https://pubmed.ncbi.nlm.nih.gov/3063394/
But many cases of "long covid" appear to be psychosomatic.
https://jamanetwork.com/journals/jamainternalmedicine/fullar...
And then, just as you say, there's "long covid", which is a large number of people who have very generic ailments, and if you start digging into the numbers, you realize it's all self-reported bullshit, where a good chunk of the sufferers haven't even been diagnosed with covid in the first place! Their symptoms match depression very well, though.
It's extremely frustrating watching people like my friend getting ridiculed for having an imaginary disease. She doesn't. And at the same time it's even more frustrating watching a relatively huge number of psychosomatic hypochondriacs getting all the attention and using up the wrong kind of healthcare resources, just because a lot of people are using long covid for generating fear porn and want it to be worse than it is.
Highlighted on the page: "As of July 2021, 'long COVID,' also known as post-COVID conditions, can be considered a disability under the Americans with Disabilities Act (ADA). "
https://www.washingtonpost.com/politics/biden-ada-long-covid...
Medically it just seems to fall outside the flowcharts of modern medicine where an "easy fix" or "procedure" is not prescribed. Going outside of the "acceptable medicine" of what insurance will cover is practically a unicorn event. So you'll see a lot of doctors just calling it "anxiety." Functionally, Long Haul Covid has become a huge cash bonus to medicine as sufferers get referred (passed around) from specialist to specialist for more testing and diagnostics that nearly always comes up as "normal."
About the only good news about this situation is very likely once they really get the studies done (and they're going to have to do it, because there will be millions of people suffering from this) they are likely also going to find how to help people with chronic fatigue syndrome (CFS) since all the long hauling symptoms appear to over lap. CFS sufferers already have had the feeling of being ignored/ridiculed by medicine for decades.