U.S. Army soldiers who return from military deployment to the Iraq war have an increased risk for mild neuropsychological compromise, including poorer memory and sustained attention performance and greater feelings of tension and confusion, according to a study in the August 2 issue of JAMA, a theme issue on violence and human rights.

Since early 2003, significant numbers of military personnel have been deployed to Iraq for Operation Iraqi Freedom (OIF). Although contemporary battlefield measures have improved war-zone survival, success in preventing fatalities has not eliminated adverse physical or mental health consequences, according to background information in the article. One major war-related health risk is often neuropsychological (i.e., cognitive and emotional) impairment. In past military conflicts, cognitive impairment figured prominently among veteran health complaints, ranking fourth among 1991 Gulf War veterans in government health registries. Because of its potential negative impact on occupational and psychosocial functioning in a predominantly young population, war-related neuropsychological impairment has significant public health implications. Yet, the consequences of war-zone deployment on neuropsychological health remain poorly understood. Knowledge gaps stem largely from a lack of predeployment health information and assessments conducted too long after war-zone exposure.

Jennifer J. Vasterling, Ph.D., of the Southeast Louisiana Veterans Health Care System and Tulane University School of Medicine, New Orleans and colleagues conducted a study to examine neuropsychological outcomes following Iraq deployment. The study included 961 male and female active-duty Army Soldiers. Deploying Army Soldiers (n = 654) were examined prior to deployment to Iraq (April-December 2003) and shortly after return (within an average of 73 days; January-May 2005) from Iraq deployment. There was also a comparison group of soldiers (n = 307) similar in military characteristics but not deploying overseas. Participants were individually administered performance-based neuropsychological tasks.

The researchers found that Iraq deployment, compared with nondeployment, was associated with mild neuropsychological compromise on tasks of sustained attention, verbal learning, and visual-spatial memory. Iraq deployment was also associated with increased negative effects on measures of confusion and tension. In contrast, deployment was associated with improved simple reaction time and no changes on other neuropsychological tasks. Deployment effects remained statistically significant after taking into account deployment-related Head injury and stress and depression symptoms. The researchers interpret their findings as the carry-over into the home environment of what was likely an adaptive brain-based survival response in the combat zone.

The researchers add that because they included only active-duty Army Soldiers in this report, their results may not be generalizable to other military branches or to National Guard and Reserve personnel activated for deployment.

“Even small declines in the ability to sustain attentional focus and learn and remember new information may reflect subtle neural dysfunction, lead to problems in day-to-day life, and negatively affect performance in high-pressure contexts such as subsequent war-zone participation,” the authors write.

Neuropsychological Changes Following Military Service in Iraq - Case Proven, But What Is the Significance?
In an accompanying editorial, Matthew Hotopf, Ph.D., of the Institute of Psychiatry and Simon Wessely, F.Med.Sci., of the King’s Centre for Military Health Research, London, discuss the findings of Vasterling and colleagues.

“Whether veterans should be concerned about the findings of Vasterling et al depends on the answers to several other questions. First, are the reported effects clinically significant? The authors emphasize that the neuropsychological changes are ‘mild’ and ‘subtle.’ Although data on the distribution of test performances are not presented, the implication is that the effect represents a minor change for the population as a whole rather than significant impairments in a few.”

“Another possibility is that the effect is due to the persistence on return home of some of the psychological adaptations required during deployment. The term battlemind captures the way in which deployed military personnel develop ways of adapting that are appropriate and helpful when vigilance is required, decisions have to be taken quickly, targeted aggression is appropriate, and emotional control is essential. Many returning veterans report difficulties switching from these normal responses to the responses required at home.”

“The final question for concerned veterans is whether the changes will persist. Given the lack of prior literature on neuropsychological functioning in populations of returning veterans, the planned follow-up of this cohort, with further rigorous neuropsychological testing and clinical monitoring, will be most welcome and certainly most important,” the authors conclude.

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