Stressful and traumatic events occurring during early childhood have been consistently associated with the development of psychiatric disorders later in life. This relationship may be mediated in part by epigenetic mechanisms, such as DNA methylation, which are influenced by the early-life environment. Epigenetic patterns can have lifelong effects on gene expression and on the functioning of biological processes relevant to stress reactivity and psychopathology.

The moral injury construct has been proposed to describe the suffering some veterans experience when they engage in acts during combat that violate their beliefs about their own goodness or the goodness of the world. These experiences are labeled transgressive acts to identify them as potentially traumatic experiences distinct from the fear-based traumas associated with posttraumatic stress disorder.

Extremity injuries contribute a significant amount to the overall disability of combat-injured soldiers. Tracking patient outcomes allows military health care providers to gain a better understanding of the disability associated with various injury patterns. Only recently have orthopedic surgeons begun to collect functional outcome measures, and perhaps even more importantly, have begun to collect patient-reported outcomes. There is a growing body of evidence demonstrating the importance of a multidisciplinary approach to optimize outcomes in patients following severe extremity trauma.

Military personnel have an increased risk of developing stressrelated mental health problems after deployment to a combat zone [1]. In order to decrease the risk of developing stress-related disorders, biological vulnerability and protective factors should be identified. Neuropeptide Y (NPY) is a peptide transmitter that is associated with modulation of the stress response. Previous studies reported reduced NPY levels in the cerebrospinal fluid (CSF) of patients with posttraumatic stress disorder (PTSD) [2].