Personality and the prediction of outcome following rehabilitation in persons with acquired brain injuries: The Millon Behavioral Medicine Diagnostic (MBMD)

Neuropsychological rehabilitation following acquired brain injury is increasingly recognized as essential with the advancements in research evidence of its effectiveness, particularly as current estimates of disability following the most common forms of brain injury (traumatic brain injury and cerebrovascular accident) are so high. Improvements in predictive capabilities of researchers and clinicians are paramount in designing effective interventions. As many variables associated with outcome following brain injury are not controllable (e.g. severity of the injury, age, education), it is essential that rehabilitation programs design interventions to target those variables that are susceptible to amelioration. While personality factors have been shown to affect outcome in other medical illnesses, only a few studies have examined the influence of personality on outcome following neurorehabilitation for acquired brain injury. The results of these studies have been mixed. This study used the Millon Behavioral Medicine Diagnostic (MBMD) to predict outcome as measured by the Mayo-Portland Adaptability Index (MPAI-4) following brain injury rehabilitation in a heterogeneous sample of persons with acquired brain injuries (N = 50).;It was hypothesized that specific coping styles scales from the MBMD (Introversive, Dejected, Oppositional), which are based on Millon's personality system, would predict outcome. Results indicated that both the Introversive and Oppositional coping styles scales accounted for significant amounts of variance in outcome beyond that accounted for by the severity of the injury alone (p < .001). In both cases, individuals with mild/moderate-moderate/severe limitations following completion of the rehabilitation program had significantly higher scores on the Introversive and Oppositional coping compared to individuals with more successful outcomes. The hypothesis that a dejected coping style would predict outcome was not supported. Implications for rehabilitation are discussed in the context of Millon's personality system.