The first definition is broad, the second narrow. O’Leary notes that the latter – which she distinctly refers to as ‘psychogenic symptoms’ or ‘psychogenic diagnosis’ – is the most common definition of MUS in research and practice. [4] This implies two things: 1) that MUS are commonly reified (‘thingified’) into a psychogenic diagnosis and 2) that the causation of symptoms is commonly understood to be primarily unidirectional. [5]

This is significant because proponents of the narrow definition of MUS maintain this position based on the alleged merit of philosophical nondualism. This rejection of mind-body dualism (attributed to medicine’s monistic biomedical model) advances the idea that clarity about the need for specifically biological care is not justified on philosophical grounds.

The holistic biopsychosocial model is often invoked in this plea for vagueness between the biological and psychosocial or etiological ambiguity. [6] It can be questioned what the merits of vagueness are in the doctor-patient context.

Special pleading to treat the need for medical care for MUS as an ontological problem (that is, to theorize about the nature of reality) singles out certain healthcare needs as more theoretical and encourages doctors to operate outside their realm of expertise.

If the direction of causation is taken for granted (psychogenic), this also means MUS cannot logically be considered etiologically ambiguous. Sociologist Angela Kennedy argues that

O’Leary, on the other hand, argues that the ‘vagueness thesis’ is based on reductive holism (an oxymoron) which reduces the mind to the brain. [8] It stands to reason that the position of proponents of a narrow definition of MUS is philosophically incoherent. That the analytical biopsychosocial model does not safeguard against over- or underrepresentation of one of its three domains (biological, psychological or social) has been acknowledged in literature. [9] That this is the case with MUS is evidenced by the practical outcome that cognitive behavioral therapy (CBT) – reattribution – is the central treatment option. [10] Nevertheless, proponents of this approach maintain that it is superior to the biomedical model, which is criticized for reducing illness to biological processes.[11]

Etiological ambiguity is shown to have a practical purpose, however. It is encouraged by proponents of the narrow definition of MUS as a strategy to avoid exam-room conflict between doctor and patient. Conversely, etiological ambiguity is not practiced amongst themselves (as doctors and researchers). [12] In addition to conceptual ambiguity, there is linguistic ambiguity surrounding MUS. Some linguistic expressions known to be used in this context are: ‘”psychological”; “psychogenic”; “somatization”; “somatoform”; “psychosomatic”; “conversion”; “functional”; “hysteria” and “hysterical”; and “neurasthenia”.’ [13]

Some of these terms in particular can, more than being contiguous or approximately synonymous, be construed as forms of doublespeak. ‘Functional’ is probably the best example of this. A short report, ‘The function of “functional”: a mixed methods investigation’, signals ‘considerable ambiguity’ in dominant uses of the word. It concludes:

The term ‘functional’ was purposefully selected to be more palatable to patients. Upon closer inspection, this seems to not have transpired in good faith, as a discrepancy of definition likely existed (but was not acknowledged) between researchers and those researched. [15]

Why are such asymmetrical conceptual structures cultivated for MUS? Historically, the field has been dominated by a subdiscipline of psychiatry called psychosomatic medicine (more recently consultation-liaison psychiatry). Psychogenic diagnosis was first codified in the Diagnostic and Statistical Manual of Mental Disorders (DSM) in the 1980s as ‘somatoform disorder’. With it, the 19th century construct of hysteria was, in effect, rebranded without being significantly altered conceptually. The new name was meant to avoid ‘resentment and resistance’ from patients. [16] Correspondingly, it was psychiatrist Eliot Slater who commented around that time: ‘In the main, the diagnosis of “hysteria” applies to a disorder of the doctor-patient relationship.’ [17]

It seems fair to suggest that asymmetrical conceptual structures in this field may not so much be a flaw, but a feature. The supposed merit of allowing doctors to override patients’ autonomy and bypass informed consent by employing ambiguity (to avoid compromising their duty of truth telling) is highly problematic. [18] Nonetheless, it has been observed that

It is appropriate to argue that the psychogenic dismissal of MUS constitutes epistemic injustice – a term coined by philosopher Miranda Fricker. This theoretical framework is premised on an interconnectedness between the philosophical branches of epistemology (concerned with knowledge) and ethics, and on the sharing and production of knowledge as a valued good.

