Opinion Functional Somatic Disorder: a Post-Medical event Stress Disorder? 2026 Horn et al

[Andy]

Abstract​

Functional somatic disorders (FSD) are characterized by persistent and bothersome physical symptoms associated with impairment or disability. FSD have a significant impact on quality of life, whilst concurrently presenting clinicians with considerable challenges, due to the difficulty in comprehending the reasons for and the mechanisms by which physical symptoms persist.

A history of medical events (e.g., severe infections, injuries, or invasive procedures) is common in patients with FSD and has been identified as a potential trigger factor. The emergence of physical symptoms and health-related psychological symptoms after a stressful medical event provides a compelling basis for comparison with post-traumatic stress disorder (PTSD). This paper hypothesizes that a subset of FSD cases can be conceptualized as a "post-medical event stress disorder," a condition analogous to PTSD.

This paper re-interprets FSD symptoms as consequences of a stressful medical event, detailing the psychopathological processes that may explain their emergence and persistence in a specific subset of patients. While acknowledging key differences between FSD and PTSD, we propose a therapeutic framework for this specific subgroup of FSD patients that draws on successful PTSD treatment models. We conclude by outlining future research to further explore and validate this proposed PTSD-like mechanism.

Paywall

 

[SNT Gatchaman]

Functional somatic disorders (FSD) is an umbrella term for various conditions (ranging from fibromyalgia and chronic fatigue syndrome to disorders of gut-brain interaction) characterized by persistent and troublesome physical symptoms that arise from complex brain-body interactions [1].

[1] is Functional somatic disorders: discussion paper for a new common classification for research and clinical use (2020)

Beyond the physical burden, FSD is characterized by specific psychological features, notably focused attention on bodily sensations, catastrophizing, and avoidance behaviors.

Current evidence on the development of FSD is best represented by biopsychosocial vulnerability-stress models, which distinguish between predisposing, triggering, and maintaining or aggravating factors.

As in fear conditioning, this phenomenon might be understood through the lens of associative learning: physiological signals present during a stressful medical event can become conditioned stimuli, acquiring threatening value through respondent (Pavlovian) conditioning.

Specifically, we propose that a common physiological signal present during the initial medical crisis (e.g., increased respiratory rate during a respiratory infection) becomes a conditioned interoceptive trigger through association with acute symptoms (e.g., breathlessness). The subsequent occurrence of this trigger, even during a benign state (e.g., increased respiratory rate during exercise), automatically reactivates the re-experiencing of the other original symptom (i.e., breathlessness) in the absence of the original cause (i.e., respiratory infection).

Within the predictive coding framework, this process is reflected in the development of overly precise prior expectations of symptoms, which can dominate perception even in the face of minimal or absent sensory input. This model suggests that symptom perception in certain FSD presentations is shaped predominantly by top-down processes, including prior experiences and expectations formed during the initial medical event. In a second phase, often marked by increased uncertainty or catastrophizing, attentional mechanisms may reinforce the perception of symptoms through somatosensory amplification, a phenomenon whereby attention selectively enhances the salience of bodily sensations and amplifies their perceived intensity and unpleasantness.

All the hits.

From Table 1: Similarities between FSD and PTSD

Predisposing: Female sex, lower socioecomonic status, lower social support, childhood trauma

The aim is to support clinicians in making sense of a disorder that is often difficult to recognize and may lead to stigma or patient rejection. By acknowledging the role of a physical triggering event while framing symptom persistence as the result of involuntary brain-based maintaining mechanisms, this restricted model may help foster therapeutic alliance and make psychological and behavioral interventions more acceptable, both for patients and healthcare providers.

 

[Peter T]

This makes me think of a friend who had persistent chest pain following heart surgery. This persistent FSD severally restricted the person’s movement and inexplicably it did not respond to psychological intervention or to exercise (or at least as much exercise as the extreme pain allowed). Most obviously it was a response to the stress of the surgery.

After eighteen months the psychopathology became elucidated. A naive young Doctor, who presumably did not understand that this was likely to exacerbate the symptoms, who was not on board with the correct narrative, foolishly agreed to do a chest X-ray. An eleven inch stainless steel surgical implement was found within the patient’s chest cavity.

Even more surprisingly the symptoms resolved after a second surgery that removed the medical implement. Surely the trauma of yet another medical intervention should have made the patient worse.

 

[Hutan]

Surely the trauma of yet another medical intervention should have made the patient worse.

by persistent and bothersome physical symptoms

Ah, those bothersome physical symptoms, they are just so.... bothersome.

and troublesome physical symptoms that arise from complex brain-body interactions

Even troublesome. And those 'complex brain-body interactions', where the brain manages to not be of the body. Very tricky indeed.

How fortunate we are that Horn et al have it all worked out. There's just the matter of how a minor gastrointestinal infection with a bit of vomiting, the sort of thing that I and even my two children had recovered from a number of times, was somehow so traumatic that we three all suddenly catastrophised and avoided enough to develop ME/CFS.

we propose a therapeutic framework for this specific subgroup of FSD patients that draws on successful PTSD treatment models. We conclude by outlining future research to further explore and validate this proposed PTSD-like mechanism.

ah, a proposed therapeutic framework? So, this is just an idea, further research required of course.

 

[Turtle]

That's how BS becomes BPS.

 

[Utsikt]

Current evidence on the development of FSD is best represented by biopsychosocial vulnerability-stress models, which distinguish between predisposing, triggering, and maintaining or aggravating factors.

When you consider that the BPS model makes exactly zero testable predictions because it doesn’t say anything about how or to what extent any factors might interact, it’s no wonder that whatever «evidence» they think they have fit with the so-called model.

 

[rvallee]

LLMs are already way more original and smarter than this reheated garbage. It's not even a close contest either. It's nothing like "this article has ChatGPT vibes" that is common criticism, it's literally much worse than what LLMs would produce from a barely competent prompt.