meaning of term "Yuppie Flu"

“Yuppie Flu” was a term that originated in the USA and referred/s, for some people, to Myalgic Encephalomyelitis (M.E.) - also know as Post-Viral Fatigue Syndrome (PVFS), Chronic Fatigue Syndrome (CFS) and Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS) in the USA - but can anyone tell me who invented the expression “Yuppie Flu” and why?

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A quick Googling supplied this intriguing remark:

IT [also known as chronic fatigue syndrome (CFS)] has been dismissed as “yuppie flu”, and explained by sceptical doctors as a psychological condition that is all in the mind.
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Wow! So doctors invented it. Thanks.