Factor structure of the Brief Psychiatric Rating Scale - Expanded (BPRS-E) in a large hospitalized sample.

Meta-analytically derived models of the BPRS-E factor structure were tested on a large (n = 33,903) hospitalized sample using confirmatory factor analysis. A modified four factor model (Positive symptoms, Negative symptoms, Affect, and Activation) containing 12 core BPRS-E symptoms based on the meta-analytic models had excellent model fit. An additional five factor, 15 core symptom model, which added a Disorganization factor consistent with the pentagonal model of schizophrenic symptoms also had support with generally good fit. These factors demonstrated acceptable reliability as measured by coefficient alpha (M = 0.77). These factors were compared across three major diagnostic classes and indicated clinically relevant differences between these groups such as depressed patients having higher Affect scores (d = 1.03), manic-mixed episode patients having higher Activation scores (d = 0.83) and schizophrenic patients having higher Positive Symptom scores (d = 0.89) providing evidence for the validity of these factors. Further exploratory factor analyses provided support for the factors of Positive symptoms, Negative symptoms, Affect, and Activation with additional smaller and less robust factors corresponding to Resistance emerging as a fifth factor and Disorganization emerging as a sixth factor.