Effects of age on spontaneous cortisolaemia of normal volunteers and depressed patients

The aim of this study was to characterize the relationships between age and endogenous cortisol secretion in healthy controls and in major depressed patients between 18 and 58 years of age. Toward this end, the authors measured morning basal plasma cortisol secretion every 30 min from 0900 h until 1100 h and computed the integrated morning cortisol secretion in 80 normal controls and 118 major depressed patients. A significant negative correlation between age and plasma morning cortisol was found in normal volunteers but not in major depressives. The observed decrease in cortisol secretion with age in normal controls older than 35 years does not occur in major depressives. The middle age (± 35 years) appears to be an important turning point in hypothalamo-pituitary-adrenal (HPA)-axis function of normal persons vs. major depressives.