Enhanced Negative HPA Axis Feedback in CFS
Recently a study was conducted in the UK that showed a problem with an overactive negative hpa axis feedback loop in chronic 
fatigue patients. The UK researchers used dexamethasone to observe changes to the feedback loop over 6 hours. The drug dexamethasone is a glucocorticoid similar to cortisol. If a person takes dexamethasone their body should make less ACTH (a hormone that causes the release of cortisol). In normal people the amount of ACTH and cortisol should fall to a certain range.
The CFS patients in the study had lower than normal levels of cortisol and ATCH after the dexamethasone test.
This means that for some reason the bodies feedback mechanisms that keep cortisol levels in check, are overactive, and cause cortisol levels to become abnormally low. This may lead to symptoms of CFS in some people.
Low levels of cortisol were found in some patients, but not all. The lower levels of cortisol were only found in CFS patients that were also depressed.
This could be very helpful news those that do fit in this group. As there is more evidence that there are biological abnormalities in CFS. There still is no information about what the malfunctioning feedback mechanism may be. And the study group was small. But this gives a direction for other researchers to persue further. Hopefully a larger group will be studied and they may pinpoint the mechanisms that are causing problems with this negative feedback loop.
