Effects of Military Deployment on Cognitive Functioning

Authors
Vincent, A. S. Roebuck-Spencer, T. Lopez, M. S. Twillie, D. A. Logan, B. W. Grate, S. J. Friedl, K. E. Schlegel, R. E. Gilliland, K.
Publication year
2012
Citation Title
Effects of military deployment on cognitive functioning.
Journal Name
Military Medicine
Journal Volume
177
Issue Number
3
Page Numbers
248-255
DOI
10.7205/MILMED-D-11-00156
Summary
Active Duty Service members without traumatic brain injuries (TBI) were evaluated before and following deployment to Iraq or Afghanistan to evaluate the possibility of an association between deployment and measurable changes in cognitive functioning. Data gathered upon the Service members’ return from deployment suggest that the general environmental stressors of deployment had minimal to no lasting effect on cognition.
Key Findings
There were minimal differences in Service members' cognitive functioning performance before and following deployment.
Overall cognitive functioning performance improved from pre- to post-deployment. Specifically, improvement was observed on five of the seven tests of cognitive functioning.
A very small percentage (less than 3%) of this sample showed meaningful decline in cognitive functioning following deployment.
Implications for Program Leaders
Provide professionals who work with military families improved training on warning signs that suggest decline in cognitive functioning
Host support groups for military spouses or partners in order to have a place where they can share their experiences and exchange resources related to Service members who have cognitive impairments
Develop post-deployment workshops for Service members that enhance education, activities, and curriculum related to coping behaviors and dealing with TBI symptoms
Implications for Policy Makers
Encourage the development and continuation of programs that promote resilience in Service members, their partners, and children
Recommend training for community professionals to educate them about unique factors, including TBIs, that contribute to marital strain for military couples
Recommend partnerships among military-based and community-based programs to help military families feel more comfortable participating in services and activities that are not on installations
Methods
Data were obtained from the Automated Neuropsychological Assessment Metrics (ANAM), which contains Service members' pre- and post-deployment neurocognitive test information.
Service members who self-reported a previous brain injury or TBI-related symptoms, had incomplete or inconsistent data, and testing data with less than a 90 day time interval were excluded from the sample.
Data were comprised of results from tests that assessed variables such as mood, sleepiness, processing speed, motor reaction time, and memory.
Participants
Participants consisted of 8,002 Active Duty Service Members; among the sample, 91% were males and average age was 26.5 years (SD = 6.4).
Racial composition, Service members' rank, and service branches were not specified.
The average time between pre-deployment and post-deployment testing was 396 days (SD = 78, range from 90 to 489 days).
Limitations
No data were provided as to the average scores of the ANAM neurocognitive tests, so it is difficult to determine if this sample's scores are low, average, or high compared to other samples.
Without follow-up the course of cognitive functioning over time is unknown.
Using Service members' self-report of the presence of a medical condition may have lead to incorrect labeling of their symptoms, which was not accounted for in interpretation of the findings.
Avenues for Future Research
Examine whether there is increased risk for cognitive decline in Service members with mild TBI during and after deployment
Gather data from Service members' medical providers, spouses, and other family members about their cognitive functioning before and after deployment
Utilize a longitudinal method to investigate cognitive functioning both during and immediately after deployment, as well as longer-term after homecoming
Design Rating
2 Stars - There are some flaws in the study design or research sample, but those flaws do not significantly threaten the ability to make conclusions based on the data.
Methods Rating
2 Stars - There are no significant biases or deficits in the way the variables in the study are defined or measures and conclusions are appropriately drawn from the analyses performed.
Limitations Rating
2 Stars - There are a few factors that limit the ability to extend the results to an entire population, but the results can be extended to most of the population.
Focus
Multiple Branches
Target Population
Population Focus
Military Component
Abstract
Military deployment poses many risks for cognitive functioning. When deployed individuals are compared to a nondeployed control group, there is some evidence that deployment may be associated with declines in cognitive functioning. The current study examined cognitive performance before and following deployment in a large sample of active duty military personnel (N = 8,002) who reported no traumatic brain injury (TBI). Cognition was assessed using the Automated Neuropsychological Assessment Metrics version 4 TBI Military (ANAM4 TBI-MIL) battery, a computer-based battery of tests measuring attention, processing speed, and general cognitive efficiency. Pre and postdeployment scores were compared using repeated measures analyses. Although statistically significant differences were observed for all tests (with 5 of 7 tests demonstrating performance improvement), effect sizes were very small for all but 1 test, indicating that performance differences had minimal clinical significance. Likewise, determination of change for individuals using reliable change indices revealed that a very small percentage (3%) of this presumed healthy sample showed meaningful decline in cognition following deployment. Analyses indicated that despite risks for cognitive decline while in theater, deployment had minimal to no lasting effect on cognition as measured by ANAM4 TBI-Mil upon return from deployment.
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