All three/two/one are appalling, crippling, terrible syndromes which ruin people's lives. They are fairly common. You almost certainly know one or two sufferers. The suffering is made worse by the fact that most people believe that they're psychosomatic, which is a polite word for 'imaginary'.

I don't think that it's useful to treat imaginary the same as psychosomatic. Quite a lot of illnesses have psychosomatic parts and react to treatment on that level is the treatment is done right. Mostly it's difficult to get good treatment but that is no reason to equate it to imaginary suffering.

Up or downregulating hormones is something that the brain can do.