The issue of effortful patient performance has been an area of clinical interest in individuals with minor traumatic brain injury (mTBI). Clinical attention to this area has increased largely because of an increase in the number of worker's compensation claims, injury-related lawsuits and/or insanity defense pleas. As patients are presented with the opportunity for secondary gain, the issue of optimum performance on neuropsychological measures becomes salient. In addition to neurocognitive deficits, there are psychological characteristics associated with mTBI including depression, emotional disturbance, personality changes, and other psychopathology. This study utilized the MSVT, a set of standard neuropsychological instruments, and the Minnesota Multiphasic Inventory-2 (MMPI-2) to investigate the relationships between effort, psychological characteristics, and neuropsychological functioning in individuals with minor traumatic brain injuries. The first objective of this study was to determine which psychological factors were related to effort in mTBI. The second objective was to determine if there were differences between groups that performed poorly on effort testing and groups that performed adequately on effort testing, based on relevant psychological characteristics. The results of the analyses supported the first hypothesis. Hysteria was inversely related to effort, and Mania was positively related to effort on one of five measures of effort. The second hypothesis was not supported.

This study utilized the Medical Symptom Validity Test (MSVT) and a set of standard neuropsychological instruments to determine the underlying construct of the MSVT that accounts for effort in mild traumatic brain injury (mTBI) patients by comparing/contrasting mTBI with dementia and an analog simulation. The results indicate that a common underlying neurocognitive construct (memory) exists between mTBI and dementia patients, which may account for poor effort as measured by the MSVT. Other underlying factors emerged for both groups, though they did not point to a common construct. This finding suggests that the overall effect of brain injury in neurologically impaired groups also impacts effort performance as measured by the MSVT. Similarly impaired performance patterns also emerged between mTBI and dementia groups in sub-groups that failed effort measures. Thus, failed effort tests may be a function of more pronounced deficits in these groups, rather than a function of effort. Finally, although similar effort profiles were noted between mTBI and analog simulators, the analog group was unable to mimic the neurocognitive effects of mTBI.

This quasi-experimental study investigates neuropsychological functioning differences between 63 active duty soldiers who were placed into three groups (MTBI, PTSD, control) to provide better information for differentiating PTSD and MTBI. The ANAM and MicroCog were utilized to measure psychomotor speed, memory, and attention. Participants with PTSD performed worse on most measures of psychomotor speed and attention, and endorsed more symptoms of depression and anxiety when compared to MTBI and control participants. Further, attention appears to be the best cognitive domain for differentiating PTSD from MTBI, whereas memory variables did not differentiate these groups. Clinical and research implications of these findings are discussed.