A COMPARISON OF SALIVARY CORTISOL IN CHRONIC-FATIGUE-SYNDROME, COMMUNITY DEPRESSION AND HEALTHY CONTROLS

Background: Previous studies reporting cortisol hyposecretion in chron ic fatigue syndrome may have been confounded by venepuncture, fasting and hospitalisation. Methods: Morning and evening salivary cortisol we re obtained on consecutive days in the first 3 days of the menstrual c ycle and compared in three samples of women taking no medication and m atched for age: 14 patients with chronic fatigue syndrome, 26 communit y cases of ICD-10 current depressive episodes and 131 healthy communit y controls. Results: The mean evening cortisol was significantly lower in the chronic fatigue syndrome patients compared to controls with de pression (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). Conclusi on: Chronic fatigue syndrome patients display cortisol hyposecretion i n saliva as well as plasma compared to patients with depression and he althy controls. Limitations: Small samples of female patients with cor tisol estimated at only two time points in the day. Cortisol secretion may be secondary to other neurotransmitter abnormalities or other phy siological or lifestyle factors in chronic fatigue syndrome patients. Clinical relevance: Chronic fatigue syndrome is biochemically distinct from community depression. (C) 1998 Elsevier Science B.V.