APOD and psychiatric disorder: Remarkably, Apo D is upregulated in neural cells and CSF during aging, and in brains affected by neurodegenerative diseases characterized by cellular stress and excitotoxicity such as multiple sclerosis (MS), Spongiform encephalopathy, Parkinson’s disease (PD), Niemann–Pick disease, or Alzheimer’s disease (AD) as well as psychiatric disorders (schizophrenia and bipolar disorder) [8,21,22].