European Journal of Trauma & Dissociation 8 (2024) 100384 Available online 19 January 2024 2468-7499/© 2024 Elsevier Masson SAS. All rights reserved. Research Paper Validation of the Global Psychotrauma Screen for adolescents in Greece Ioanna Koutsopoulou a , Emma Grace b, * , Evgenia Gkintoni c , Miranda Olff d, e a Department of Psychology, General Hospital “Agios Andreas,” Patras, Greece b International Psychology Program, College of Graduate and Professional Studies, The Chicago School, United States c Department of Psychology, University General Hospital of Patras & University of Ioannina, Greece d Department of Psychiatry, Amsterdam Neuroscience & Public Health, Amsterdam UMC, Amsterdam, The Netherlands e ARQ National Psychotrauma Centre, Diemen, The Netherlands A R T I C L E INFO Keywords: Global Psychotrauma Screen Adolescents Screening Trauma Dissociation ABSTRACT Introduction: Adolescents are vulnerable to traumatic exposure. However, there is a lack of developmentally appropriate, freely accessible, transdiagnostic screening instruments for trauma in adolescents. The purpose of this study was to examine the psychometric potential of the Global Psychotrauma Screen Teen version (GPS-T) for the assessment of traumatic, dissociative, and other transdiagnostic symptoms among adolescents in Greece. Method: This observational study was conducted with adolescents in Greece (N = 122) who completed a 55-item questionnaire. Results: The results supported satisfactory internal consistency reliability, convergent validity, and divergent validity of the GPS-T. The construct validity findings suggested a three-factor structure of the GPS-T symptoms. The GPS-T domains had acceptable sensitivity and specificity with the cut-off scores of 3 for PTSD and 2 for the dissociation, anxiety, and depression domains respectively. The GPS-T symptoms differed on four levels of severity. Conclusion: The findings suggest that the GPS-T is appropriate for screening of traumatic, dissociative, and other transdiagnostic symptoms among adolescents in Greece. Future research should conduct a replication with larger samples and a test-retest phase. 1. Introduction 1.1. Trauma in adolescents Exposure to potentially traumatic events (PTEs) is common in ado- lescents (Connell et al., 2018; Darnell et al., 2019), often resulting in trauma-related disorders during this developmental stage that can persist into adulthood (Copeland et al., 2018; Frewen et al., 2024; Kessler et al., 2017; King et al., 2020; McKay et al., 2021). Over 60% of youth are exposed to at least one PTE and between 8%-25% of them develop PTSD before they reach the age of 18 years (Darnell et al., 2019; McLaughlin, 2023). In Greece, the United Nations Children’s Fund (UNICEF, 2020) reported that 70% of adolescents were exposed to psychological violence, 47.7% to physical violence, and 9.8% to sexual violence. However, PTSD is underdiagnosed among adolescents in Greece (Belivanaki et al., 2017). Symptoms of PTSD in youth can be comorbid with dissociation (Anderson et al., 2023; Choi et al., 2019; Choi et al., 2017; Howard et al., 2021), depression, anxiety (Cao et al., 2021; Darnell et al., 2019), and sleep disorders (Armour et al., 2014). Such comorbidities require a transdiagnostic assessment using a dimensional approach (Frewen et al., 2021; Olff et al., 2021; Williamson et al., 2021). 1.2. Screening of trauma in adolescents Several measures for screening of trauma have been developed and validated for adolescents using a discrete-disorder approach; however, they do not account for the transdiagnostic nature of trauma-related symptoms and do not differentiate between the child and adolescent age groups (Grace et al., 2021). The Global Psychotrauma Screen (GPS) was developed by an international group of trauma experts with the Global Collaboration on Traumatic Stress (GCTS) to address the need for Abbreviations: GPS, Global Psychotrauma Screen; CRIES, Children’s Revised Impact of Event Scale; DES-B, Brief Dissociative Experiences Scale; GAD, Generalized Anxiety Disorder; PHQ, Patient Health Questionnaire. * Corresponding author. E-mail address: egrace@thechicagoschool.edu (E. Grace). Contents lists available at ScienceDirect European Journal of Trauma & Dissociation journal homepage: www.elsevier.com/locate/ejtd https://doi.org/10.1016/j.ejtd.2024.100384 Received 12 November 2023; Received in revised form 15 January 2024; Accepted 15 January 2024