title: Neurocognitive function differentiation from the effect of psychopathologic symptoms in the disability evaluation of patients with mild traumatic brain injury.
abstract: OBJECTIVE
  We determined whether the relationship between the neuropsychological performance of patients with mild traumatic brain injury (TBI) and their psychopathological characteristics measured by disability evaluation are interrelated. In addition, we assessed which psychopathological variable was most influential on neuropsychological performance via statistical clustering of the same characteristics of mild TBI.
  
  
  METHODS
  A total of 219 disability evaluation participants with mild brain injury were selected. All participants were classified into three groups, based on their psychopathological characteristics, via a two-step cluster analysis using validity and clinical scales from the Minnesota Multiphasic Personality Inventory (MMPI) and Symptom Checklist-90-revised (SCL-90-R). The Korean Wechsler Adult Intelligence Scale (K-WAIS), Korean Memory Assessment Scale (K-MAS) and the Korean Boston Naming Test (K-BNT) were used to evaluate the neurocognitive functions of mild TBI patients.
  
  
  RESULTS
  Over a quarter (26.9%) experienced severe psychopathological symptoms and 43.4% experienced mild or moderate psychopathological symptoms, and all of the mild TBI patients showed a significant relationship between neurocognitive functions and subjective and/or objective psychopathic symptoms, but the degree of this relationship was moderate. Variances of neurocognitive function were explained by neurotic and psychotic symptoms, but the role of these factors were different to each other and participants did not show intelligence and other cognitive domain decrement except for global memory abilities compared to the non-psychopathology group.
  
  
  CONCLUSIONS
  Certain patients with mild TBI showed psychopathological symptoms, but these were not directly related to cognitive decrement. Psychopathology and cognitive decrement are discrete aspects in patients with mild TBI. Furthermore, the neurotic symptoms of mild TBI patients made positive complements to decrements or impairments of neurocognitive functions, but the psychotic symptoms had a negative effect on neurocognitive functions.
authors.affiliation: Department of Psychiatry, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Jin-Sung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Oh-Lyong
authors.initials: OL
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Bon-Hoon
authors.initials: BH
authors.lastname: Koo
authors.affiliation: Department of Neurosurgery, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Min-Su
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Soon-Sub
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Cheon
keywords: Disability evaluation; Mild traumatic brain injury; Neuropsychological performance; Post-concussion syndrome