Descriptive Labels Are Not Causes, No Matter How Hard You Try: A Response to Pies and Ruffalo

Anbuselvan/AdobeStock

This article is a response to the article “No, Psychiatric Diagnoses Do Not Reflect “Circular Logic”” by Ronald W. Pies, MD, and Mark L. Ruffalo, MSW, DPsa.

We thank Ronald W. Pies, MD, and Mark L. Ruffalo, MSW, DPsa, for their interest in our paper on the misrepresentation of depression by health institutions.¹ We would like to respond to their contention that our arguments are “ill-founded, misleading and fallacious.”²

A Misguided Analogy

In critiquing our study, Pies and Ruffalo use a volcano analogy to make the point that causes and effects can be described at different levels of explanation. Yes, of course they can. Nobody claimed otherwise. Contrary to what Pies and Ruffalo imply, our study did not argue that psychiatric diagnoses are causal explanations at an undesirable level.

Our study rests on 2 keystones that seem to us quite difficult to dispute: (1) That psychiatric diagnoses are descriptive in nature, as explicitly stated by the DSM (page XLI),³ and (2) that using a descriptive diagnosis as a causal explanation for the symptoms it labels is logically circular.

Psychiatric diagnoses are not causal explanations at all, making the volcano analogy poorly considered at best. In fact, it is difficult to find anything about a psychiatric diagnosis that would be analogous to a volcanic eruption causing the destruction of Pompeii.

An eruption of a volcano destroying a city is a case of a physical event causing a second physical effect. This is not what psychiatric diagnoses are (regardless of your favored philosophy of mind). Psychiatric diagnoses are not made by identifying a physical event that has caused a second physical event, unlike the analogy misleadingly suggests. At our current state of knowledge, no physical event or process can be pointed to as the cause of any psychiatric disorder, and the DSM explicitly acknowledges this. In fact, the contrary is true: If a physical event, such as a traumatic brain injury or the ingestion of a chemical substance, is known to cause the symptoms, a diagnosis of depression is inappropriate.

Pies and Ruffalo then make the declaration that psychiatric diagnoses are causal (“level 1”) explanations. This is a profoundly mistaken claim, as the DSM explicitly states otherwise (page 25).³

It seems to us that Pies and Ruffalo are confusing descriptions of states with causal claims, perhaps in part because they are also confused about what causation means. Causation refers to the relation between cause and effect, or the act of bringing about an effect.⁴ Consider these examples:

1. Alex is experiencing depressed mood, loss of pleasure, insomnia, weight gain, and psychomotor agitation.

2. Alex has a fever and a headache.

These are descriptions of states, not causal claims. Contrast them with these statements, which are causal claims:

3. Alex is experiencing depressed mood because their partner wants a divorce.

4. Alex has a fever and a headache that are caused by a virus.

Psychiatric diagnoses are of the first kind. They are labels for situations in which given diagnostic criteria are met.

Circularity Misunderstood

In addition to their misleading analogy, Pies and Ruffalo confuse 2 different kinds of circularity claims—one that we made, and one that we did not.

It is mystifying to see the authors quote several passages verbatim from our paper, only to attack a claim we never made. Unlike Pies and Ruffalo imply, we did not claim that psychiatric diagnoses, in and of themselves, reflect circular reasoning. To be clear: 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.

There is nothing circular about saying that the eruption of a volcano caused the destruction of Pompeii, but it is circular to say that the diagnostic label headache explains what causes the throbbing sensation in my head. As we point out in our paper, a medical condition can cause the symptoms if and only if it is conceptually independent from them.5Invoking a descriptive diagnosis as a causal explanation for its diagnostic criteria is circular because the former is, by definition, a descriptive label for the latter. There can, of course, be other legitimate uses for a descriptive diagnosis, but neither headache nor major depression are explanations or causes for their diagnostic criteria.

Perplexingly, Pies and Ruffalo quote a footnote from our paper in which we clarify that the symptoms themselves can still, of course, cause other things. Pies and Ruffalo believe that this somehow shows how our “circularity charge collapses under its own weight.”

It does no such thing. Things like negative emotions, anhedonia, insomnia, and weight gain can and do have consequences for our thoughts and actions, and there is nothing circular about describing their consequences, either alone or in combination.

