This data includes brain samples that were obtained from the Knight-ADRC at Washington University in St. Louis repository. This is a deeply phenotyped cohort, both clinically and molecularly, with longitudinal data and samples available. We included 6 samples with non-AD neurodegenerative diseases, 269 samples from AD participants and 23 samples from healthy control participants. Small RNA libraries were generating from ribosomal RNA (rRNA)-depleted total RNA using the commercially available RealSeq®-AC sRNA kit.