This study utilized multiple criterion group neuropsychological samples to evaluate the "over-reporting" and "under-reporting" MMPI-2-RF validity scales. The five criterion groups included in this study were (1) litigating traumatic brain injury patients who failed Slick et al. criteria for probable malingering, (2) litigating traumatic brain injury patients who passed Slick et al. criteria, (3) mixed neuropsychological outpatients who passed SVTs and were diagnosed with primary neurological conditions, (4) mixed neuropsychological outpatients who passed SVTs and were diagnosed with primary psychiatric conditions, and (5) epileptic seizure disorder inpatients who were diagnosed via video-EEG. Using the data from these groups, cumulative percentages for all possible T-scores and sensitivity and specificity rates for optimal cutoff scores were determined. When specificity rates were set at 90% across all non-malingering neurological condition groups, sensitivity rates ranged from 48% (FBS-r) to 10% (K-r).

Both the literature and our findings show the Coin-in-the-Hand Test to have potential as a quick and easy screening tool to detect neurocognitive symptom exaggeration. This test could effectively supplement commonly used neurocognitive screens such as the Mini-Mental State Examination, the Saint Louis University Mental Status Examination, and the Montreal Cognitive Assessment.

This study examined differences in raw scores on the Symptom Validity Scale and Response Bias Scale (RBS) from the Minnesota Multiphasic Personality Inventory-2 in three criterion groups: (i) valid traumatic brain injured, (ii) invalid traumatic brain injured, and (iii) psychogenic non-epileptic seizure disorders. Results indicate that a >30 raw score cutoff for the Symptom Validity Scale accurately identified 50% of the invalid traumatic brain injured group, while misclassifying none of the valid traumatic brain injured group and 6% of the psychogenic non-epileptic seizure disorder group. Using a >15 RBS raw cutoff score accurately classified 50% of the invalid traumatic brain injured group and misclassified fewer than 10% of the valid traumatic brain injured and psychogenic non-epileptic seizure disorder groups. These cutoff scores used conjunctively did not misclassify any members of the psychogenic non-epileptic seizure disorder or valid traumatic brain injured groups, while accurately classifying 44% of the invalid traumatic brain injured individuals. 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.

Our findings provide further evidence of cognitive interindividual variability in a confirmed case of Susac's syndrome.