Inequalities in access to and participation in the formation of knowledge are not just considered ethically wrong, they are thought to cause primary and secondary harms. More specifically, these harms can be understood as repercussions of two distinct but interrelated forms of epistemic injustice: testimonial and hermeneutical injustice.

Testimonial injustice refers to a credibility deficit a speaker obtains due to negative stereotyping. The speaker’s contribution to ‘the epistemic enterprise’ is excluded, dismissed or relegated to a lower status. Hermeneutical injustice refers to a co-occurring ‘collective shortfall in our shared conceptual resources’. Involved parties are affected asymmetrically in terms of advantage and disadvantage. Essentially, epistemic injustice highlights a juxtaposition of credibility deficit and credibility excess. Within this context, this means healthcare suffers under conceptual impoverishment in conjunction with the downgrading of patient input. [20] In concreto, patient harm occurs because

Besides strategies of exclusion (as evidenced by etiological ambiguity), the field of MUS displays marked strategies of expression. These pertain to interpretations – by doctors and researchers – of patients’ forms of expression as evidence for lack of rationality and lack of understanding of ‘appropriate’ modes of expression. [22]

Indeed, the dysphoric characterization of patients’ behaviors, thoughts, actions and characters that accompany psychogenic diagnosis is striking. [23] In biopsychosocial discourse it is not unusual, for instance, for patient negativity towards psychotherapy to be interpreted as a sign of ‘illness seeking behaviors’. [24] Strategies of expression seem more pronounced in controversial MUS-adjacent illness categories.

Because MUS are difficult to define, doctors are known to apply different rationales in their classification, often not under MUS code-categories but under organ-related codes. This blurs the lines between MUS and contested illnesses such as fibromyalgia, chronic Lyme disease and ME/CFS. [25]

Most publicly, patients with ME/CFS – a denomination reflective of dissent – have been maligned for resisting a biopsychosocial framework for their illness in favor of a biomedical one. [26] Historically, long-term post-viral symptoms following viral outbreaks have often been likened to ME/CFS. [27] Its co-optation into psychosomatic medicine, intended to secure scientific credibility for the discipline, turned it from a quintessential post-viral syndrome into a quintessential psychosomatic condition. [28] As a result, patient resistance has been dismissed; for example as ‘bigotry against people with mental illness’. [29]

The express need for psychological support notwithstanding, it is not met due to the preference for corrective therapies within this framework. [30] Evidence of iatrogenic (therapy-induced) harm found with both central treatment options informed by the biopsychosocial model – CBT and graded exercise therapy (GET) – is often not (fully) recognized. [31] This can be partially attributed to a general lack of recognition that behavioral and psychosocial interventions can inflict harm. [32] The problem with exercise is obscured by an emphasis on (nonspecific) fatigue instead of (illness-specific) exertion intolerance.

The incongruent illness narratives have at one point been described as ‘a conceptual deadlock between patients and medical authorities’ and even given rise to ‘militant trope’.

Patients have been accused, typically by leading psychiatrists, of stalking, harassment, and intimidation as well as of abusing the Freedom of Information Act (FOIA). [33] These accusations – ironically at odds with the level of disability associated with the illness – were ruled to be unsubstantiated in a first-tier Tribunal. [34] Furthermore, globally respected health authorities have made a paradigmatic shift towards the patient perspective: ‘what used to be a chasm between patient and professional perspectives has now become a chasm between professionals’. In this sense, ME/CFS is considered a cautionary tale for the psychogenic dismissal of MUS and contested illnesses. [35]

At the time of writing this article, we are entering into the seventh month of the Coronavirus (COVID-19) pandemic. After the first wave, there is an emerging picture of a significant minority of (confirmed or suspected) cases with prolonged symptoms.

Among these ‘long-haulers’ are many doctors, now rallying (with some success) for recognition by their national government and health services of what is most commonly called ‘long COVID’ or, somewhat less commonly, ‘post-COVID syndrome’. [36]

Although symptoms and evidence are suggestive of multisystem involvement, often accompanied by ‘COVID-19 fatigue’ and ‘post-exertional symptom exacerbation’, affected doctors are raising concerns about dismissal as ‘anxiety’ in doctor-patient encounters. Not untimely, ‘[m]ass psychogenic illness – which used to be referred to as mass hysteria’ has been invoked as an explanation for local outbreaks.

