The project proposes a novel preclinical approach to study risk factors for and neurobiology of post-traumatic stress and depression. Why risk factors. Because PTSD is the only psychiatric disorder to which there is seemingly a clear etiological agent- a traumatic event that triggers it, most animal models of PTSD concentrate on what would constitute a trauma in the studied animals. However, because the majority of people exposed to traumatic experiences actually develop PTSD the exposure to the traumatic experience is necessary, but no a sufficient condition to induce disorder. We focus on both distal (childhood adversities) and proximal (sleep restriction) potential risk factors, with high relevance to soldiers; (1) To establish an effective animal model of PTSD that would consider the contribution of risk factors to the introduction of PTSD; (2) To examine the role of sleep restriction as a proximal risk factor of PTSD; (3) To establish the role of childhood adversities as a long-term risk factor in PTSD, particularly in association with sleep restriction; (4) To develop the model as a platform for pharmacological testing of novel targets for drug development.