Abstract
Objective: Service members are frequently diagnosed with comorbid mild traumatic brain injury (mTBI) and posttraumatic stress disorder after returning from Afghanistan and Iraq. Little is known about how mTBI in the postacute and chronic phases combined with current posttraumatic stress disorder symptoms (PTS) affects performance on the Automated Neuropsychological Assessment Metrics, Version 4, Traumatic Brain Injury-Military (ANAM4) battery used by the US military. We examined postdeployment ANAM4 performance using conventional statistical methods, as well as rates of poor performance, below established cutoffs (<10th and <=2nd percentile).
Methods: A total of 868 soldiers were assessed for history of mTBI during the most recent deployment, as well as, lifetime mTBI, current PTS, and current pain-related symptoms. The ANAM4 was also administered.
Results: Soldiers with PTS and/or mTBI performed worse on ANAM4 relative to controls with those with both conditions performing worst. However, a nontrivial minority (~10%-30%) of individuals with mTBI, PTS, or both had scores that were at or below the second percentile.
Conclusion: Our results illustrate that a combination of mTBI and PTS is associated with worse ANAM4 performance than either condition alone. Furthermore, only a minority of soldiers with any, or both, of the conditions had ANAM deficits. The long-lasting impacts and unique contribution of each condition have yet to be determined.