Another example might be the over-diagnosis of tertiary neurosyphilis as the cause of mental illness and death, e.g. in some of my recent reading great and legi

Another example might be the over-diagnosis of tertiary neurosyphilis as the cause of mental illness and death, e.g. in some of my recent reading great and legitimate doubt was placed on that being a cause of the death of Winston Churchill's father. We now know there's a host of causes, many of which aren't (yet known to be) infectious. Although we must be careful, in one of my more interesting jobs, building a full text database for Year Book Medical Publishers (a part of Time ... -Life? Time as in the LA Times back then), the leading article for the general book for that year was on the proof of gastrointestinal ulcer being caused by a bacteria. The editor of that entry figuratively smiled about "taking away another disease from" ... whichever specialists assigned it all to stress (which of course can predispose someone to getting an infection).