Psychobiological Mechanisms of Resilience to Trauma

Since the majority of research studies in posttraumatic stress disorder (PTSD) have focused on the pathological consequences of exposure to trauma, there is a paucity of information on the psychobiology of subjects who are resilient to severe stress. The proposed study will comprehensively evaluate the neural circuits that mediate fear, reward, social cooperation, memory, and emotional regulation in traumatized men and women with and without PTSD and healthy subjects. Subject groups will include prisoners of war, active duty special operations forces, returning Iraqi veterans (approval pending), and men and women exposed to non-combat traumas including sexual and or physical abuse. Comparison groups will include men and women exposed to trauma without PTSD (resilient subjects), and healthy men and women who have never been exposed to trauma. Changes in neural circuitry associated with resilience will be evaluated using functional magnetic resonance imaging (fMRI). Relationships and interactions among the neural circuits mediating fear, reward, social cooperation, memory, and emotional regulation will be assessed and correlated with clinical, neuroendocrine, and neuropsychological findings. Identification of biological and psychosocial correlates of resilience could help predict illness vulnerability following exposure to trauma and could assist in the selection of "hardy" subjects for high-risk professions.