CFS artilce

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NEW YORK (Reuters Health) Aug 31 - Chronic fatigue syndrome (CFS) and

depression have distinct neurobiological properties, researchers in

Canada report, suggesting that the two conditions have unique

etiologies. Unlike depression, CFS is characterized by decreased skin

conductance levels but increased peripheral skin temperature.

" Electrodermal analysis may represent a useful tool in the process of

differential diagnosis of CFS and depression, " Dr. Hannah

Pazderka- and her colleagues suggest in their paper in the

August issue of the International Journal of Psychophysiology.

The considerable overlap between the symptoms of CFS and of depression

has led many to question whether CFS is really a different condition,

or if it is actually a manifestation of depression. Dr.

Pazderka- and her team at the University of Alberta, Edmonton,

theorized that psychophysiological indicators could be used to

discriminate between the two.

They obtained their data from 36 nondepressed subjects with CFS, 19

with depression and 33 normal, healthy controls. Bilateral

electrodermal activity was recorded using electrodes placed on the

third and fourth fingers of each hand, while skin temperature was

measured with temperature transducers placed on the fifth finger.

Skin temperature levels differed significantly between the CFS group

(mean 34.1 degrees C) versus the depression group (31.1 degrees) and

the control group (30.1 degrees).

Mean tonic skin conductance levels were significantly lower in the CFS

group compared with the control group and the depression group. The

depression group and the control group did not differ significantly

from each other with regard to this measurement, however.

" Both these findings point to down-regulation of autonomic sympathetic

tone, as the sympathetic system is responsible for vasoconstriction in

the periphery, " Dr. Pazderka- and her associates conclude.

Int J Psychophysiol 2004;53:171-182.