Abstract
Background The apolipoprotein E (APOE) ε4 allele has been implicated in a range of neuropsychiatric conditions. The present research examined if the ε4 allele of the APOE gene moderated the effect of combat exposure on posttraumatic stress disorder (PTSD) among Iraq/Afghanistan-era veterans. Method Participants included 765 non-Hispanic White (NHW) and 859 non-Hispanic Black (NHB) Iraq/Afghanistan-era veterans. A structured interview established psychiatric diagnoses. Combat exposure and PTSD symptom severity were assessed via self-report. Results The most common lifetime diagnoses were depression (39.2%), PTSD (38.4%), and alcohol dependence (24.38%). After correcting for multiple comparisons, no significant effects were observed on any of the outcomes among the NHW sample; however, within the NHB sample, significant gene × environment (G × E) interactions were observed for lifetime PTSD (P =.0029) and PTSD symptom severity (P =.0009). In each case, the APOE ε4 allele had no effect on the outcomes when combat exposure was low; however, when combat exposure was high, an additive effect was observed such that ε4 homozygotes exposed to high levels of combat reported the highest rates of PTSD (92%) and the worst symptom severity scores on the Davidson Trauma Scale (M = 79.5). Conclusions Although preliminary, these findings suggest that the APOE ε4 allele, in conjunction with exposure to high levels of combat exposure, may increase veterans' risk for developing PTSD.
Original language | English (US) |
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Pages (from-to) | 307-315 |
Number of pages | 9 |
Journal | Depression and Anxiety |
Volume | 32 |
Issue number | 5 |
DOIs | |
State | Published - May 1 2015 |
Externally published | Yes |
Keywords
- APOE
- PTSD
- comorbidity
- depression
- genetic
- veteran
ASJC Scopus subject areas
- Clinical Psychology
- Psychiatry and Mental health