I've just had my test results back and both my cortisol and DHEA are way way low! I've got new pills to take to boost my adrenal gland.

Has anyone else had this and did their health improve with treatment (esp the fibro)?

Can't really help you, as I am in exactly the same boat! My results came back a few days ago, low cortisol and DHEA. Haven't embarked on a programme to try and correct this yet as I'm not 100% convinced.....yet.

Would also like to hear if anyone else has any experiences relating to this and CFS.

I have ascertained from my readings, low cortisol levels are one of the diagnosing tools of CFS/ME. The same symptoms & high cortisol levels would indicate a diagnosis of major depression. The same symptoms & normal cortisol levels would indicate a diagnosis of something else. I don't know anything about correcting cortisol levels, it is my understanding that adrenal malfunction is a piece of the puzzle, not the whole problem.