THE BROWN ASSESSMENT OF BELIEFS SCALE - RELIABILITY AND VALIDITY

Objective: The authors developed and evaluated the reliability and val idity of the Brown Assessment of Beliefs Scale, a clinician-administer ed seven-item scale designed to assess delusions across a wide range o f psychiatric disorders, Method: The authors developed the scale after reviewing the literature on the assessment of delusions. Four raters administered the scale to 20 patients with obsessive-compulsive disord er (OCD), 20 patients with body, dysmorphic disorder, and 10 patients with mood disorder with psychotic features. Audiotaped interviews of s cale administration conducted by one rater were independently scored b y the other raters to evaluate interrater reliability. The scale was a dministered to 27 patients twice to determine test-retest reliability. Other insight instruments as well as scales that assess symptom sever ity were administered to assess convergent and discriminant validity. Sensitivity to change was assessed in a multicenter treatment study of sertraline for OCD. Results: Interrater and test-retest reliability f or the total score and individual item scores was excellent, with a hi gh degree of internal consistency. One factor was obtained that accoun ted for 56% of the variance. Scores on the Brown Assessment of Beliefs Scale were lot correlated with symptom severity but were correlated w ith other measures of insight. The scale was sensitive to change in in sight in OCD but was not identical to improvement in severity. Conclus ions: The Brown Assessment of Beliefs Scale is a reliable and valid in strument for assessing delusionality in a number of psychiatric disord ers. This scale may help clarify whether delusional and nondelusional variants of disorders constitute the same disorder as well as whether delusionality affects treatment outcome and prognosis.