Neurological content and impact on Personality Assessment Inventory scale elevations / by Jeannette H. Prenger.

Abstract

The Minnesota Multiphasic Personality Inventory (MMPI/MMPI-2), the most frequently used measure ofpersonality and emotional frmctioning in clinical neuropsychological settings, does not meet current psychometric standards. The Personality Assessment Inventory (PAI; Morey, 1991) is a promising alternative to the MMPI, however its usefulness or clinical utility has not yet been formally examined. The present study was conducted to identify items ofthe PAI that might reflect neurological symptoms and to compare scale scores before and after adjustment for this content. AU 344 PAI items were examined by three neurospecialists. Twenty items were identified by these raters as representing physical effects produced by acquired brain injury (ABI) and experienced by at least one in four patients. Fifteen ofthese items were keyed on either the Somatic scale or the Schizophrenia Thought Disorder subscale. PAI profiles for 62 ABI patients were corrected for this content using the method of Gass (1991) for prorating scale scores on the MMPI-2 (i.e., differential endorsement neurological vs. non-neurologcal items). Although this correction significantly reduced mean sample scores across aU affected scales (F [8, 54] = 45.22, p < .001), the frequencies ofT scores > 69 were most reduced for the Somatic scale, from 32% to 8%, and the Schizophrenia Thought Disorder subscale, from 45% to 16%. Difference scores between ABI and normative responses were calculated. Nine of20 neurological items were among the highest discriminators between these two populations.