With the rise of the Interwebs FDD is becoming more and more common. Fad Diagnosis Disorder involves the extraction of cash from the wallets of people who are suffering and, understandably, are looking for a fix.
Here's a doctor's explanation -
Recipe for a New Fad Disease
Pick any symptoms—the more common the better.
Pick any disease—real or invented. (Real diseases have more potential for confusion because their existence can't be denied.)
Assign lots of symptoms to the disease.
Say that millions of undiagnosed people suffer from it.
Pick a few treatments. Including supplements will enable health food stores and chiropractors to get in on the action.
Promote your theories through books and talk shows.
Don't compete with other fad diseases. Say that yours predisposes people to the rest or vice versa.
Claim that the medical establishment, the drug companies, and the chemical industry are against you.
State that the medical profession is afraid of your competition or trying to protect its turf.
If challenged to prove your claims, say that you lack the money for research, that you are too busy getting sick people well, and that your clinical results speak for themselves.