Roger O. Gervais

Development and validation of a Response Bias Scale (RBS) for the MMPI-2.

This study describes the development of a Minnesota Multiphasic Personality Inventory (MMPI-2) scale designed to detect negative response bias in forensic neuropsychological or disability assessment settings. The Response Bias Scale (RBS) consists of 28 MMPI-2 items that discriminated between persons who passed or failed the Word Memory Test (WMT), Computerized Assessment of Response Bias (CARB), and/or Test of Memory Malingering (TOMM) in a sample of 1,212 nonhead-injury disability claimants. Incremental validity of the RBS was evaluated by comparing its ability to detect poor performance on four separate symptom validity tests with that of the F and FP scales and the Fake Bad Scale (FBS). The RBS consistently outperformed F, FP, and FBS. Study results suggest that the RBS may be a useful addition to existing MMPI-2 validity scales and indices in detecting symptom complaints predominantly associated with cognitive response bias and overreporting in forensic neuropsychological and disability assessment settings.

Incremental Validity of the MMPI-2-RF Over-reporting Scales and RBS in Assessing the Veracity of Memory Complaints

The Response Bias Scale (RBS) has been found to be a better predictor of over-reported memory complaints than Minnesota Multiphasic Personality Inventory-2 (MMPI-2) F, Back Infrequency (Fb), Infrequency-Psychopathology (Fp), and FBS scales. The MMPI-2-Restructured Form (RF) validity scales were designed to meet or exceed the sensitivity of their MMPI-2 counterparts to symptom over-reporting. This study examined the incremental validity of MMPI-2-RF validity scales and RBS in assessing memory complaints. The MMPI-2-RF over-reporting validity scales were more strongly associated with mean Memory Complaints Inventory scores than their MMPI-2 counterparts (d = 0.22 to 0.49). RBS showed the strongest relationship with memory complaints. Regression analyses demonstrated the incremental validity of the MMPI-2-RF Infrequent Responses, Infrequent Psychopathology Responses, Infrequent Somatic Responses, and FBS-r scales relative to MMPI-2 F, Fp, and FBS in predicting memory complaints. This is consistent with the development objectives of the MMPI-2-RF validity scales as more efficient and sensitive measures of symptom over-reporting.

Further Validation of the MMPI-2 and MMPI-2-RF Response Bias Scale: Findings From Disability and Criminal Forensic Settings

The present study extends the validation of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) Response Bias Scale (RBS; R. O. Gervais, Y. S. Ben-Porath, D. B. Wygant, & P. Green, 2007) in separate forensic samples composed of disability claimants and criminal defendants. Using cognitive symptom validity tests as response bias indicators, the RBS exhibited large effect sizes (Cohens ds = 1.24 and 1.48) in detecting cognitive response bias in the disability and criminal forensic samples, respectively. The scale also added incremental prediction to the traditional MMPI-2 and the MMPI-2-RF overreporting validity scales in the disability sample and exhibited excellent specificity with acceptable sensitivity at cutoffs ranging from 90T to 120T. The results of this study indicate that the RBS can add uniquely to the existing MMPI-2 and MMPI-2-RF validity scales in detecting symptom exaggeration associated with cognitive response bias.

Differential sensitivity of the Response Bias Scale (RBS) and MMPI-2 validity scales to memory complaints

The MMPI-2 Response Bias Scale (RBS) is designed to detect response bias in forensic neuropsychological and disability assessment settings. Validation studies have demonstrated that the scale is sensitive to cognitive response bias as determined by failure on the Word Memory Test (WMT) and other symptom validity tests. Exaggerated memory complaints are a common feature of cognitive response bias. The present study was undertaken to determine the extent to which the RBS is sensitive to memory complaints and how it compares in this regard to other MMPI-2 validity scales and indices. This archival study used MMPI-2 and Memory Complaints Inventory (MCI) data from 1550 consecutive non-head-injury disability-related referrals to the first authors private practice. ANOVA results indicated significant increases in memory complaints across increasing RBS score ranges with large effect sizes. Regression analyses indicated that the RBS was a better predictor of the mean memory complaints score than the F, FB, and FP validity scales and the FBS. There was no correlation between the RBS and the CVLT, an objective measure of verbal memory. These findings suggest that elevated scores on the RBS are associated with over-reporting of memory problems, which provides further external validation of the RBS as a sensitive measure of cognitive response bias. Interpretive guidelines for the RBS are provided.

Objective tests of symptom exaggeration in independent medical examinations.

