Another look at paradoxical severity effects in head injury with the Personality Assessment Inventory

Previous investigations of psychiatric symptomatology after head injury using the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) have consistently revealed greater Basic scale elevations in mild injuries versus more severe injuries. In this study, we tested this pattern of paradoxical severity effects using the Personality Assessment Inventory (PAI; Morey, 1991). We gathered PAI and MMPI-2 data from 34 patients with moderate-to-severe head injuries and from 52 patients with mild head injuries. MMPI-2 Basic scale profiles were consistent with the paradoxical severity effect; mild injury patients had significantly more elevated scores on four Basic scales (Scales 1, 2, 3, and 7). PAI Clinical scale profiles showed significantly more elevated scores among mild injury patients on 2 scales, Somatization and Depression, and more elevated scores among moderate-to-severe patients on 2 scales, Antisocial Features and Alcohol Problems. We consider unique contributions of the PAI for the psychological assessment of head injury.