A LARGE Chicago-based cohort study has revealed that patterns of diurnal salivary cortisol are associated with cognitive decline in older adults, with distinct racial differences in cortisol rhythms that did not alter the strength of the cortisol-cognition association. Salivary Cortisol as a Marker of Cognitive AgingAlterations in hypothalamic-pituitary-adrenal axis activity have been implicated in cognitive aging, yet large, racially diverse studies using physiologically active salivary cortisol have remained limited. Participants provided salivary cortisol samples across the day (waking, afternoon, and bedtime) and completed cognitive assessments. Cortisol Patterns Linked to Cognitive DeclineAmong 3,895 participants (mean age 76.7 years; 64.4% women; 64.3% Black and 35.7% White), all cortisol indices were cross-sectionally associated with cognitive performance. Salivary cortisol and cognitive decline and Alzheimer disease in older adults.