Trauma and its consequences in Iran: cross-cultural adaption and validation of the Global Psychotrauma Screen in a representative sample

Background: Potentially traumatic events may lead to the development of a wide range of adverse psychological responses, including symptoms of anxiety, depression, and (complex) posttraumatic stress disorder (PTSD). Despite the high prevalence of potentially traumatic events in Iran, there is no population data nor evidence-based instrument to screen for cross-diagnostic psychological responses to trauma. The Global Psychotrauma Screen (GPS) is a transdiagnostic self-report instrument for the detection of trauma-related symptoms, as well as risk and protective factors related to the impact of potentially traumatic events. Objective: The present study seeks to 1) translate and cross-culturally adapt the GPS in the Persian (Farsi) language and 2) examine the psychometric properties of the Persian GPS. Method: The translation and adaptation were performed using the Sousa and Rojjanasrirat (2011) method. A pilot study (n = 30) was carried out to test the content validity and test–retest reliability of the GPS. Next, in a representative sample (n = 800) of residents of Kermanshah City, the GPS, the General Health Questionnaire (GHQ) and the PTSD Checklist for DSM-5 (PCL-5) were administered. Construct validity of the Persian GPS was assessed using exploratory and confirmatory factor analysis. Additionally, we evaluated the convergent validity and internal consistency of the GPS. Results: Exploratory and confirmatory factor analyses indicated a three-factor model as the best solution with factors representing 1) Negative Affect, 2) Core PTSD symptoms and 3) Dissociative symptoms. The GPS total symptom score had high internal consistency and high convergent validity with related measures. A GPS total symptom cut-off score of nine was optimal for indicating a probable PTSD diagnosis based on the PCL-5. About half (52%) of the current sample met criteria for probable PTSD. Conclusions: The current findings suggest that the GPS can be effectively adapted for use in a non-Western society and, specifically, that the Persian GPS represents a useful, reliable and valid tool for screening of trauma-related symptoms in Iran.