The risk of psychogenic dismissal is further increased by limited testing and false negatives (necessitating a clinical diagnosis). Long-haulers in search of rehabilitation are typically finding recommendations of CBT and GET unhelpful, discerning a ‘serious disconnect’ with their own experience. Long-hauler doctors are pleading for patient contribution rather than ‘a purely top-down venture’. In a manifesto in the BMJ

If all of this sounds familiar, it will probably not come as a surprise that the recommendation of GET was, in fact, informed by the ME/CFS guidelines. One that patients have rallied to change (without success) for years and which, at the time of NICE issuing its statement, explicitly remained in effect for ME/CFS. [38]

In a strange twist of fate, long-haulers, including doctors, are turning to the ME/CFS patient community for support. [39] Because funding for biomedical research has not been commensurate, [40] the latter has little more to offer than pacing, an adaptive self-management strategy to prevent relapses. Some long-hauler doctors note that the situation has improved their understanding of ME/CFS. [41] Others prefer to distance long COVID from associations with post-viral syndromes. [42] A few double down on the wisdom of a more philosophical approach to MUS, focusing on their response to having long COVID in favor of the cause. [43]

Many patients with poorly understood pre-COVID (not seldom post-viral) symptoms seem to have mixed feelings about what may or may not be a reversal of opinion. In their current predicament, the most vocal long-hauler doctors have become acutely aware that it is not in their best interest to get lumped into a group based on a lack of understanding because this is not safe from a healthcare point of view, and risks obstructing investigation of the underlying pathology. [44]

The management of medical uncertainty remains a problem area and long COVID is hardly the first challenge of its kind. A perspective in The Lancet drew an interesting parallel with the pandemic of 1889-92, the lesser known ‘Russian influenza’. Neurological post-influenza symptoms received a variety of names: ‘“neuralgia”; “neurasthenia”; “neuritis”; “nerve exhaustion”; “grippe catalepsy”; “post-grippal numbness”; “psychoses”; “prostration”; “inertia”, “anxiety”; and “paranoia”’.

What is notable is the observation that these nervous sequelae were understood as neurasthenia rather than hysteria, and therefore as somatopsychic (instead of psychosomatic). This is related to a general pattern of men being more affected. For long COVID, however, this pattern is reversed. Nonetheless, the authors express hope that similar sympathy will be shown towards long COVID.

The engagement of doctors at the time is attributed to elements such as less rigid demarcations between specialties and fluidity of ideas regarding disease causation which is likened to ‘a broader web of biopsychosocial meanings’ that invite ‘patients’ narratives of illness’. [45] Meanwhile, an article in JAMA described the medical gaslighting of long-haulers as ‘harkening back’ to a bygone era of being written off as hysterical. [46]

An editorial in Nature calling for patient involvement in the terminology and the definition of recovery for long-term COVID symptoms explicitly acknowledged failures of the more recent past in this regard, stressing that ‘[i]t is crucial that those with the condition are listened to in a way that, tragically, people with ME/CFS were not’. [47]

Certainly, if the pandemic can serve as a catalyst for progress in the management of medical uncertainty, it would be a silver lining to an otherwise catastrophic event. However, it would be premature to consider psychogenic dismissal a thing of the past. (If anything, new classifications are trending towards it.) [48] This would also seem to make the revival of late Victorian elements something of a redundant exercise. The appeal of psychogenic explanations, their lack of probabilistic coherence with the rest of medical knowledge notwithstanding, [49] is an extant one:

The common notion that psychiatry’s biopsychosocial model will safeguard against this is remiss.

Case in point: my opening anecdote about that ME/CFS media campaign. What I saw, was the same doctor-patient dynamic that, historically, seems to have a way of arising in the face of medical uncertainty. I saw this stereotypical role division of credibility excess and credibility deficit play out in real time. I saw patients left in distress and despair, some openly contemplating suicide on social media. But I also saw some professionals speak up on their behalf; like a professor in psychology who responded with the blog post ‘If you spend 20 years gaslighting your patients, perhaps you should think twice before accusing *them* of trolling *you*’. [51] And as the saying goes, this is the definition of madness: doing the same thing over and over again and expecting a different outcome. If this historical pattern is not recognized, we are bound to perpetuate it in some way, shape or form. Indeed, in post-COVID times there is a realistic chance that many of us will have learned this first hand. Paul Garner, professor of infectious diseases, who has on several occasions written about his experience as a long-hauler, reflected on it as follows: