The findings sounded like good news. As reported recently in The Lancet, chronic fatigue syndrome (CFS) may be successfully treated with a combination of psychotherapy and exercise. Specifically, results of a randomized trial showed that cognitive-behavioral therapy and graded exercise therapy have a moderate effect in the treatment of CFS.1
Yet a report in The New York Times2 suggested that the study results “. . . are certain to displease many patients and to intensify a fierce, long-running debate about what causes the illness and how to treat it.” The Times noted that “many patients . . . believe the syndrome may be caused by viruses related to mouse leukemia viruses, and they are clamoring for access to antiretroviral drugs. . . .” Furthermore, “. . . the new study . . . is expected to lend ammunition to those who think the disease is primarily psychological or related to stress [italics added].”2
For those of us accustomed to the charge that psychiatry is trying to “medicalize normality”—and that “psychiatry has no objective tests” to validate our disease categories—this report is both ironic and revealing. First, it suggests that patients—not just physicians—may sometimes have compelling reasons for applying the “medical model” to conditions whose etiology and pathophysiology remain controversial and obscure. Indeed, in light of the serious adverse effects associated with antiretroviral drugs, it is extraordinary that some patients would be clamoring for these agents, given the tenuous link between CFS and a viral etiology. I suspect this speaks to the profound lethargy and physical impairment experienced by some patients with severe forms of CFS—and this, in turn, speaks to an important truth regarding the nature of what we call disease. “Disease” (disease) is usually first recognized by those who suffer with it, and by their loved ones. It is not fundamentally a scientific term, but an experiential concept born of the human condition.3 Those who suffer with CFS understand this, and their predicament serves as a window into the conceptual and semantic problems that bedevil psychiatry.
Indeed, the Times report by David Tuller presents a microcosm of the linguistic ferment in the realm of medical nosology. Note that the reporter uses 3 different terms to describe CFS: illness, syndrome, and disease. This alone should tell us that in the matter of describing and classifying abnormal physical and emotional states, confusion abounds—and not just among journalists. Physicians and researchers, too, often bandy about terms such as “illness,” “syndrome,” and “disease” without much reflection as to the precise meaning of these terms, or how they differ from one another.
The Platonic enterprise of “carving Nature at its joints” is wasted surgery, if we are not relieving the suffering and incapacity of our patients.
It is notable that despite a lack of reliable biomarkers or “lab tests” for CFS, the CDC describes CFS as a “distinct disorder with specific symptoms and physical signs.”4 Here we meet yet another poorly defined term: disorder—the term of choice for conditions in the DSMs, and one that strikes some of us as a bit of a dodge. How, after all, does a disorder differ from a disease? If it is simply a matter of identifiable pathophysiology, then why is Alzheimer disease listed as a cognitive “disorder” in DSM-IV? Are we to infer that all “diseases” are also “disorders,” but that the converse is not true? It is enough to make the clinician’s eyes glaze over.
It is not merely intellectual laziness that underlies this unsavory stew of disease terms, although some-times that charge may apply. In truth, we physicians are, by and large, practical folk. We see our waiting rooms crowded with fellow human beings in various states of pain, suffering, and incapacity. We want to help them as efficiently and effectively as possible, and we don’t care very much, at the end of the day, whether we have alleviated a syndrome, an illness, a disease, or a disorder—and neither does the patient. We do care a great deal that the patient who came in feeling miserable leaves feeling better. We engage in a daily struggle to reduce the net amount of medical suffering and incapacity in the world—not to win prizes as philosophers of science or language.
Unfortunately, in recent years, some scholars and researchers have been fixated on the precise boundaries of mental “normality” and “abnormality”—as if Nature itself recognizes this neat dichotomy! To be sure, many of us—including this writer—have pointed to instances in which a condition has been prematurely or inappropriately labeled a “mental disorder.” For example, I have argued against including conditions such as “pathological bigotry” and “Internet addiction” in DSM-5, and I have raised serious questions regarding the validity of so-called hypoactive sexual desire disorder.5-7 Others have gone much further in their critique of psychiatric nosology, declaring some psychiatrists guilty of “disease-mongering” or pointing to the danger of diagnostic “fads” in psychiatry.8,9 (Recently, Dr Allen Frances directed me to an uproarious YouTube video, discussing the medical treatment of “excessive and annoying cheerfulness!”10)
Part of our preoccupation with the boundaries of normality and abnormality lies in our failure to produce “a model of mental disorder,” as Dr Niall McLaren11 recently argued. Indeed, I believe psychiatry has been hobbled by the very terms now emblazoned on our DSMs: “mental” and “disorder.” Neither of these terms has been satisfactorily defined, and neither has been very helpful. I would much rather see a classification of “neuropsychiatric disease” or “brain-mediated disease.”12 More centrally, however, I believe we have gotten lost in the “trees” of boundary issues, while failing to see the “forest” of our patients’ chief concern: the relief of their suffering and incapacity; that is, the relief of disease (disease). I believe it is from this experiential wellspring that our nosology should issue. This same reality also defines our profession’s chief ethical responsibility: namely, the relief of medically based suffering and incapacity by any safe and effective means. In short, I am arguing that our nosology must be firmly rooted in our ethical calling as physicians.
Even our diagnostic criteria should follow this ethical imperative. Thus, rather than focusing primarily on etiological validity13—achieved when a set of diagnostic criteria is based on an identifiable pathogenic agent or process—I believe we should be focusing on what I have called instrumental validity: the extent to which our diagnostic criteria enable us to reduce the patient’s particular type of suffering and incapacity.14 (Unlike Kendell and Jablensky,13 I do not draw a sharp distinction between “validity” and clinical “utility.”) We can gradually refine our prototypical disease categories, based on how well their criteria hold up in empirical studies of treatment; ie, the more the category criteria facilitate effective treatment, the higher their instrumental validity. Only secondarily should our disease categories be modified by other types of validity, such as discriminant and etiological validity (Figure).13,14 (Discriminant validity is essentially the degree to which the criteria can identify one construct, such as “narcissism,” without demonstrating a high correlation with an unrelated construct, such as “schizotypy.”15)
So, how does all this apply to CFS and the insistence by some that patients with CFS be treated with antiretroviral drugs? It would be unfair to conclude that those advocating this position are trying to “medicalize” severe, chronic fatigue, in any pejorative sense of the term “medicalize.” On the contrary: like physicians, these advocates are, in good faith, trying to alleviate disease—and they have every right to do so, regardless of how well or poorly we understand the pathophysiology of CFS. Of course, it is an empirical question as to whether antiretroviral drugs are either safe or effective in CFS. I have serious doubts, but only clinical investigation will resolve the matter. Nonetheless, there should be no quarrel over the reality of severe CFS as an instantiation of genuine disease, just as schizophrenia and major depression constitute real disease.
In my view, psychiatrists would do well to avoid scholastic disputations over “where to draw the line” between normality and abnormality.16 (If 99 in 100 stockbrokers jump out the window after the stock market crashes, is that behavior “normal” or “abnormal”?) So, too, with our nosology. The Platonic enterprise of “carving Nature at its joints” is wasted surgery, if we are not relieving the suffering and incapacity of our patients. This applies whether we are discussing major depressive symptoms following bereavement17 or severe, chronic fatigue. The central question for both our psychiatric nosology and our medical duty is just this: how much suffering and incapacity is burdening the patient who seeks our help? If the answer is, “Quite a lot,” then our patient has bona fide disease, and it is ethically incumbent on us to provide safe and effective treatment.