This study examines the psychological responses of a national probability sample of US residents to the September 11, 2001 terrorist attacks. The research was conducted through a longitudinal study, with assessments conducted at three waves: immediately after the attacks, 2 months later, and 6 months later. The study aimed to document the range of psychological responses, identify factors that influence these responses, and determine early predictors of distress and posttraumatic stress symptoms. Key findings include: - 60% of respondents watched the attacks live on TV. - 38% reported no direct firsthand exposure to the attacks. - Acute stress symptoms were reported by 4.99% at wave 1, 4.22% at wave 2, and 1.81% at wave 3. - Posttraumatic stress symptoms were reported by 4.22% at wave 2 and 1.81% at wave 3. - 64.6% reported fears of future terrorism at wave 2, and 37.5% at wave 3. - Predictors of posttraumatic stress symptoms included demographic factors, pre-September 11 health status, exposure to and loss due to the attacks, and coping strategies. - Predictors of global distress included severity of loss, coping strategies, and pre-September 11 mental and physical health status. The study highlights the importance of early coping strategies, with active coping being the only strategy found to be protective against ongoing distress. The findings suggest that the effects of a major national trauma can be long-lasting and that not all individuals directly affected by the attacks are equally impacted. This research provides valuable insights for healthcare professionals and interventions aimed at helping individuals cope with traumatic events.This study examines the psychological responses of a national probability sample of US residents to the September 11, 2001 terrorist attacks. The research was conducted through a longitudinal study, with assessments conducted at three waves: immediately after the attacks, 2 months later, and 6 months later. The study aimed to document the range of psychological responses, identify factors that influence these responses, and determine early predictors of distress and posttraumatic stress symptoms. Key findings include: - 60% of respondents watched the attacks live on TV. - 38% reported no direct firsthand exposure to the attacks. - Acute stress symptoms were reported by 4.99% at wave 1, 4.22% at wave 2, and 1.81% at wave 3. - Posttraumatic stress symptoms were reported by 4.22% at wave 2 and 1.81% at wave 3. - 64.6% reported fears of future terrorism at wave 2, and 37.5% at wave 3. - Predictors of posttraumatic stress symptoms included demographic factors, pre-September 11 health status, exposure to and loss due to the attacks, and coping strategies. - Predictors of global distress included severity of loss, coping strategies, and pre-September 11 mental and physical health status. The study highlights the importance of early coping strategies, with active coping being the only strategy found to be protective against ongoing distress. The findings suggest that the effects of a major national trauma can be long-lasting and that not all individuals directly affected by the attacks are equally impacted. This research provides valuable insights for healthcare professionals and interventions aimed at helping individuals cope with traumatic events.