Alzheimer's disease (AD) progression varies based on the presence of tau and amyloid-beta (Aβ) proteins in the brain. Patients with high levels of both tau and Aβ experience rapid memory decline, while those with high Aβ but low tau show a slower progression. The research emphasizes that tau levels are crucial for diagnosing and managing AD effectively. This insight could lead to more personalized treatment strategies as biomarker technology advances.