Many important gains have been made in understanding PTSD and other responses to trauma as a result of neuroscience-based observations. Yet there are many gaps in our knowledge that currently impede our ability to predict those who will develop pathologic responses. Such knowledge is essential for developing appropriate strategies for mounting a mental health response in the aftermath of terrorism and for facilitating the recovery of individuals and society. This paper reviews clinical and biological studies that have led to an identification of pathologic responses following psychological trauma, including terrorism, and highlights areas of future-research. It is important to not only determine risk factors for the development of short- and long-term mental health responses to terrorism, but also apply these risk factors to the prediction of such responses on an individual level. It is also critical to consider the full spectrum of responses to terrorism, as well as the interplay between biological and psychological variables that contribute to these responses. Finally, it is essential to remove the barriers to collecting data in the aftermath of trauma by creating a culture of education in which the academic community can communicate to the public what is and is not known so that survivors of trauma and terrorism will understand the value of their participation in research to the generation of useful knowledge, and by maintaining the acquisition of knowledge as a priority for the government and those involved in the immediate delivery of services in the aftermath of large-scale disaster or trauma.