Correlations between the MMPI and the Brief Psychiatric Rating Scale in schizophrenic and schizoaffective patients.

Though self-report measures and clinician-based ratings are extensively used to document psychopathology, there has been little work examining the relationship between these different types of measurement techniques. The current work examined the relationship between the Minnesota Multiphasic Personality Inventory (MMPI) and the Brief Psychiatric Rating Scale (BPRS) in patients with schizophrenia and schizoaffective disorder. Correlations were calculated in an initial exploratory sample, and a set of relationships was selected for confirmation in a second sample. The BPRS items of hallucinatory behavior and tension significantly correlated with MMPI measures of psychoticism. BPRS measures of hostility correlated with scale 4 (Psychopathic Deviate) of the MMPI. BPRS and MMPI measures of depression also were related. In contrast, BPRS and MMPI measures thought to reflect negative symptoms were uncorrelated. These results offer behavioral validity for the use of the MMPI in schizophrenic samples and suggest that the two measures tap similar as well as separable symptom constructs thought to be common in schizophrenia.