On Combat

Colonel Charles Hoge of Walter Reed published a study on Mild Traumatic Brain Injury in U.S. Soldiers Returning from Iraq in the New England Journal of Medicine this month.

Their major finding was that there is a high correlation between a mild traumatic brain injury (mild TBI) that was severe enough to cause unconsciousness and PTSD, but there was a lower correlation if there was mental confusion without unconsciousness.

43.9% with mild TBI/loss of consciousness met criteria for PTSD
27.3% with mild TBI/altered mental status met criteria for PTSD
9.1% with mild TBI/no injuries met criteria for PTSD

The study doesn’t get us any closer to reconciling the differing perspectives on whether PTSD is caused by organic or psychological mechanisms….One might effectively argue the organic aspect of a concussion resulting in unconsciousness is a severe physical shock to the brain. The opposite argument is likely to be that an event powerful enough to result in unconscousness is likely to be psychologically shocking as well.

Interestingly, Hoge et al, and more prominently, Dr Richard Bryant (in an accompanying editorial, Disentangling Mild Traumatic Brain Injury and Stress Reactions) caution against informing troops of “a postconcussive syndrome” due to the risk of creating a new syndrome,

If troops currently serving in Iraq or Afghanistan are informed about a postconcussive syndrome and persistent problems emerging from mild traumatic brain injury, a new syndrome could arise from the current conflict in which soldiers attribute a range of common stress reactions to the effects of brain injury. This could be damaging to morale and to the person’s future mental health, because it could lead to the expectation of poor recovery. In contrast, the normalization of many of these reactions and the recognition that stress-related conditions can be managed with evidence-based strategies may minimize the unnecessary attribution of common stress reactions to pathology and facilitate resilience after mild traumatic brain injury.