OBJECTIVE: The authors measured 24_hour urinary free cortisol in a group of well_characterized patients with chronic fatigue syndrome.
METHOD: They obtained 24_hour urine collections from 121 consecutive
clinic patients with chronic fatigue syndrome and 64 comparison subjects without the syndrome.
RESULTS: Urinary free cortisol was significantly lower in the subjects
with chronic fatigue syndrome regardless of the presence or absence of
current or past comorbid psychiatric illness. Lower levels of urinary
free cortisol were not related to medication use, sleep disturbance, or
CONCLUSIONS: There is mild hypocortisolism in chronic fatigue syndrome.
Whether a primary feature or secondary to other factors,hypocortisolism may be one factor contributing to the symptoms of chronic fatigue syndrome.
Am J Psychiatry 2001 Apr 1;158(4):641-643