This fascinating article was first published in the Age.
THE stress of combat can change the way soldiers’ brains are wired, resulting in a reduced cognitive function, such as the ability to focus on tasks.
Published in the journal PNAS this week, the results showed that exposure to ”combat stress” – including armed combat, enemy fire, combat patrols and improvised explosive device blasts – affected the structural integrity of the midbrain and its ability to interact with the pre-frontal cortex.
Julie Krans, a postdoctoral research fellow at the University of New South Wales, said the study findings illustrated that exposure to highly stressful situations wasn’t just expressed via post-traumatic stress disorder.
”[The soldiers] may not be suffering a clinical disorder but they are still impairing their daily life,” she said.
Dr Krans said more attention should be given to the effect of combat stress on cognitive functions such as attention, memory, problem-solving and decision-making.
The research studied a group of NATO soldiers before they were deployed to Afghanistan and compared the results with tests taken six weeks after the troops returned from a four-month stint.
The researchers, from Dutch institutions including the University of Amsterdam and the Ministry of Defence, used a range of measures including functional MRI to compare brain changes tied to ”executive functions”, which rely on attention and working memory for planning and decision-making.
The 33 soldiers who participated were selected from the NATO International Security Assistance Force peacekeeping operation. The researchers used 26 soldiers, who had never been deployed to a combat zone, as a control group.
The results showed reduced activity in the midbrain six weeks after exposure to combat stress.
Upon follow-up 18 months later, changes to the connections between the midbrain and the pre-frontal cortex remained, suggesting combat stress may have long-lasting effects on cognitive brain circuitry.
Sandy McFarlane, director of the Centre for Traumatic Stress Studies at Adelaide University, said the study demonstrated the need for regular time away from combat zones to allow soldiers’ brains to ”re-set”. Professor McFarlane said the findings were consistent with similar studies, including an American one that found working memory was adversely affected by exposure to combat.
”[That study showed] this slowly corrects itself with time, except in those who go on to get post-traumatic stress disorder.”
This article was first published by The Age, 4 September 2012.