They evaluated CSF levels of total tau (t-Tau), phosphorylated tau (p-Tau), Aβ42, and neurofilament light chain protein (NfL) in patients with psychiatric diseases (depressive disorders, anxiety disorders, bipolar disorders, schizophrenia, and post-traumatic disorders) compared with patients with neurodegenerative disorders (probable AD, behavioural variant of frontotemporal dementia, Creutzfeldt–Jakob disease, Lewy Body disease, and probable progressive supranuclear palsy). The gene discussed is MAPT; the disease is bipolar disorder.