NEFL and Mental deterioration: New blood-based biomarker tests such as p-tau 181, p-tau 217, Aβ 42 : 40 ratio, neurofilament light (NfL), and glial fibrillary acidic protein (GFAP), should provide pivotal, complementary, molecular-level data to support or refute the estimation of improvement (cognitive and pathophysiological), and may ultimately offer new insight into the optimal protocols for preventing and reversing cognitive decline.