Basal activity of the hypothalamic-pituitary-adrenal axis in patients with the chronic fatigue syndrome (neurasthenia)

Background: Impairments in both basal activity and activation of the hypothalamic-pituitary-adrenal axis (HPA) have been reported in chronic fatigue syndrome (CFS; neurasthenia). We sought to replicate these findings and examined basal activity of the HPA in a carefully selected sample of patients with CFS. Methods: Basal activity of the HPA was assessed using salivary and urinary cortisol collection over a 24-hour period in 22 (12 male; 10 female) patients meeting criteria for CFS and appropriate controls. Results: Salivary and urinary cortisol measurement did not differ between CFS patients and controls. Conclusions: Basal activity of the HPA was not reduced in CFS patients. Reasons for the failure to replicate previous findings are discussed