Editors’ note: Ronald Pies is a Clinical Professor of Psychiatry at Tufts University. We are pleased to publish his letter below.
I have followed the exchanges on psychiatric classification at Cato Unbound with great interest, as this is an area of study that has occupied me for over thirty years. In his remarks on the nature of “disease,” Prof. Jeffrey Schaler makes claims regarding pathology textbooks that are, at best, simplistic and misleading; at worst, they are transparent falsehoods that have been repeated without foundation for many years. Indeed, I brought this to Prof. Schaler’s attention several years ago when I sent him my paper on schizophrenia and how this illness is represented in various non-psychiatric medical texts. Prof. Schaler claims that “Pathologists do not include mental illness in standard textbooks on pathology” and that “Mental illness is not included in standard textbooks on pathology because it refers to behavior, not cellular pathology.”
One of Prof. Schaler’s premises seems to be that the only valid medical texts on “disease” are pathology texts. Most physicians would dispute this. Prof. Schaler omits discussion, for example, of numerous books on general medicine or internal medicine that recognize the reality of conditions like schizophrenia and bipolar disorder and discuss them at length. Furthermore, many pathology texts omit references to, for example, migraine headache. This is widely recognized as a neurological disorder, even though its “cellular pathology” is poorly understood.
Let’s begin with Boyd’s Introduction to the Study of Disease, Eleventh Edition, published in 1992. The author, Dr. Huntington Sheldon, was at the time a professor of pathology at McGill University. Dr. Sheldon classifies schizophrenia under the rubric of “functional disorders.” He goes on to argue that schizophrenia “…might be regarded as a cancer of the mind, gnawing into the very soul of the patient.” Now, those who believe that schizophrenia is only a “metaphorical” disease may dismiss Sheldon’s vivid description as mere poetic imagery—not the stuff of hard science. Yet Sheldon goes on to note the beneficial effects of hemodialysis in “a small group of schizophrenics,” leading him to hypothesize that there may be “a biochemical substance… that directly affects the ordered functioning of the central nervous system” in schizophrenia. Clearly, for this pathologist, schizophrenia is no mere “metaphorical” illness.
Almost a decade after Dr. Sheldon wrote this, we find another discussion of schizophrenia in the textbook Biology of Disease, Second Edition, by Phillips, Murray, and Kirk. Although this is arguably not a “standard” textbook on pathology (it also encompasses elements of clinical medicine), Dr. Murray was then in the department of pathology at the University of Birmingham, United Kingdom. All told, there are seven pages in the text that deal with schizophrenia. Schizophrenia is considered in detail in the chapter entitled “Psychological and social aspects of disease.” Phillips et al., observe that “A variety of clinical investigations and imaging techniques… have revealed a number of interesting findings [in schizophrenia], including evidence of cerebral atrophy, left temporal lobe dysfunction, [and] evidence of neuronal loss and disorganization.”
The Phillips et al text goes on to note that the significance of the “inconsistent” pathological findings in schizophrenia are “a matter of current speculation,” however there follows a critically important statement: “the biology of this disease is as yet poorly understood.” [emphasis added]
Now, critics of psychiatric diagnosis may rush to seize upon the words “poorly understood”—but that would be a serious philosophical error. The biology of many diseases, including some types of cancer, is “poorly understood.” The critical words are “this disease.” There is simply no question that the authors of the text view schizophrenia as a disease—and that this classification is not dependent on our having a full understanding of schizophrenia’s biology.
As Dr. Allen Frances points out, schizophrenia is probably a final common pathway for many different pathophysiological processes; my point here is that psychiatrists are far from alone in using the term “disease” in reference to schizophrenia. Other references to schizophrenia may be found in standard pathology texts, such as the Oxford Textbook of Pathology. But the coup de grace for the claim that pathology texts don’t recognize schizophrenia is delivered by the 1997 textbook The Neuropathology of Dementia, edited by Esiri and Morris, in which 20 pages of text discuss the neuropathology of schizophrenia. Moreover, since that text’s publication, hundreds of controlled studies of the neuropathology of schizophrenia have appeared in peer-reviewed journals and are converging on several consistent biological abnormalities. References to these will be made available on request.
Prof. Schaler and others may continue to ignore these patently non-metaphorical references to schizophrenia, just as they ignore the intense suffering and incapacity of those diagnosed with schizophrenia and other instantiations of disease (dis-ease). But a priori arguments and linguistic analyses of supposed “metaphors” reveal the intentional properties of language, not the psychological and neurological properties of human beings. Facts about language are not facts about human illnesses. To assert otherwise is to commit a form of what philosophers call “the intentional fallacy.” The facts of human suffering will continue to assert themselves quite stubbornly, and physicians of several medical specialties will continue to recognize and treat the painful reality of psychiatric illness.
Ronald Pies, MD
Professor of Psychiatry, Lecturer on Bioethics & Humanities,
SUNY Upstate Medical University, Syracuse, New York
Clinical Professor of Psychiatry
Tufts University School of Medicine, Boston, Massachusetts
 Pies, R. “Psychiatric Diagnosis and the Pathologist’s View of Schizophrenia” Psychiatry (Edgmont). 2008 Jul;5(7):62-5.
 Sheldon H. Boyd’s Introduction to the Study of Disease, Eleventh Edition. Philadelphia, PA: Lea & Febiger, 1992.
 Phillips J. In: Biology of Disease, Second Edition. Murray PG, Kirk P, editors. Hoboken, NJ: Wiley-Blackwell, 2001.
 Talmud PJ, Humphries S. “Molecular genetic analysis of coronary artery disease.” In McGee JO, Isaacson PG, Wright NA, Dick HM, editors. Oxford Textbook of Pathology Volume 1: Principles of Pathology. Oxford Medical Publications, 1992.
 Esri MM, Morris JH, editors. The Neuropathology of Dementia. Cambridge: Cambridge University Press, 1997.
 Pies R. “On Myths and Countermyths: More on Szaszian Fallacies.” Arch Gen Psychiatry. 1979 Feb;36(2):139-44.