Diagnostic criteria are not the same as the disorders they identify.
Chinnapong/AdobeStock
This article is a response to the article “Descriptive Labels Are Not Causes, No Matter How Hard You Try: A Response to Pies and Ruffalo” by Jani Kajanoja, MD, PhD, and Jussi Valtonen, PhD.
We thank Jani Kajanoja, MD, PhD, and Jussi Valtonen, PhD, for their thoughtful and vigorous rejoinder to our article. While we have many disagreements with their thesis, we know that our Finnish colleagues share with us the wish to provide the best possible care for our patients. We now wish to respond to some of the salient claims and conclusions in their rejoinder, with the caveat that we are providing a severely abbreviated and selective response. We hope that, in due course, we will be able to address their arguments more comprehensively.
We believe that at the heart of this debate are at least the following questions: (1) What is meant by the term diagnosis in psychiatry? (2) How do diagnostic criteria (as in DSM-5) relate to clinical conditions? (3) What is the nature of causality in psychiatry? (4) What causal weight and explanatory power does a psychiatric diagnosis carry? (5) What constitutes circularity or tautological reasoning in the way psychiatric diagnoses are formulated?
First, however, we would like to clear up a few confusions and misapprehensions arising from our article. Our volcano analogy has been misunderstood by several readers, including Drs Kajanoja and Valtonen (henceforth, Drs K & V). In truth, the vignette could have been presented more clearly. As most readers will recall, analogies are formally stated as “A is to B as C is to D.” In our volcano vignette, the corresponding terms would be: (A) visible, surface manifestations of a volcano are to (B) the deep structure of volcanos (underground movement of tectonic plates) as (C) clinical manifestations of psychiatric illness (hallucinations, delusions, etc) are to (D) the etiopathology/pathophysiology of the illness.
Our aim was primarily to show that we do not need to know the deep structure (ie, etiology) of some event, condition, or phenomenon—whether volcano or schizophrenia—to assert that the entity has causal efficacy, (ie, that it can make things happen). We were assuredly not analogizing or likening a psychiatric diagnosis or disorder to a volcanic eruption—though, quite frankly, any clinician who has witnessed a severe, uncontrolled manic episode might beg to differ!
In any case, the analogy is not crucial to our central argument, which is essentially this: diagnostic criteria such as those in DSM-5 must not be confused with the clinical condition to which the criteria point. We believe that this confusion permeates nearly all the arguments put forth by Drs K and V, and leads them to draw erroneous conclusions regarding the causal weight and explanatory power of a psychiatric diagnosis.
The diagnostic criteria for a given DSM disorder/disease are indeed descriptive—nobody disputes this—but they are not merely descriptive, as Drs K and V seem to believe. The diagnostic criteria are also indicial, defined as “of, pertaining to, or resembling…an index finger.”1 The diagnostic criteria point to something external to themselves; namely, to an actual clinical state of affairs or condition embodied in the patient.
It is trivially obvious that it is not the diagnostic criteria that cause the patient’s symptoms—and, of course, nobody in clinical psychiatry would claim that. The criteria are merely inert words in a manual, or concepts in the heads of DSM committee members. Rather, it is the clinical condition to which the diagnostic criteria point that causes the patient’s symptoms. As our colleague, Awais Aftab, MD, has put it in his elegant deconstruction of the issue (in which he specifically critiques the paper by Drs K and V)2:
“The diagnostic criteria in official manuals such as the DSM and ICD are simply indices, as a way of pointing towards and recognizing the existence of a state, a condition, a syndrome, a property cluster, etc. They do not constitute the condition itself (see Kendler 2017). It is not the case that “depression” is nothing more than the symptom criteria in diagnostic manuals. Rather, the criteria are a way for us to recognize the condition of depression.”
In more poetic terms, as a Buddhist saying puts it, “A finger pointing at the moon is not the moon.” We believe that Drs K and V repeatedly confuse the indicial function of DSM diagnostic categories with the conditions to which they point. To borrow 2 terms from the linguist Ferdinand de Saussure, they confuse the signifier with that which is signified.3
Psychiatric Diagnosis Requires More Than Symptom Lists
The following is an example of how we see things quite differently from Drs K and V. Our 2 colleagues present the following statement: “Alex is experiencing depressed mood, loss of pleasure, insomnia, weight gain, and psychomotor agitation.”
Drs K and V present this as a kind of prototype of psychiatric diagnoses, which they define as, “…labels for situations in which given diagnostic criteria are met.” They contrast the above statement with what they call a “causal claim,” such as “Alex is experiencing depressed mood because their partner wants a divorce.”