Case Formulations: A Case in Point

Interestingly, Pies and Ruffalo inadvertently help to demonstrate one way to avoid circular claims in practice. Pies and Ruffalo assert that a thorough psychiatric evaluation includes more than a diagnosis, most importantly a case formulation. They contend that “the case formulation very clearly provides substantive, explanatory content for the patient’s condition—not merely a recitation of the patient’s symptoms.”

This is a relevant point. Unlike Pies and Ruffalo seem to believe, however, it does not refute our criticism of circular claims but rather helps to show a way to circumvent the problem. The critical difference is that while DSM diagnoses are defined by their diagnostic criteria, case formulations are not. It is not logically circular, for example, to describe (as one presumably can do in a case formulation) the life circumstances that have led to the individual meeting the diagnostic criteria for a given DSM category.

Moreover, the "substantive, explanatory content” that is “not merely a recitation of the symptoms” is often likely to be important for understanding what is wrong and what can and should be done: I can experience depressed mood, loss of pleasure, weight loss, insomnia, and psychomotor agitation because I have (say) been unfaithful to my partner and feel overwhelmed by guilt that I cannot handle; or because I live in constant fear that my child will commit suicide; or because it has dawned on me that I have irredeemably wasted my life in the pursuit of meaningless things. The same diagnostic criteria can mean very different things, depending on what is causing them.

Other Aspects That Do Not Affect Our Points

Pies and Ruffalo invoke several additional points seemingly in opposition to our criticism of circular statements: (1) That psychiatric diagnoses are not defined solely by subjective complaints but also by “objective signs” such as weight loss or psychomotor agitation or retardation, (2) that psychiatric diagnoses serve to rule out physical diseases, and (3) that psychiatric diagnoses serve to discriminate between different forms of psychiatric problems. All this is inconsequential for the circularity problem. The fact remains that psychiatric diagnoses are descriptive labels defined by their diagnostic criteria, and the label does not cause the symptoms.

Pies and Ruffalo also attempt to refute our criticism of circular statements by claiming that psychiatric diagnoses have “external validators,” such as “characteristic biomarkers,” “genetic risk factors,” and “course of illness.” However, there are currently no established “characteristic biomarkers” that could be used to diagnose conditions such as major depression or schizophrenia.6 Genetic associations are small and explain little of the variance in outcomes. Reliable patient-level predictors are available neither for “course of illness” nor “typical response to treatment.”

In sum, we do not see how Pies and Ruffalo’s claim is warranted that “it makes sense to speak of these conditions as causing symptoms.”

Importantly, however, nowhere in our paper do we claim that the experiences described by psychiatric diagnoses are metaphorical, mythical, or unreal, unlike Pies and Ruffalo mistakenly suggest. That a headache diagnosis does not cause or explain the pain in the head does not make the pain any less real. It is perfectly possible to take human suffering seriously without invoking logically circular causal entities.

Wishes for Future Explanations

Finally, Pies and Ruffalo use Parkinson disease to express their hope that constellations of symptoms and signs, such as tremor and stiffness, can sometime in the future be linked with an identified pathophysiological mechanism, such as loss of nerve cells in the substantia nigra. While such mechanisms have been found in some cases, there are other historical examples in which seemingly cohesive clusters of symptoms and signs have turned out to encompass heterogeneous disease processes (as in diabetes type I and II), and others in which symptom-based classifications have turned out to be blatantly incorrect (as in Galen’s classification of different forms of fever).

At this point, it is an article of faith whether unifying disease mechanisms will be discovered for psychiatric diagnoses as currently defined by the DSM. Today, psychiatric diagnoses such as depression and schizophrenia remain hypothetical entities describing heterogeneous and overlapping patient populations, and their validity is widely questioned.^5-9 The lack of validity of DSM categories is an essential reason for their decreased popularity in research, and many authors have developed alternative frameworks.^5,7,9

Why Should We Care?

