26,27 TBI and PTSD co-occurring Historically, some controversy has existed regarding whether PTSD and TBI can coexist; however, more recent, work in this area suggests that they can. If the injury and psychiatrically traumatic event are co-occurring, those with a less severe AOC seem to be at greater risk for developing PTSD. As noted above, Inhibitors,research,lifescience,medical complaints are frequently shared between those with TBI and/or PTSD (eg, poor attention);

thereby complicating differential diagnosis. This particularly true for those with mild TBI, and/or repeated exposure to trauma (physical, psychological). For example, work by Brenner et al,28 suggested that in retuning soldiers with histories of physical injury, mild TBI and PTSD were independently associated with self-reported memory problems. Moreover, a combination of the conditions was found to be more strongly associated with memory problems than either condition alone. In looking at post-traumatic symptoms (PTS) and postconcussive symptoms (PCS) (eg, slowed

thinking, poor concentration) among returned Operation Inhibitors,research,lifescience,medical Enduring Freedom/Operation Iraqi Freedom (ORF/OTF) Veterans, Benge and colleagues29 found Inhibitors,research,lifescience,medical that PTS and PTC were not independent variables, thereby suggesting that, incorrect, attribution of PCS to history of TBI may preclude referral to appropriate treatment. Challenges associated with symptom attribution are at least, in part related to the fact that common areas of the brain are implicated in both conditions (Table III shows brain regions and functions often discussed in relationship to PTSD and/or TBI).

Whereas neuroimaging and neuropsychological findings have contributed to the understanding of each of these Inhibitors,research,lifescience,medical conditions, and are frequently employed in clinical practice, guidance regarding how to best use these diagnostics tools to inform practice with these populations is limited. Moreover, contextual and/or person-specific Inhibitors,research,lifescience,medical thing factors such as deployment to a combat, zone, effort (eg, fatigue, distraction secondary to psychiatric condition) and potential secondary gains (eg, monetary compensation related to legal proceedings) impact, performance on diagnostic tools in ways that GSK-3 further complicate interpretation. For example, among returning OIF Soldiers, Vasterling and colleagues6 found increased reaction time, poor concentration, and short-term memory problems. Similarly, higher levels of combat intensity have been shown to be related to more efficient reaction time even 1 year postdeployment.30 Table III. Brain regions and functions often discussed in relationship to post-traumatic stress disorder (PTSD) and/or traumatic brain injury (TBI).**Acute mild, moderate, and severe Further complicating interpretation, for individuals with TBI and/or PTSD deficits in primary areas of cognitive functioning (eg, attention, processing speed) may undermine more complex processes (eg, executive functioning).