Confirmatory Factor Analysis of the Brief Psychiatric Rating Scale-Expanded in Veterans With Comorbid Posttraumatic Stress Disorder and Severe Mental Illness

Objective: Individuals with posttraumatic stress disorder (PTSD) and comorbid severe mental illness (SMI) are often underserved and undertreated. Empirical validation of commonly used measures of psychiatric symptoms in clinical practice, such as the Brief Psychiatric Rating Scale-Expanded (BPRS-E), is warranted in this vulnerable population. As such, this study sought to validate the factor structure and examine the psychometric properties of the BPRS-E among Veterans with comorbid PTSD and SMI. Methods: The study sample included 126 Veterans with comorbid PTSD and SMI recruited for a larger randomized controlled trial. Confirmatory factor analysis was conducted to compare the fit of five potential factor structures. Construct validity was evaluated using Pearson correlation coefficients. Results: Confirmatory factor analysis revealed that the four-factor model with 12 core items and the five-factor model with 15 items demonstrated a satisfactory fit. Construct validity evidence was provided for the BPRS-E total score via a moderate correlation with the Hamilton Depression Rating Scale, as well as weak but significant correlations with the Beck Depression Inventory and Clinician-Administered PTSD Scale. Conclusions and Implications for Practice: This study is the first to examine the factor structure of the BPRS-E for individuals with PTSD and SMI. Our results support the BPRS-E as a reliable and valid assessment of psychiatric symptoms in this population.