With all due respect to our Finnish colleagues, we think they have grossly oversimplified—indeed, trivialized—the diagnostic process in psychiatry. To put it bluntly: anybody with keen eyes and ears, and 15 minutes to spare, could easily determine that a friend or family member has depressed mood, loss of pleasure, weight gain, and visible agitation. That is not diagnosis! And it is a far cry from diagnosing, say, the depressed phase of bipolar I disorder, which requires a holistic synthesis of the patient’s developmental history; course of illness; relevant medical history; family history; pertinent medical rule-outs; mental status exam, etc.
Once again, in our view, Drs K and V seem confused about the difference between raw diagnostic criteria and the actual clinical conditions to which the criteria point. A psychiatric disorder is a gestalt, and is2:
“…not identical to a mere itinerary of parts in isolation. This is because a whole also includes the interactions and relationships between parts that often generate novel properties.”
Moreover, “An accurate descriptive diagnosis connects an individual person in the clinic with a large body of clinical and scientific information.”2 This includes validators such as “…genetics, family history, personality traits, risk factors, course of illness, [and] treatment response.”2 These supportive data are almost never captured in the formal diagnostic criteria.
In sum: Drs K and V minimize or entirely negate the causal weight that inheres in a diagnosis of at least some of the most serious psychiatric disorders, such as bipolar I disorder, schizophrenia, obsessive-compulsive disorder, and others. (To be sure: not all psychiatric diagnoses possess this degree of causal weight or number of validators—a topic for another time).
Regarding Circularity and Causal Weight
In fairness to Drs K and V, they have now clarified that they did not claim that:
“…psychiatric diagnoses, in and of themselves, reflect circular reasoning…There is nothing wrong with descriptive diagnoses as long as their descriptive nature is made clear. Our criticism was directed towards falsely invoking a psychiatric diagnosis as an explanation for the symptoms, which is a logical fallacy.”
We appreciate the clarification, but we do not agree that psychiatric diagnoses have no explanatory power or content at all, as Drs K and V imply. Furthermore, we find no basis in logic—or in clinical realities—that would show descriptive and explanatory to be mutually exclusive or disjunctive properties of a set of diagnostic criteria. Thus, the DSM-5 criteria for bipolar I disorder for example are indeed descriptive—no one disputes that—but are not merely descriptive. They also point to a real clinical condition that carries causal implications and explanatory weight.
Accordingly, bipolar I disorder is reasonably held to be the causeof a patient’s manic or depressive symptoms. That these symptoms are also part of the diagnostic criteria for bipolar I disorder does not in any way confer circularity on the causal claim. As Dr. Aftab puts it2:
“There is a perfectly legitimate sense in which depression can be said to affect how people think, feel and act, and in my view, it is misleading and inaccurate to assert otherwise.”
Crucially, we would add this: anything that can affect something else has causal efficacy.
All this is not to say that the major DSM diagnostic categories fully explainthe patient’s condition. It is very rare that we ever fully understand all the causes of the patient’s clinical condition, which may number in the thousands, often including many psychodynamic, psychosocial, and characterological factors. But the DSM diagnosis is at least the beginning of a causal explanation, as Aftab points out.2
Finally, we agree with Drs K and V (and with Aftab) that there is some risk of reifying a psychiatric diagnosis—as if it were a physical object or material thing sitting inside the patient and mechanically or physiologically causing symptoms. But this risk can be mitigated by using—and discussing with the patient—the biopsychosocial approach embodied in the case formulation, which (to repeat) is a mandatory part of the DSM diagnostic process.
Much more could be said in response to Drs K and V, but we will need to defer that for now. We appreciate the opportunity to present our views, and we hope that readers will find this exchange stimulating and useful.
Dr Pies is Professor Emeritus of Psychiatry and Lecturer on Bioethics and Humanities, SUNY Upstate Medical University; Clinical Professor of Psychiatry Emeritus, Tufts University School of Medicine; and Editor in Chief Emeritus of Psychiatric Times (2007-2010). Dr Pies is the author of several books. A collection of his works can be found on Amazon. Dr Ruffalo is an assistant professor of psychiatry at the University of Central Florida College of Medicine in Orlando and adjunct instructor of psychiatry at Tufts University School of Medicine in Boston, Massachusetts.
References
1. Indical. Collins Dictionary. Accessed August 23, 2024. https://www.collinsdictionary.com/us/dictionary/english/indicial
2. Aftab A. The explanatory value of descriptive diagnosis. Psychiatry at the margins. July 13, 2024. Accessed August 23, 2024. https://www.psychiatrymargins.com/p/the-explanatory-value-of-descriptive?utm_campaign=reaction&utm_medium=email&utm_source=substack&utm_content=post
3. Dewanti D. Semiotic analysis of Ferdinand De Saussure’s structuralism on “Energen Green Bean” advertisement. June 21, 2023. Accessed August 23, 2024. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4487450