Psychological First Aid (PFA): RCT Adults Non-intentional Trauma Emergency Room

Background: Psychological First Aid (PFA) is currently the most recommended early intervention for people affected by recent traumatic events, especially in the aftermath of natural disasters. Unfortunately, there is no evidence that PFA neither prevents Post-Traumatic Stress Disorder (PTSD) nor other post-traumatic disorders or symptoms of distress. Objective: This project aims to evaluate the efficacy and safety of Psychological First Aid for the prevention of PTSD and other post-traumatic disorders and/or symptoms. Population: Investigators will perform a 1:1 randomized-controlled trial of 200 adults recently affected (\<=72 hours) by a non-intentional trauma who consult to the emergency room of a public hospital. Investigators estimated a sample size of 200 individuals in order to detect a 50% Relative Risk Reduction (RRR), with a power of 80%, a statistical significance (alpha) of 5% and 34,4% of PTSD prevalence in the control group, what is consistent with prevalences observed in a similar sample by Fullerton, Ursano, Epstein, Crowley, Vance et al. (2001). Intervention: In the emergency room, undergraduate psychology students, previously trained and certified in PFA, will search and randomize suitable patients to either PFA or treatment as usual (TAU). They will provide PFA according to a protocol based on the WHO PFA Operation Guide to those patients included in the active group. Everyone correctly randomized will be followed and clinically evaluated one month after the intervention (endpoint).