Effect of age and sex on cortisol secretion in depressives and normals.

The mean 24-hour plasma level of cortisol with plasma sampling every 20-30 minutes was determined in 32 normal women aged 12-73, 40 normal men aged 10-55, 21 depressed women aged 20-61, and 11 depressed men aged 22-66. The mean levels of cortisol were higher in the group of depressives compared with the controls. Cortisol levels showed a significant linear correlation with age in normal women but not in normal men. Both depressed women and men had a significant linear increase of cortisol levels with age. The finding that age substantially contributes to increased levels of cortisol calls for cautious interpretation of any data concerning that hormone when the variable of age is not adequately controlled. Furthermore, aging and depression may have some underlying mechanisms whose elucidation may contribute to the understanding of the pathophysiology of vulnerability to affective disorders.