Combat Stress in Afghanistan Could Alter Soldiers’ Long-Term Neural Makeup
Some soldiers who serve in Afghanistan or other war-torn countries return home with visible injuries: concussions, broken bones or amputated limbs. Many others, though, suffer from injuries we can’t visibly see. The daily strain of being exposed to armed combat, enemy fire and unpredictable explosions can lead to a range of behavioral symptoms, including fatigue, slower reaction times and a difficulty in connecting to one’s immediate surroundings.
A new study of soldiers returning home from Afghanistan, published today online in the Proceedings of the National Academy of Sciences, hints at the underlying cause for these behavioral changes. Researchers from the Netherlands and elsewhere used neurological exams and MRI scanning techniques to examine 33 soldiers before and after a four-month deployment in NATO’s International Security Assistance Force, and compared them to a control group of 26 soldiers who were never deployed.
The results were sobering—and indicate that a relatively short period of combat stress can alter an individual’s neurological circuitry for a long time.
As compared to the pre-deployment baseline tests and the control group, the returning soldiers’ brains showed distinct differences, despite the fact than none had suffered physical injuries and only one had exhibited enough symptoms to be clinically diagnosed with post-traumatic stress disorder. A pair of different techniques using MRI—diffusion tensor imaging, which measures the diffusion of water in the brain, indicating tissue density, and fMRI, which measures blood flow in various parts of the brain—revealed that the soldiers’ midbrains had reduced tissue integrity and showed less neuron activity during a working memory task.