Apolipoprotein E gene polymorphism, posttraumatic stress disorder, and cognitive function in older U.S. veterans: Results from the National Health and Resilience in Veterans Study.

APOE ε4 allele carriers with PTSD have substantially greater cognitive difficulties than ε4 carriers without PTSD. These results underscore the importance of assessing, monitoring, and treating PTSD in trauma-affected individuals who are at genetic risk for cognitive decline and dementia.