Relationships between mild traumatic brain injury sustained in combat and post-traumatic stress disorder.

The setting of the trauma is a distinguishing feature between mild traumatic brain injury (mTBI; also called concussion) that occurs in civilian settings compared with that occurring in combat. Combat mTBI is frequently associated with a prolonged stress reaction, post-traumatic stress disorder (PTSD). Individuals with mTBI and PTSD from combat in Operations Iraqi Freedom and Enduring Freedom often develop prolonged post-concussion symptoms (PCSs) such as headache. Both mTBI and PTSD may contribute to PCSs. PTSD may worsen and prolong the PCSs following mTBI by disrupting sleep. It is not known how mTBI predisposes an individual to develop PTSD.