DORA and LP in Alzheimer's Disease Biomarkers

This study is testing whether a sleep medication called lemborexant (a type of medication called a DORA) can reduce early Alzheimer's disease markers in the brain and spinal fluid. Researchers believe improving deep sleep may help clear harmful proteins linked to Alzheimer's. **You may be eligible if...** - You are 65 years or older - You have no signs of memory problems or dementia (normal cognitive function) - You are willing to undergo study procedures including possible spinal fluid collection **You may NOT be eligible if...** - You have restless legs syndrome, narcolepsy, or sleep behavior disorders - You have untreated or poorly treated sleep apnea - You have had a stroke, kidney disease, liver disease, or HIV - You have a history of substance or alcohol abuse in the past 6 months - You drink alcohol regularly (3+ days per week) near bedtime - You are pregnant or breastfeeding - You are currently taking medications that interact with the study drug and cannot stop them Talk to your doctor to see if this trial is right for you.