A large number of women veterans have developed posttraumatic stress disorder (PTSD) as a result of exposure to interpersonal, combat, or combat-support related traumatic events during their time in the service. However, the majority of women veterans will not experience any significant mental health problems despite exposure to potentially traumatic events. Factors that distinguish women in these two distinct trajectories are not well-understood. The present proposal aims to begin to address this issue by identifying objective biomarkers of PTSD and resilience in women veterans using neuroimaging and genotyping. To that end, women veterans with and without PTSD will be asked to complete diagnostic interviews, undergo a magnetoencephalography (MEG) scan, and provide a blood sample for genetic analyses. MEG is a simple, brief, non-invasive neuroimaging tool that permits robust and accurate classification of various conditions by evaluating synchronous neural interactions (SNI). Prior research has identified MEG-SNI biomarkers for schizophrenia, alcohol dependence, Alzheimer's disease, Sjogren's syndrome, multiple sclerosis, and PTSD in male veterans, among others. The present proposal will seek to extend the latter findings to women in order to (1) validate the previously identified SNI biomarker of PTSD or establish an SNI biomarker specific to women and (2) evaluate neural differences associated with different trauma types (e.g., combat vs. sexual assault) in women veterans. In addition, blood will be analyzed to determine Apolipoprotein E (apoE) genotype of veteran women with and without PTSD. The importance of genetic influences on psychological outcomes following exposure to traumatic events has long been regarded as central to understanding why some people are resilient in the face of trauma and others develop PTSD or related mental health problems. Most such studies have focused on only a few genes and the findings have been inconsistent. ApoE, which has been largely overlooked in the study of PTSD, has been implicated in numerous functions including neural development, regeneration, and plasticity and has been associated with several neuropsychiatric disorders. Only one published study has examined the association between apoE and PTSD. Preliminary studies included in this proposal further support an association between apoE and PTSD in male veterans and suggest that certain characteristics of apoE may reduce the severity of PTSD symptoms. Furthermore, this effect appears to be accounted for by effects on neural synchrony. This proposal will seek to extend this literature and clarify the associations between apoE, PTSD, and neural functioning in women veterans. The results of this study will improve knowledge on the pathophysiology of PTSD and resilience. Most important, identification of an objective indicator of PTSD will ultimately enhance veterans' health and treatment by improving diagnoses and providing an objective biologically-based indicator to track treatment outcomes for those suffering from this devastating illness.
PTSD is one of the most pressing issues the nation's women veterans and the VA face. Women veterans have participated in recent conflicts at unprecedented rates and are at high risk of exposure to interpersonal, combat, and combat support-related traumatic events. Yet, many women veterans are resilient and will not develop any significant mental health problems despite trauma exposure. Identification of objective biomarkers of PTSD and resilience in women veterans is vital not only for understanding the pathophysiology of these distinct trajectories following exposure to trauma but also for potentially identifying those at risk for PTSD. The overarching goals of this multi-method study are to 1) extend our previous neuroimaging research on male veterans to female veterans with and without PTSD to identify brain-based biomarkers of PTSD and resilience and 2) evaluate the relationship between specific genetic polymorphisms, mental health status, and neural functioning in women veterans.
