Depression following brain trauma is enhanced in patients with mild discrepancies between intelligence and impairment on neuropsychological scores.

Analysis of the MMPI (Minnesota Multiphasic Personality Inventory) scores from 135 (20 years to 60 years old) patients who had sustained closed head injuries supported the hypothesis of a nonlinear relationship between the severity of depression and the magnitude of the discrepancy between intelligence and neuropsychological proficiency. Although the MMPI Depression T scores for all groups of patients were elevated (M = 78, SD = 13), patients with the least and greatest discrepancies between intelligence and neuropsychological proficiency scored lower on Depression than patients with discrepancies within the z-score ranges -2.0 and -1.1. The results of symmetrical covariance for either depression or complex partial epileptic-like experiences before comparisons between groups suggested depression and the epileptic-like experiences share the same source of variance.