Neuropsychologist Expert Witness: Detection of Malingering
Three recently published articles in the Journal of Clinical Psychology are very helpful when dealing with the issue of the detection of malingering. In the most recent March 20, 2013, Differences in MMPI-2 FBS and RBS Scores in Brain Injury, Probable Malingering, and Conversion Disorder Groups: A Preliminary Study, the conclusion was:
Findings from this preliminary study suggest that the conjunctive use of the Symptom Validity Scale and the RBS from the Minnesota Multiphasic Personality Inventory-2 may be useful in differentiating probable malingering from individuals with brain injuries and conversion disorders.
In the article from June 18, 2012, Scores on the MMPI-2-RF Scales as a Function of Increasing Levels of Failure on Cognitive Symptom Validity Tests in a Military Sample, the authors concluded:
With respect to clinically significant elevations, those who did not fail SVTs had clinically significant elevations only on COG and NUC (Neurological Complaints), and MLS (Malaise) approached clinical significance. For those who failed SVTs, RBS was the only over-reporting scale that was elevated across all failure groups. Those who failed any SVT had clinically significant elevations on COG, MLS, NUC, and AXY. Those who failed three SVTs had additional elevations on scales related to emotional dysfunction.
A study of litigants and disability claimants was reported in, Performance Validity and Neuropsychological Outcomes in Litigants and Disability Claimants, the authors concluded:
The Fail group showed a higher percentage of impaired test scores than the Pass group with impairment defined at three levels (T scores < 40, 35, and 30). At the most conservative impairment cutoff (T < 30), 16% of the Pass group demonstrated impaired scores on more than three measures, while 79% of the Fail group showed impaired scores on more than three measures. The number of effort measures failed correlated highly with the overall test battery mean (r = -.73). On cognitive domain summary scores, effect sizes based on levels of effort (d = 1.12 to 1.86) were higher than those based on injury severity (d = 0.03 to 0.36).
These studies can be very helpful to attorneys, physicians, neuropsychologists, and others dealing with the detection of malingering by objective neuropsychological tests.