TP53 and major depressive disorder: These miRNAs are predicted to have functional roles in regulating pluripotency of stem cells, FoxO, Ras, Pi3K‐Akt, MAPK, mTOR, TGF‐β, p53, and AMPK signaling pathways as well as long‐term depression, suggesting the middle‐aged and elderly group demonstrate increased expression of nutrient‐sensing pathways and onset of long‐term depression when compared to the nonagenarian cohort (Table S7).