Previous four- and five-factor solutions of the 18-item Brief Psychiatric Rating Scale (BPRS) suggested the possibility of an affective dimension in psychosis. A principal components analysis was used to analyze psychiatric symptom data rated on an expanded 24-item version of the BPRS. BPRS data were collected during a period of acute psychotic and affective illness with 114 young adult, recent-onset schizophrenia and schizoaffective patients and 27 bipolar manic patients. Principal components analyses of the 18-item and 24-item BPRS indicated a four-factor solution was the most interpretable. Principal components analysis of the 24-item BPRS produced a clear mania factor characterized by high loadings from items added to the 18-item BPRS, which included elevated mood, motor hyperactivity, and distractibility. This factor solution suggests that the 24-item BPRS allows for an expanded assessment of affective symptoms relating to a manic dimension. Potentially important symptoms that were added to the traditional 18-item version, namely suicidality, bizarre behavior, and self-neglect, also make clear contributions to other factors.
The Brief Psychiatric Rating Scale (BPRS; Overall and Gorham, 1962) was initially developed as a rapid method to assess symptom change in psychiatric inpatients of various diagnoses and has become one of the most widely used semi-structured instruments in psychiatric research. The original 16-item BPRS was expanded to 18 items (Overall and Klett, 1972). The 18-item version was expanded to 24 items through the addition of six symptom items — bizarre behavior, self-neglect, suicidality, elevated mood, distractibility, and motor hyperactivity — to increase sensitivity to a broader range of psychotic and affective symptoms (Lukoff et al., 1986). The latest version of the expanded 24-item BPRS provides detailed anchor points and probe questions for each item (Ventura et al., 1993). Studies have shown the expanded 24-item BPRS to be a sensitive and effective measure of psychiatric symptoms with good interrater reliability that can be maintained over time (Ventura Green et al., 1993 and Roncone et al., 1999).
Psychiatric symptom data gathered with the BPRS have been factor analyzed to identify symptom dimensions in psychiatric disorders. However, most of the factor analyses have used the 16- or 18-item BPRS and were performed on schizophrenia patients who were chronically ill (Guy, 1976, Overall and Beller, 1984, Malla et al., 1993, Mueser et al., 1997 and Long and Brekke, 1999). To our knowledge, there are only three published factor analyses of the 24-item BPRS (van der Does et al., 1993, Dingemans et al., 1995 and Burger et al., 1997). Van der Does et al. (1993) reported a four-factor solution with a sample of recent-onset schizophrenia patients and Dingemans et al. (1995) a five-factor solution with a diverse sample of psychiatric inpatients. The items of Motor Hyperactivity, Distractibility, and Elevated Mood, which were added to the 18-item version, help to form for van der Does et al. a ‘disorganization’ factor and for Dingemans et al. a ‘mania’ factor. Burger et al. (1997) reported a five-factor solution for the 24-item BPRS with a sample of homeless, chronically mentally ill patients, including factors for positive symptoms, negative symptoms, anxious–depressive symptoms, hostile–suspiciousness, and ‘activity.’ Thus far, it appears that the composition of factors for the 24-item BPRS varies across samples. Furthermore, it is unclear whether a meaningful and replicable fifth factor is present.
In an attempt to replicate previous research, the present study examined the factor structure of symptom ratings on the expanded 24-item BPRS in a sample of recent-onset schizophrenia patients and bipolar manic patients, most of whom also represented recent-onset disorders. The patients were participating in studies at the research center that developed the 24-item version of the BPRS.
