This study aimed to investigate brain alterations that occur soon after a traumatic experience and ascertain if they can predict the development of chronic post-traumatic stress disorder (PTSD). Beginning in 2016, the study recruited over 280 individuals who had survived a traumatic event from emergency departments of hospitals in the United States of America. Participants completed fMRI tasks within 10 days of surviving a traumatic incident and were followed up at 2 weeks, 3 months, between 6 and 9 months, and 12 months after recruitment.