Previous studies have suggested that combat veterans who develop post-traumatic stress disorder (PTSD) are at three to four times the risk for future dementia, which may be attributed to genetic risk factors. In a recent study published in Nature Mental Health , researchers identify shared genetic loci among military veterans with late-onset Alzheimer’s disease and related dementias (ADRD). Study: No replication of Alzheimer’s disease genetics as a moderator of the association between combat exposure and PTSD risk in 138,592 combat veterans.
Image Credit: Prostock-studio / Shutterstock.com Specific variants of APOE , the gene that codes for apolipoprotein E (APOE), confer a substantial risk for Alzheimer’s disease (AD). For example, two copies of the E4 variant are associated with a 14-fold or more increased risk of AD among those of European ancestry and a three—to four-fold increased risk among those of African ancestry.
The APOE4 ε4 variant adversely affects the clearance of abnormal amyloid beta (Aβ) in the brain, which is the pathognomonic feature of AD. Other pathways affected by this gene include neuroplasticity, neuroinflammation, neurogenesis in the hippocampus, and glucose metabolism. The APOE4 variant also increases the risk of cardiovascular and metabolic disease.
Previous studies have reported an increased risk of dementia in APOE ε4 carriers who develop PTSD. These individuals also exhibit a more significant decline in cognitive performance with PTSD..
