Project Summary The coronavirus disease 2019 (COVID-19) pandemic has caused fear, stress, and emotional trauma due to loss of lives, widespread sickness, extended social isolation, and financial insecurity. Pandemic-related experiences can lead to post-traumatic stress symptoms (PTSS) and other mental health problems and can exacerbate pre-existing mental health conditions. Neuroimaging studies suggest that PTSS and other mental health symptoms involve emotion dysregulation that emerges from functional and structural alterations of brain emotion circuits. Extending pre-pandemic neuroimaging research on PTSD development, this application proposes to use neuroimaging and behavioral data from adult pre-pandemic trauma survivors, who subsequently developed or did not develop PTSD prior to the pandemic, as baselines from which to longitudinally study pandemic effects on PTSS and associated brain emotion systems in these same subjects. Pandemic emotional experiences associated with, e.g., coronavirus infection, social isolation, and financial insecurity will be analyzed with respect to pre- vs. peri-pandemic changes in PTSS, other mental health symptoms, brain structure, and brain activation to fear emotion related tasks. Peri-pandemic symptoms and brain measures will also be compared in pre-pandemic PTSD vs. non-PTSD groups to test if these groups are being affected in similar or different ways. Comparison of pre- vs. peri- pandemic data in the same subjects will optimize resolution of how the pandemic is affecting mental health and brain function and structure and of how the pandemic is affecting people with different pre-pandemic PTSD dispositions. The results will identify ongoing mental health and brain effects of this pandemic and help prepare strategies to deal with its aftermath.