A recent example of the importance of mitochondrial function in neurons is the report of homozygous missense variants in pitrilysin metallopeptidase 1 (PITRM1) causing a neurological syndrome with progressive cerebellar dysfunction and atrophy, with psychiatric manifestations including obsessive behavior, psychosis, and cognitive decline (Alikhani et al. 2011a, b; Brunetti et al. 2016). This evidence concerns the gene PITRM1 and Mental deterioration.