In particular, these new findings show that the TBI-related age-lowering effect for cognitive decline is irrespective of the various molecular pathomechanisms predominantly involved in different disorders such as AD-pathology (1-42 β-amyloid neuritic plaques and hyperphosphorylated-tau-positive neurofibrillary-tau tangles) in amnesic-MCI and AD; phosphorylated-TDP43-inclusions and Lewy Body pathology, respectively, in FTD and DLB; presumably CTE or TBI-related pathologies in Impaired; or Lewy body pathology and pigmented neuronal loss in PD. This evidence concerns the gene MAPT and Mental deterioration.