Dysregulated mitochondria-focused genes in US military service members with PTSD

Background: Posttraumatic Stress Disorder (PTSD) is a complex mental disorder with functional and structural changes in the brain that may result from mitochondria-centered responses to harmful stresses. PTSD is an ongoing issue in the military. However, at present, there is no biological tool for PTSD diagnosis. Diagnosis for PTSD is established on the basis of clinical history and mental status examination, using a clinically structured interview based on a symptom checklist or patient self-report. It is often under-diagnosis. The clinical assessment would benefit substantially from a more objective means to identify PTSD patients. Here, we present evidence that there are significant differences of expression profiles of mitochondria-focused gene in the blood between PTSD and non-PTSD control US military service members. Methods: Using a mitochondria-focused gene cDNA array, we examined the expression profiles of 1170 mitochondria-focused genes across samples from subjects with (n=28) or without (n=31) probable PTSD who were active duty US Army Special Operations soldiers deployed to the Iraq and/or Afghanistan war and who were evaluated for probable current PTSD using the PTSD Checklist (PCL). Using the analytical approach of unsupervised pattern recognition with algorithmic basis of clustering, 10 clusters or pathways were revealed from the mitochondria-focused gene microarray data. Results: Significance tests demonstrated different expression levels in 26 genes between PTSD and non-PTSD controls. A relationship analysis found that among the 26 genes, the expression levels of five genes were significantly correlated with the total PCL score in the PTSD subjects. Conclusion: The expression of mitochondria-focused gene fingerprints and dysregulated genes in the blood of PTSD patients warrants a large size study to determine their clinical utility in military population

PTSD symptom severity and sensitivity to blood, injury, and mutilation in U.S. army special operations soldiers

Sensitivity to blood, injury, and mutilation (SBIM) may increase risk for posttraumatic stress disorder (PTSD), given that traumatic events often involve actual or perceived threat of bodily harm to oneself and/or others, including exposure to blood and other mutilation-related stimuli. A self-report questionnaire was administered to male, active duty, U.S. Army Special Operations Command soldiers who had deployed to Iraq and Afghanistan (n =694 males). We first used exploratory factor analysis to examine whether the 30-item Mutilation Questionnaire (Klorman et al., 1974) comprised a unitary measure of SBIM, finding that 10 of the items form a cohesive SBIM factor. Summed, those 10 SBIM items had a significant bivariate correlation with PTSD symptom severity. In a multiple regression analysis that included demographic characteristics and lifetime trauma exposure, SBIM was positively associated with PTSD symptom severity. Other significant multivariate predictors were high lifetime trauma exposure and junior enlisted rank. When trait neuroticism was added to the model to test the robustness of these findings, the association of SBIM with PTSD symptom severity remained significant. The results suggest that SBIM may be a risk factor for PTSD in male soldiers. Further research is warranted to improve measurement and understanding of SBIM