The wars in Iraq and Afghanistan are coming to an end, but, as family members of service men and women know, soldiers don\u2019t always return home unchanged and unharmed, even when there is not a scratch to be seen. A recent study took a look at how receiving a traumatic brain injury (TBI) affects a soldier\u2019s risk for developing post-traumatic stress disorder (PTSD) later on. In a study by researchers from the University of California, San Diego School of Medicine and the Veterans Affairs San Diego Healthcare System examined 1,648 male and female members of the Marines and Navy who were on active duty. By the end of their study the researchers found that soldiers who sustained a TBI while they were deployed to Afghanistan or Iraq were at higher risk for developing PTSD in the future. In fact, receiving a TBI was the strongest predictor of all for later PTSD. The researchers assessed the soldiers one month prior to a seven month tour of duty in either Afghanistan or Iraq. The servicemen and women were assessed again seven days after coming home at the end of deployment, and then at three months and again at six months post deployment. Assessments were made using the widely accepted Clinician-Administered PTSD Scale. As part of their assessment soldiers were asked if they had sustained any head injuries before joining the military, as well as whether they had suffered any sort of head trauma during their active duty service. Here is what was reported: \t56.8 percent said they had sustained a TBI pre-deployment \t19.8 percent said they had sustained a TBI during their deployment. Of those who were injured during their tour of duty: \t87.2 percent sustained injuries that could be categorized as mild \t117 Marines went unconscious as a result of TBI \t111 of the 117 who fell unconscious spent less than half an hour unconscious. In addition to making a record of TBI history and any prior PTSD symptom history the researchers also inquired about combat experiences during deployment. Soldiers were scored or rated for combat intensity on a scale that went from Never to Every Day. As a result researchers could consider the impact of a previous TBI, a TBI sustained while in combat, previous PTSD symptoms and the degree of combat intensity experienced as risk factors for subsequent PTSD. There was a distinct correlation between prior head trauma plus combat intensity and the severity of subsequent PTSD symptoms. The higher those first two scores, the more intense the symptoms of future PTSD. In cases with no PTSD symptoms pre-deployment coupled with a low score on combat intensity there was a less than one percent lowering of risk for later PTSD. At the same time, each increase in prior symptoms or combat intensity was reflected in a one to two percent increase in later PTSD risk. PTSD is a serious mental health condition in which a person experiences painfully heightened stress responses. Apart from all the symptoms the come with PTSD which themselves can be debilitating, the condition is also associated with a number of other comorbid problems such as suicidal ideation, depression, substance abuse and trouble thinking clearly. The Study summarized that having PTSD symptoms before being deployed is a significant risk factor for future PTSD. It also highlighted that high intensity combat conditions bring a significant risk factor for developing future PTSD. Sustaining a TBI during deployment is the strongest risk factor for struggling with PTSD later on The study was published in the professional medical journal JAMA Psychiatry.