We are far from the first to point out the problem with circular explanations in psychiatry.^10-13 As Read and Moncrieff have noted, depression is commonly depicted as “somehow causing abnormal feelings and behaviors, as if itwere a physical condition, even though those same feelings and behaviors form the criteria for the diagnosis in the first place.”¹¹

Other authors have made similar and related points before. Kendell and Jablensky pointed out already over 20 years ago: “Unfortunately, once a diagnostic concept such as schizophrenia or Gulf War syndrome has come into general use, it tends to become reified. That is, people too easily assume that it is an entity of some kind that can be invoked to explain the patient’s symptoms and whose validity need not be questioned.”¹⁰

It matters greatly how we conceptualize the problems we are seeking to address. Part of the reason we wanted to call attention to circular causal claims in psychiatry is that they likely have negative consequences for patients, clinicians, and society at large. For one, promoting an understanding of depression as a disease that causes low mood, loss of pleasure, and other symptoms creates an illusion of an independent entity, outside a person’s life, causing the distress and impairment. This can lead to decreased perceptions of agency, as well as other less adaptive beliefs.¹⁴ Instead of implying that an external disease entity is causing the symptoms, it is more accurate and more useful to think of depression as a nonspecific symptom, much like a headache, a fever or a cough, or as a functional signal to adverse circumstances in life.^14,15 Being clear about what psychiatric diagnoses mean would also help us societally to address the actual causes of the suffering more effectively.

Moreover, if circular claims are presented together with unfounded claims about purported brain mechanisms, they may further bias individuals towards falsely assuming that biological causes and mechanisms have been identified for psychiatric problems. In our study, we identified several concerning examples of causal language being paired with biologically reductionist statements that are unsupported by scientific evidence. For example, “[Depression] is a chemical imbalance in your brain that needs to be treated” (Johns Hopkins University), or, “It is believed that chemical changes in the brain are responsible” (Medline plus). It is worrying that such unsupported statements are presented as objective fact by medical authorities, as this not only misleads patients and clinicians but also jeopardizes public trust in medicine and science.

As Mirowsky and Ross summarized 35 years ago, “No one should forget that we are talking about the disturbing or disruptive thoughts, feelings, and behaviors of people, and not about unseen entities that are somehow the cause of it all.”¹³

Dr Kajanoja is an MD specializing in psychiatry, and a researcher at the Department of Psychiatry, University of Turku Finland. Dr Valtonen is a neuropsychologist, a member of the evidence-based medicine research group FICEBO at the Faculty of Medicine, University of Helsinki, and faculty at the University of the Arts in Helsinki, Finland.

References

1. Kajanoja J, Valtonen J. A descriptive diagnosis or a causal explanation? Accuracy of depictions of depression on authoritative health organization websites. Psychopathology. 2024;1-10.

2. Pies RW, Ruffalo ML.No, psychiatric diagnoses do not reflect “circular logic.” Psychiatric Times. June 26, 2024. https://www.psychiatrictimes.com/view/no-psychiatric-diagnoses-do-not-reflect-circular-logic

3. American Psychiatric Association. Diagnostic and statistical manual of mental disorders, version 5 (DSM-5). 2013;21(21):591-643.

4. Kim J. Causation. In: Audi R, ed. The Cambridge Dictionary of Philosophy. Cambridge University Press; 1995:110-112.

5. Borsboom D, Cramer AOJ. Network analysis: an integrative approach to the structure of psychopathology. Annu Rev Clin Psychol. 2013;9:91-121.

6. Across the divide. Nature. 2013;496(7446):397-398.

7. Insel TR. The NIMH Research Domain Criteria (RDoC) Project: precision medicine for psychiatry. Am J Psychiatry. 2014;171(4):395-397.

8. Frances AJ, Widiger T. Psychiatric diagnosis: lessons from the DSM-IV past and cautions for the DSM-5 future. Annu Rev Clin Psychol. 2012;8:109-130.

9. Owen MJ. New approaches to psychiatric diagnostic classification. Neuron. 2014;84(3):564-571.

10. Kendell R, Jablensky A. Distinguishing between the validity and utility of psychiatric diagnoses. Am J Psychiatry. 2003;160(1):4-12.

11. Read J, Moncrieff J. Depression: why drugs and electricity are not the answer. Psychol Med. 2022;52(8):1401-1410.

12. Hyman SE. The diagnosis of mental disorders: the problem of reification. Annu Rev Clin Psychol. 2010;6:155-179.

13. Mirowsky J, Ross CE. Psychiatric diagnosis as reified measurement. J Health Soc Behav. 1989;30(1):11-25; discussion 26-40.

14. Schroder HS, Devendorf A, Zikmund-Fisher BJ. Framing depression as a functional signal, not a disease: rationale and initial randomized controlled trial. Soc Sci Med. 2023;328:115995.

15. Fried EI, Nesse RM. Depression is not a consistent syndrome: an investigation of unique symptom patterns in the STAR*D study. J Affect Disord. 2015;172:96-102.