A parent?s experience of trauma has been shown to impact the psychological well-being of their children even when the children themselves were not directly exposed to the traumatic event. Research on the Intergenerational Transmission of Trauma (ITT) has demonstrated behavioral, cognitive, and emotional difficulties in offspring of traumatized parents, including hypervigilance, nightmares, difficulties in interpersonal functioning, and deficits in academic performance, along with mood and other psychiatric disorders. Studies examining the effects of trauma transmission from parents with post-traumatic stress disorder (PTSD), reported high rates of PTSD in their offspring. However, there is still debate regarding the proposed pathways of ITT explaining the increased risk for impaired psychological well-being in children of parents exposed to trauma. The burden of ITT has not received appropriate research consideration in children of World Trade Center Responders (WTC-R) given earlier reports of behavioral, psychological and health problems among these children, and evidence suggests that these difficulties and disorders will persist beyond the childhood years. This proposal aims to address this gap by establishing a new cohort of persons who were younger than 18 years of age at the time of the 9/11 terror attack, and whose parents developed PTSD after being exposed through their occupation to the terror attack and its aftermath. We will: a) assess the psychological well-being and risk factors of this cohort using an online battery of cognitive and emotional tasks and psychological instruments; and b) integrate data from the parent cohort with that collected on this new cohort to examine the possible mediators of ITT. Understanding ITT is a necessary prerequisite for formulating effective public health interventions after mass disasters.