MAPT and Alzheimer disease: Critically, PTSD significantly steepens age-related cognitive decline (Yehuda et al., 2005; Green et al., 2016), associates with greater tau accumulation (Mohamed et al., 2019), and doubles the risk of developing Alzheimer’s disease (AD) and other dementia in older individuals (Qureshi et al., 2010; Yaffe et al., 2010).