I think a part of this is online communities spring up around these diseases and a doctor telling you that you don't have it is basically them telling you they don't get to hang out with your friends anymore.
Better data exists for IBS on this line of thinking:
> The Illness Attitudes Scales (IAS) and the Beck Depression Inventory (BDI) were administered to 40 patients with irritable bowel syndrome (IBS) and these were compared with 35 patients with organic gastrointestinal (GI) disease, 37 depressed patients, and 40 healthy volunteers.
> All the patient groups had abnormal IAS scores compared with the healthy group, but these were most marked among the IBS patients with elevated scores on six out of the eight subscales. Three of these were specific to the IBS patients: bodily preoccupation, hypochondriacal beliefs and disease phobia.
Also - given medical developments in gut health on GABA, the gut-brain link is not so crazy. So your study could be a reverse causation.
After no physical ailments are detected, they should be treated by psychologists rather than physicians.
So if I'm not hyperchondriac, but am frustrated and stressed by (x) random symptom or covid related (y), or being off sick w/ "normal" Covid & struggling to regain energy, then if I'm emotionally distressed by it, then may develop IBS and fatigue symptoms on top of that - which then feeds into the loop...
(Said as someone for the last several months currently struggling with a whole bunch of symptoms and not managing to get any helpful diagnosis or area I can work on to improve things...)
I've long been curious what the ratio is in various situations like this. It seems the lynchpin for any argument for withholding support. I've only ever seen the equivalent of "well obviously" on both sides and never any data
As people understood what long covid was and does, people generally came around to the idea, but still (mainly online) people have this opinion that 'people must be making it up' - despite SARs being known to cause similar long term issues for some of those infected, and some people having long term impacts from Spanish Flu 100 years ago.
The body is a pretty complex thing, it can be difficult to determine the underlying cause of a symptom even if we do have an underlying understanding of what the body is doing (and sometimes we don't!).
Lyme disease can actually be detected. For IBS and long covid, you are making the "no true Scotsman" argument. Diagnosing those is basically filling a questionnaire asking in so many ways "do you feel like you have it?" The same is true for many mental illnesses, by the way. Not to discount people's experience of having these problems - they definitely are real - but since the "official" diagnose is very close to just people telling the doctor that they feel like they have it, self diagnosing is not as bad as you make it sound.
> people claim to have without evidence.
Bit of a technical note. Patients claim is the evidence on its own. Patient may be undiagnosed, but there is an evidence for such claim.
IBS, lyme disease, all sorts of allergies are very hard (and expensive) to diagnose. Some people have no money for doctors, and may not be even registered with GP.
If customer at restaurant says they have a peanut allergy, you better to believe them. Saying "there is no evidence for such claim" may get you in troubles very fast...
The idea of a hypochondriac making a spurious claim to IBS is pretty ludicrous. You know if you have the symptoms or not, and IBS is probably the best possible outcome for someone with chronic bowel symptoms.
Lumping PCOS in with gluten allergy is giving "shit men believe about women's health." Maybe try listening to some women before forming opinions on their reproductive health.
The symptom profile of long covid is very close to lyme disease, another disease people actually get but also many more people claim to have without evidence.
I'd like to see the overlap between long covid sufferers, IBS, lyme disease, people with a gluten allergy, PCOS etc and the level of evidence that they actually have those diseases.