill in ways hitherto unimagined!

Instead of recognizing the folly, hubris, and serious consequences of such diagnostic overreach, psychiatrists wanting to pack yet more disorders into the DSM claim they are doing us all a favor by representing underreported and underdiagnosed issues. But they're actually muddying the waters and creating untold confusion over normal and pathological behavior, based on provisional judgments and distinctions that subsequent research teams, drug companies, and billions of dollars of direct-to-consumer hype, exaggerate, and distort.

I think that if such psychiatrists truly thought about what they're doing, they'd close their DSM and open their Seneca or Molière, to reflect a fraction on how earlier writers and thinkers represented behavior that psychiatrists today take to be signs of mental illness. Part of what's missing from the discussion, in short, is the insight that comes from historical perspective and understanding.

Christopher Lane, the Pearce Miller Research Professor at Northwestern University, is the author most recently of Shyness: How Normal Behavior Became a Sickness. Follow him on Twitter @christophlane