Hypothalamic-pituitary-adrenal axis activity and cognitive functioning in older adults

Objectives Inconsistent results are found in the involvement of the Hypothalamus-Pituitary-Adrenal (HPA)-axis in cognitive functioning. This study examined the association between various saliva cortisol measures and cognitive functioning in older persons with and without a depressive disorder. Methods Cross-sectional data on 328 depressed and 119 non-depressed older adults between 60-93 years from the Netherlands Study of Depression in Older adults were used. 1-h awakening cortisol, evening cortisol, diurnal slope and cortisol suppression were measured in saliva. Cognitive functioning was evaluated by episodic memory, processing speed, interference control, and working memory. Multivariate analyses were adjusted for relevant confounders. Results No significant associations between cortisol and cognitive functioning were observed in the total sample. Total cortisol secretion over the first hour after awakening and worse episodic memory, and higher cortisol levels at awakening and better working memory were significantly associated in non-depressed, but not in depressed older adults.