The best of two worlds: Combining the DSM-5 and ICD-11 clusters of symptoms for posttraumatic stress disorder in a single screening scale.

Objectives: The most recent DSM-5 (2013) and ICD-11 (2018) diagnostic criteria for posttraumatic stress disorder (PTSD) encompass 20 and six symptoms, respectively, organized in different structures. This study aimed to investigate the dimensions of the Posttraumatic Stress Disorder Checklist 5 (PCL-5) according to the DSM-5's broader definition of PTSD and the ICD-11's narrower approach, as well as to explore an alternative restricted model that retains the core symptoms explicitly related to traumatic experiences.

Methods: Data were gathered from Brazilian employees (n=1,101) who had directly experienced traumatic life events or had been exposed to them because of their work activities. Confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM) were used to evaluate the configural and metric structures of the models.

Results: We estimated seven models of the latent structure of PTSD including the four-factor DSM-5 and three-factor ICD-11 PTSD models. Given the lack of evidence of their validity, an alternative 10-symptom model was tested. The final seven-item PTSD model considerably improved estimation of the PTSD construct. This solution showed reliable items with non-redundant content, acceptable fit indices, and satisfactory configural and metric properties.

Conclusion: The more parsimonious one-dimensional model comprising the core PTSD symptoms has the potential to improve assessment of PTSD.