Two new papers by a team of researchers demonstrate that evaluating microRNAs in blood can be used not only to diagnose mild cognitive impairment (MCI) but also, critically, to predict the conversion from MCI to dementia due to Alzheimer's disease. Moreover, the researchers uncovered microRNA candidate molecular biomarkers that associate with current Amyloid, Tau, and Neurodegeneration (A/T/N) Alzheimer's biomarkers.

The failure to diagnose Alzheimer's disease, the most common form of dementia in the elderly, at an early stage of molecular pathology is considered a major reason why treatments fail in clinical trials. Previous research to molecularly diagnose Alzheimer's disease yielded "A/T/N" central biomarkers based on the measurements of proteins, β-amyloid ("A") and tau ("T"), and "N" encompassing neurodegeneration. A/T/N can be measured in brain tissue, by in vivo brain imaging techniques, and by analysis of cerebrospinal fluid and plasma.

Medical researchers conducted the largest-ever genome-wide association study of all-cause dementia, finding substantial genetic overlap with vascular dementia.