Traumatic brain injury and post‐traumatic stress disorder are not associated with Alzheimer's disease pathology measured with biomarkers
Michael W. Weiner, Danielle Harvey, Susan Landau, Dallas P. Veitch, Thomas C. Neylan, Jordan Grafman, Paul Aisen, Ronald C. Petersen, Clifford R. Jack, Duygu Tosun, Leslie M. Shaw, John Q. Trojanowski, Andrew J. Saykin, Jacqueline Hayes, Charles De Carli
Abstract
INTRODUCTION: Epidemiological studies report an association between traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) and clinically diagnosed Alzheimer's disease (AD). We examined the association between TBI/PTSD and biomarker-defined AD. METHODS: We identified 289 non-demented veterans with TBI and/or PTSD and controls who underwent clinical evaluation, cerebrospinal fluid (CSF) collection, magnetic resonance imaging (MRI), amyloid beta (Aβ) and tau positron emission tomography, and apolipoprotein E testing. Participants were followed for up to 5.2 years. RESULTS: Exposure groups (TBI, PTSD, and TBI + PTSD) had higher prevalence of mild cognitive impairment (MCI: P < .0001) and worse Mini-Mental State Examination scores (PTSD: P = .008; TBI & PTSD: P = .009) than controls. There were no significant differences in other cognitive scores, MRI volumes, Aβ or tau accumulation, or in most longitudinal measures. DISCUSSION: TBI and/or PTSD were not associated with elevated AD biomarkers. The poorer cognitive status of exposed veterans may be due to other comorbid pathologies.