Studies measuring behavior and those examining brain size and function have helped to reveal a great deal about how cognition and emotions change with age. Increasingly, however, there is a recognition that additional insight about cognitive and emotional aging can come from investigating the role of blood-based biological factors, including telomere length, gene expression, and levels of circulating compounds related to immunity, stress-responsiveness, and cardiovascular health. This talk will review recent work in this area, with an emphasis on how such factors might be used in the future to help develop individualized interventions to maintain mental wellness into old age. (#28365)