This study explores whether spironolactone, a medicine used for blood pressure, is safe for older African Americans with memory problems, like mild cognitive impairment (MCI). Spironolactone works by blocking a hormone called aldosterone that affects blood pressure and the brain's blood vessels. Participants will take spironolactone or a placebo (a pill with no medicine) for one year and visit the study center 4 to 5 times. The study checks if spironolactone helps memory and thinking by using cognitive tests (tests that measure how well your brain works) and an ultrasound, which uses sound waves to measure the stiffness of blood vessels in your neck.

• Participants will be in the study for one year, taking either spironolactone or a placebo.
• There will be 4 to 5 visits to the study center.
• Researchers will monitor for side effects and changes in memory and thinking.

Eligible participants are African Americans who meet certain memory and blood pressure criteria. Some people, such as those with recent strokes or certain medical conditions, cannot join. This study could help find new uses for spironolactone and improve brain health as we age.