For entrée to the mindset behind "psychogenic illness" one need go no farther than the humble hiccup. Consider the published case of the 31year old epileptic retarded institutionalized male with refractory hiccup so severe that his hiccups "caused" melena—doctor-lingo for "black tarry stool," from bleeding high in the gastrointestinal (GI) tract. (The blood oxidizes in transit, turning dark.) When a tube was inserted in his nose for some incidental reason, the man's hiccups ceased - clearly punishment had cured the hiccups, from which it followed that the cause was psychogenic.
Thereafter each time the poor man's hiccups commenced, attendants first menaced him with a nasogastric tube (which never worked), then molested the back of his throat with it, reliably aborting the hiccup bouts. After some months of nasopharynx torment, the man's hiccups resolved, and so did the melena, proving their punishment worked.
Except hiccups don't cause melena, and nasopharyngeal stimulation doesn't cure hiccups by punishment. Manifestly, a GI woe caused the melena, simultaneously irritating the input arm to the hiccup reflex—the vagus nerve, which traverses the GI tract. GI afflictions are the chief cause of persistent hiccup; and nasopharynx stimulation the most effective reported cure for hiccups – working equally in unconscious people, with anesthetic-induced hiccup – presumably oblivious to "punishment." (Like many hiccup cures, this stimulates the vagus higher in its trajectory, interrupting the reflex.)
One defective case does not invalidate a phenomenon. Surely other "psychogenic" hiccup reports rest on a sturdier foundation?
A woman's hiccups were "psychogenic" because, it was announced, they were precipitated by an emotionally significant event. The touted trigger: her daughter's age—the age she had been when herself abused. (Hiccup is the obvious outcome.) Causal affirmation rested on a history of medical maladies triggered by emotionally significant events. A fall on ice was chalked up to an emotional event in the general temporal vicinity. Then there was her history of morbid fear of uterine cancer, so powerful it "caused" uterine bleeding, then led to uterine cancer itself. (The possibility her fear of uterine cancer was justified – indeed, triggered by the abnormal uterine bleeding, which was actually due to the cancer that was later diagnosed—was not considered.)
In other instances, the psychogenic defense rested on cessation of hiccups with sleep. Proof positive. Except for pesky counterexamples a reading of the literature would expose. Like the boy whose recurrent hiccups initially resolved with sleep – but then didn't. And then his medullary brain tumor was diagnosed. (The medulla exerts tonic inhibition to the hiccup reflex; damage disrupts this inhibition.)
A hiccup epidemic in a hospital ward was clearly mass psychogenic illness. Many contracted hiccups, so susceptibility to psychic contagion must have high penetrance. How then have friends, family and hospital roommates of the many other persistent hiccup cases been so spared? Might there be another explanation? How about: actual contagion. Streptococcus singultus had caused epidemic hiccup in the past, and could be passaged in rabbits causing them to hiccup. No effort to hunt for such a cause was made. ("Singultus" is "hiccup" in medicalese.)
A review of this literature in days of yore (graduate school) revealed no report of psychogenic hiccup in which positive evidence corroborated a psychogenic cause. Worse, the foundation for psychogenic illness itself was: supposition. There was no delineation of mechanisms by which such effects putatively occur, much less demand to prove such mechanisms were operating. Nor was there a clear exposition of what, precisely, was meant by psychogenic, which morphs for the convenience of the expositor.
Many psychogenic epithets surrendered to evidence. Ulcers were psychogenic—till Helicobacter pylori and NSAIDS usurped the blame. So was most low back pain. By 1987 Joukamaa et al had it partly right: "little is known about [low back pain's] aetiology, its natural history and its treatment. This may explain why the myth exists that low back pain is often psychogenic". This prescience was undermined (or peer-reviewers courted) when it was added that those afflicted with back pain were, however, apt to harbor neuroses, and on top of that, weak egos—a revision, they proclaimed, from the prior view, in which conversion hysteria and psychosis dominated causes of back pain. (It is remarkable how the advent of workplace ergonomics helped gird weak egos.)
The newly minted Somatic Symptom Disorder is the latest take on psychogenic illness, anointed in the last incarnation of the Diagnostic and Statistical Manual. (This is the tome that guides haruspication. I mean, psychiatry.) This dispenses with even the one requirement, lack of another cause, recognizing the pesky propensity for that lack to be sometimes - horresco referens—remedied, thus discrediting the doctor who declared the problem psychogenic. Now the doctor can skip the tiring pretense of actually looking for a cause, and if one is found anyway, he still saves face by virtue of the patient remaining impugned. (The condition is only "cured" when the patient shuts up about their symptom(s). This helps the doctor and healthcare system. Never mind the patient.)
The emperor never had clothes. The psychogenic designation is logically vacuous, not meaningfully defined so not falsifiable, grounded in petitio principii (circular reasoning)—and functions as an assault. It impedes a search, when warranted, for legitimate conditions, breaches patient-doctor trust, effectively abandons the patient, and blames him for his affliction while also casting the pall of mental infirmity. It adds to (rather than mitigating) the patient's travails, antithetical to the dictum primum non nocere—first do no harm—that had ought to guide medical care.
The psychogenic designation has long presumed that for any other condition, a standard of evidence must be met. Yet, for psychogenics, no standard is demanded: Ipse dixit. Proof by suggestion. Who could believe that? Someone who suffers from the delusion of:
Psychogenic illness—it's all in the doctor's head.
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NOTE: I don't presume physical ailments cannot have psychological triggers. Some "alternative medicine" approaches proffer putative means to discriminate which cases do, furnish testable hypotheses and effect cures—a standard beyond that which "mainstream" medicine adopts.