Empirically derived psychopathology subgroups in traumatic brain injury.

The purpose of the present study was to identify psychopathology subgroups within three samples of individuals with traumatic brain injury (TBI). The majority of patients in all three samples met criteria for mild traumatic brain injury. Psychopathology was measured using two versions of the Millon Clinical Multiaxial Inventory (MCMI-I and MCMI-II). In each sample, selected MCMI scales were entered into multiple methods of hierarchical cluster analysis. In study 1, the MCMI-I profiles of 187 workers\u27 compensation claimants were analyzed. Study 2 involved the MCMI-II profiles of 88 workers\u27 compensation claimants. In study 3, the MCMI-II profiles of 70 medical-legal patients were studied. Three psychopathology subgroups, labeled Subclinical, Generalized Distress, and Withdrawn, were identified in all three studies. An Aggressive cluster was also found in the workers\u27 compensation samples (study 1 and 2). Within each study, the subgroups were recovered reliably using multiple cluster analysis methods. Modest evidence was found for differences between the subgroups with respect to demographic, injury severity, and neuropsychological test performance variables. Where differences were found, the Withdrawn subgroup was most likely to differ from one or more of the other subgroups. In study 1, patients in the Withdrawn cluster demonstrated older age, poorer Trail Making Test performance, longer posttraumatic amnesia (PTA), and trends toward a greater incidence of seizures and a greater percentage of immigrants. In study 2, the Withdrawn subgroup showed longer time since injury and shorter PTA than other subgroups. In study 3, the Withdrawn subgroup showed a greater proportion of males to females and poorer memory performance. All three study samples showed high rates of psychopathology. However, evidence of Axis I and Axis II psychopathology on the MCMI was rarely associated with poorer performance on neuropsychological tests. Future research should explore the relationship between psychopathology profiles, pre-injury risk factors, post-injury symptoms, and response to treatment following TBI.Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2001 .M55. Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4795. Adviser: Douglas Shore. Thesis (Ph.D.)--University of Windsor (Canada), 2001