MUSings on Functional Disorders

Richard sykes’s paper on medically unexplained symptoms (MUS) and its criticism of the inference that they must therefore be psychogenic makes a valuable contribution to the debate around issues of terminology in diagnosis and medical explanation. I would like to broaden the debate by suggesting that looking more explicitly at the context in which terms are used can enhance both clarity and honesty, which is Sykes’s main objective. In doing this, however, I want to defend the use of the term “functional” in some contexts, and also to challenge the inference that physical and mental are antonyms.

The loss of the term “functional” in a diagnostic context would, I believe, be a mistake. There is not time in this paper to explore the full richness and complexity of “functional,” but at the root of the definition of function are the ideas of “purpose” and “intent” and their relationship with “outcome.” After an introduction, I will outline three ways in which functional is commonly and properly used in explaining health problems: (1) enhancement of the functional ability of a patient in a global sense; (2) the inevitable although undesired consequences of normal body physiology; and (3) the unnecessary and undesired consequence of maladaptation, that is, “normal” but inappropriate physiological activity.

Sykes quite rightly highlights the ambiguity of the words “functional,” “nonorganic,” and “somatization.” He concludes that where there is no evidence that the problem is psychogenic, these terms should be replaced with more precise ones that do not imply psychogenic. He suggests the word “idiopathic” as a replacement, although to my mind idiopathic infers psychogenic just as much as functional does, and worse, may bam-boozle the patient into thinking either that they have a real medical condition, or that the clinician understands the problem, when they do not.

Part of this is a call for honesty; if the cause of the problem is unknown, it is better to admit to it than use terms like functional or (I would add) idiopathic. However, it is not clear whether Sykes is suggesting that these terms are only synonyms for “do not know,” or whether clinicians using them believe, assume or intend them to mean something that may or may not include “psychogenic.” In addition, the concepts of “physical” and “mental,” which underpin the main arguments, may not be as polarized as he assumes. To take an analogy: I may have a computer fault that is the result of software being incompatible with the hardware. Because there is no fault per se with either, is it a physical or a “mental” problem? The answer is neither; it is the wrong question and the fault lies at another level, in a bigger system of organization that includes (among other things) design. There is something about the way the whole operates that is dysfunctional and not explained by examining either part.

We do not just have to be dealing with a fully dysfunctional system. Suppose I find that a new application that I have installed on my computer causes my printer to crash. The application does what it is meant to do, so it is not dysfunctioning, but I have this irritating phenomenon that is “functional” in the sense that it is a consequence—albeit unintended—of the application functioning. The explanation for why my printer keeps crashing is that it is a functional consequence of using the application. My argument is that there are parallel situations in human health.

Enhancing Patients’ Global Ability

It is uncontentious that health care practitioners work to improve patients’ functionality. The purpose of treatment and the aims of management are to enable patients to live their lives and achieve their goals as effectively and efficiently as possible by minimizing suffering and enhancing physical and mental ability. But this is not the sense in which Sykes is understanding and criticizing the term functional.

Instead of being an intended outcome or purpose, he believes that “functional,” when used of MUS, implies the undesirable consequence of a psychological state, where “psychological state” is inferred from the fact that there is no known physical...