Contact: Jens Gaab, MSc.
Zürich, Switzerland
Phone: (0041) 01-6343096
Web: www.klipsy.unizh.ch/gaab
Email: jgaab@klipsy.unizh.ch
Embargoed until: March 10, 2001

MONTEREY, CA-- Nearly everyone has experienced fatigue and exhaustion. Usually this is either the consequence of stress, such as a heavy workload or strenuous workouts, or a sign of a physical disease, e.g. an infection. The fatigue experienced normally resolves after a good sleep or once the infection has been overcome.

But in some rare cases, the fatigue remains and becomes chronic. This condition - called the Chronic Fatigue Syndrome (CFS) - puzzles medical and psychological science since over 100 years, its cause and so its treatment are still not fully understood. An array of different medical and psychological hypotheses has been proposed, but none has proved to offer an exclusive explanation for this debilitating disorder.

Because most sufferers report chronic stress before the onset of CFS and stress ultimately leads to a worsening of their symptoms, research has focussed on those physiological systems, which help to handle stress, and therefore are most likely to be affected by the deteriorating effects of chronic stress. In this respect a hormone system, the so-called HPA axis with its end-hormone cortisol (Fig. 1), is of special interest. HPA axis hormones control many important bodily functions and the lack or excess of any hormone ultimately leads to ill health. The HPA axis is activated by stress and its hormones help to provide the energy to handle stress.

Several studies have shown that the activity of the HPA axis is reduced in CFS patients. "The lack of HPA axis hormones, especially CRH and cortisol, can lead to some of the symptoms experienced by CFS patients", Jens Gaab, a research scientist at the Center of Psychobiological and Psychosomatic research, University of Trier, Germany (current address: University of Zurich, Switzerland) said. "Although we know that the activity of the HPA axis is somehow reduced, we still don't know how it functions under stress and at what level this hormone axis is malfunctioning". The group of psychologists and endocrinologists set out to investigate the HPA axis in CFS patients in three stress situations, a psychological stress situation, a strenuous cycle test and a pharmacological test. The results of this study were presented at the 59th Annual Meeting of the American Psychosomatic Society, held March 7-10 in Monterey, CA. In all three tests, CFS patients had reduced ACTH responses indicative for a reduced central drive of the HPA axis. However, the cortisol responses were normal. "These results broaden our understanding of the nature the hormonal disturbances in CFS. Our results suggest that the origin of these alterations should be sought at the level of the brain", Gaab said. Interestingly, the observed alterations were more severe the longer the patient suffered from CFS. It is therefore necessary to start treatment, such as the effective cognitive behavioral therapy, as soon as possible to avoid physiological alterations secondary to the chronicity of CFS.

# # #