BACKGROUND: Previous studies reporting cortisol hyposecretion
in chronic fatigue syndrome may have been confounded by
venepuncture, fasting and hospitalisation.
and evening salivary cortisol were obtained on consecutive
days in the first 3 days of the menstrual cycle and compared
in three samples of women taking no medication and matched for
age: 14 patients with chronic fatigue syndrome, 26 community
cases of ICD-10 current depressive episodes and 131 healthy
RESULTS: The mean evening cortisol was
significantly lower in the chronic fatigue syndrome patients
compared to controls with depression (P = 0.02) and healthy
controls (P = 0.005). Chronic fatigue syndrome patients
without psychiatric disorder had significantly lower morning
salivary cortisols compared to controls (P = 0.009).
CONCLUSION: Chronic fatigue syndrome patients display cortisol
hyposecretion in saliva as well as plasma compared to patients
with depression and healthy controls.
samples of female patients with cortisol estimated at only two
time points in the day. Cortisol secretion may be secondary to
other neurotransmitter abnormalities or other physiological or
lifestyle factors in chronic fatigue syndrome patients.
CLINICAL RELEVANCE: Chronic fatigue syndrome is biochemically
distinct from community depression.