title: Gene-environment interaction of ApoE genotype and combat exposure on PTSD.
abstract: Factors determining who develops PTSD following trauma are not well understood. The €4 allele of the apolipoprotein E (apoE) gene is associated with dementia and unfavorable outcome following brain insult. PTSD is also associated with dementia. Given evidence that psychological trauma adversely affects the brain, we hypothesized that the apoE genotype moderates effects of psychological trauma on PTSD pathogenesis. To investigate the moderation of the relationship between PTSD symptoms and combat exposure, we used 172 participants with combat trauma sustained during the Vietnam War. PTSD symptoms were the dependent variable and number of combat experiences, apoE genotype, and the combat experiences × apoE genotype interaction were predictors. We also examined the outcome of a diagnosis of PTSD (n = 39) versus no PTSD diagnosis (n = 131). The combat × apoE genotype interaction was significant for both PTSD symptoms (P = .014) and PTSD diagnosis (P = .009). ApoE genotype moderates the relationship between combat exposure and PTSD symptoms. Although the pathophysiology of PTSD is not well understood, the €4 allele is related to reduced resilience of the brain to insult. Our results are consistent with the €4 allele influencing the effects of psychological trauma on the brain, thereby affecting the risk of PTSD.
authors.affiliation: Boston University, Boston, Massachusetts.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lyons
authors.forename: Margo
authors.initials: M
authors.lastname: Genderson
authors.forename: Michael D
authors.initials: MD
authors.lastname: Grant
authors.forename: Mark
authors.initials: M
authors.lastname: Logue
authors.forename: Tyler
authors.initials: T
authors.lastname: Zink
authors.forename: Ruth
authors.initials: R
authors.lastname: McKenzie
authors.forename: Carol E
authors.initials: CE
authors.lastname: Franz
authors.forename: Matthew
authors.initials: M
authors.lastname: Panizzon
authors.forename: James B
authors.initials: JB
authors.lastname: Lohr
authors.forename: Beth
authors.initials: B
authors.lastname: Jerskey
authors.forename: William S
authors.initials: WS
authors.lastname: Kremen
mesh_terms: D000375:Aging / Q000235:genetics; D001057:Apolipoproteins E / Q000235:genetics*; D003130:Combat Disorders / Q000235:genetics*; D059647:Gene-Environment Interaction; D005838:Genotype; D006306:Health Surveys; D006801:Humans; D008875:Middle Aged; D012044:Regression Analysis; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000235:genetics*; D014427:Twins / Q000235:genetics; D014744:Vietnam
chemical_list: D001057:Apolipoproteins E
keywords: GxE interaction; apoE; genetics; posttraumatic stress disorder