Psychiatric diseases often present a progressive neurodegenerative process and, for this reason, the assessment of typical cerebrospinal fluid (CSF) or serum biomarkers of AD (tau proteins, Aβ) together with the evaluation of amyloid and tau burden in cortical areas, have been used to explore neurodegenerative indicators to understand the pathophysiologic mechanisms underlying psychiatric illness [17]. This evidence concerns the gene MAPT and psychiatric disorder.