The seventh in a series of congressionally mandated reports on Gulf War veterans health, this volume evaluates traumatic brain injury (TBI) and its association with long-term health affects. That many returning veterans have TBI will likely mean long-term challenges for them and their family members. Further, many veterans will have undiagnosed brain injury because not all TBIs have immediately recognized effects or are easily diagnosed with neuroimaging techniques. In an effort to detail the long term consequences of TBI, the committee read and evaluated some 1,900 studies that made up its literature base, and it developed criteria for inclusion of studies to inform its findings. It is clear that brain injury, whether penetrating or closed, has serious consequences. The committee sought to detail those consequences as clearly as possible and to provide a scientific framework to assist veterans as they return home.