“Most studies on PTSD in soldiers following service in war zones do not include measures of PTSD symptoms prior to deployment and thus suffer from a baseline problem,” said psychological scientist Dorthe Berntsen, Ph.D., of Aarhus University in Denmark, who worked with a team of Danish and American researchers on the study.
“Only a few studies have examined pre- to post-deployment changes in PTSD symptoms, and most only use a single before-and-after measure.”
The team addressed these issues by evaluating the symptoms of PTSD in a group of 746 Danish soldiers at five different times.
Five weeks before they were scheduled to leave for Afghanistan, the soldiers completed a battery of tests, including a PTSD inventory and a test for depression. They also completed a questionnaire about traumatic life events, including childhood experiences of family violence, physical punishment, and spousal abuse.
During their deployment, the soldiers completed questionnaires related to the direct experience of war: Perceptions of war zone stress, life-threatening war experiences, battlefield wounds, and the experience of killing an enemy.
The researchers continued to follow the soldiers after their return home to Denmark, assessing them a couple weeks after their return, two to four months after their return, and seven to eight months after their return.
Berntsen says that what she and her colleagues found challenges several widely held assumptions about the nature of PTSD.
Rather than following some sort of “typical” pattern in which symptoms emerge soon after a particularly traumatic event and persist over time, the researchers found a wide variation in the development of PTSD among the soldiers.
The vast majority of the soldiers — 84 percent — showed no PTSD symptoms or recovered quickly from mild symptoms.
The rest of the soldiers showed distinct and unexpected patterns of symptoms, according to Berntsen. About 4 percent showed evidence of “new-onset” trajectory, with symptoms starting low and showing a marked increase across the five timepoints, she noted, adding their symptoms did not appear to follow any specific traumatic event.
About 13 percent actually showed temporary improvement in symptoms during deployment, she said. These soldiers reported significant symptoms of stress prior to leaving for Afghanistan that seemed to ease in the first months of deployment, only to increase again upon their return home.
The researchers postulate that the soldiers who developed PTSD were much more likely to have suffered emotional problems and traumatic events prior to deployment. Childhood experiences of violence, especially punishment severe enough to cause bruises, cuts, burns, and broken bones, predicted the onset of PTSD in these soldiers, according to the researchers.
Those who showed symptoms of PTSD were more likely to have witnessed family violence, and to have experienced physical attacks, stalking or death threats by a spouse. They were also more likely to have past experiences that they could not, or would not, talk about, the researchers said, noting that they were less educated than the soldiers who had no PTSD symptoms.
According to Berntsen, all of these factors together suggest that army life — despite the fact that it involved combat — offered more in the way of social support and life satisfaction than these particular soldiers had at home. However, the mental health benefits of being valued and experiencing camaraderie diminished when the soldiers had to return to civilian life.
“We were surprised that stressful experiences during childhood seemed to play such a central role in discriminating the resilient versus non-resilient groups,” said Berntsen. “These results should make psychologists question prevailing assumptions about PTSD and its development.”
The study was published in Psychological Science.