I don't know anything about Fibromyalgia, yet I wince when someone says it's psychosomatic. I wonder about almost any conditioned considered psychosomatic now.
I realize I'm using the term in the vernacular to mean "it's all in your head". That's how it is largely understood even though, technically, psychosomatic illness can refer to anything without a medical explanation. People communicating with the public have to understand the common usage of the term as it's being heard.
Jane Brody wrote about the concern with this label almost a decade ago (in full at the very bottom):
"When I was given a diagnosis of breast cancer in February 1999, many friends and readers wondered: 'Why did you get breast cancer? You take such good care of yourself!' . . . It seems that many people believe that if you do everything 'right', bad things won't happen. But bad things can and do happen. And they happen to the 'best' and the 'worst' of us. . . . If you're blessed with good health, you can say, 'I did it.' But if you lose your health, you know that external forces beyond your control can get in your way. Healthy people tend to act as if beneath every sick person is a healthy person trying to come out. . . .
Wasn't it Susan Sontag who pointed out that whenever the cause of an illness is mysterious, it's assumed to come from psychological problems or a moral weakness? And once science finally figures out the medical root of the illness, that assumption disappears. Will we one day have a better -- that is, more scientific -- understanding of ailments like chronic fatigue syndrome, fibromyalgia, Gulf War syndrome, multiple chemical sensitivities or any of the other current 'wastebasket' diagnoses that many medical and lay people consider psychosomatic?