Abbreviations: ADAS-cog; Alzheimer’s Disease Assessment Scale – cognitive; CDR-SB, Clinical Dementia Rating – Sum of Boxes; CN, control; cort., cortical; CSF, cerebrospinal fluid; MMSE, Mini-Mental State Examination; MRI, magnetic resonance imaging; PET, positron emission tomography; PTSD, posttraumatic stress disorder; SCIDS, Structured Clinical Interview for DSM; TBI, traumatic brain injury.