Objective: This study used the Medical Symptom Validity Test (MSVT) to examine exaggeration of memory impairment in disability claimants. Methods: The MSVT was administered to patients with soft tissue injuries undergoing an independent medical examination (IME). Their results were compared with those from groups of volunteers who were either trying their best on the test or simulating memory impairment. Results: Non-French-speaking volunteers, who were tested in French, showed near perfect performance on the effort subtests, but 42% of IME patients failed the effort tests in English. Their overall results were very similar to those of simulators. Conclusion: This study suggests that exaggeration of cognitive symptoms is widespread in disability-related evaluations. It would be unwise to accept self-reported memory complaints at face value. Criteria-normed symptom validity testing should be done to rule out symptom exaggeration.

Relationships between olfactory discrimination and head injury severity

The goal of this study was to examine the relationship between brain injury severity and scores on both an olfactory identification test and on many widely used neuropsychological tests in 367 patients with head injuries of varying levels of severity. It was hypothesized that valid olfactory test scores would correlate highly with injury severity because both the olfactory nerves and the primary olfactory cortices are especially vulnerable to damage in closed head injury. After removing data of doubtful validity from cases failing effort tests, olfactory test scores were related to Glasgow Coma Scale scores (GCS), post-traumatic amnesia and radiological abnormalities more strongly than any of the neuropsychological test scores. Based on the assumption that post-traumatic amnesia is caused by a different mechanism than loss of core consciousness, it was also predicted that there would be no cases with a GCS less than 13 and with no post-traumatic amnesia. As predicted, there were no cases in this group. The results support previous studies showing greater olfactory impairment with increased severity of head injury.

The Fake Bad Scale and MMPI-2 F-family in detection of implausible psychological trauma claims.

We tested the validity of the Lees-Haley Fake Bad Scale (FBS) and the family of MMPI-2 F scales (F-family; F, F(p), and F-K scales) in predicting improbable psychological trauma claims in an applied setting. Litigants reporting implausible symptoms long after minor scares and nonlitigants clinically referred following severe stressors completed the MMPI-2. Both groups were naturally matched on social class. The FBS demonstrated sensitivity, specificity, and positive predictive power in the detection of atypical problems but the F-family showed poor utility. FBS cutting scores derived from logistic regression were applied to a third group made up of litigants with histories of undeniably severe traumas. A substantial number of this third group scored above cutoffs for exaggeration, but this finding is ambiguous. Reasons for the F-familys insensitivity to real-world exaggeration may include using student simulators for validation and content reflective of psychotic simulation. The superiority of the FBS in applied forensic settings could derive from its development in actual litigants and content reflective of nonpsychotic exaggerations. The FBS appears acceptable for use in applied forensic settings where persons seek compensation for nonpsychotic syndromes.

The effect of failure on cognitive and psychological symptom validity tests in litigants with symptoms of post-traumatic stress disorder.

This study examined the influence of performance on cognitive and psychological symptom validity tests on neuropsychological and psychological test performance in claimants evaluated in a medico-legal context (N  = 301) with symptoms of PTSD. A second purpose of this study was to examine the influence of the severity of PTSD symptoms on cognitive test performance after excluding patients who failed to put forth adequate best effort and who exaggerated psychiatric symptoms. Patients were administered a battery of neuropsychological measures that were aggregated into a composite measure, the Cognitive-Test Battery Mean (C-TBM). Patients were also administered a battery of psychological tests that were aggregated into another composite measure, the Psychological-Test Battery Mean (P-TBM). We found that failure on cognitive symptom validity tests was associated with significantly poorer neuropsychological functioning, but there was not a significant effect on psychological symptoms. Conversely, failure on psychological symptom validity tests was associated with higher levels of psychopathology, but there was not a significant effect on cognitive ability. Finally, once patients were screened for adequate effort and genuine symptom reporting, the severity of PTSD symptoms did not appear to influence cognitive ability. This is the first study that assessed both types of symptom validity testing in PTSD claimants, which is important given that previous literature has demonstrated cognitive impairment in PTSD and that individuals with PTSD tend to claim cognitive impairment. Implications of these findings are discussed with regard to the existing literature and the relationship between these two types of symptom validity tests.

Symptom expectation after minor head injury. A comparative study between Canada and Lithuania

OBJECTIVES The purpose of the present study is to compare the frequency and nature of expected symptoms in Lithuania (a country where the chronic post-concussive syndrome is largely unknown) with that in Canada. METHODS A symptom checklist was administered to two subject groups selected from local companies in Kaunas, Lithuania, and Edmonton, Canada, respectively. Subjects were asked to imagine having suffered head trauma with loss of consciousness in a motor vehicle accident, and to check off symptoms they expected might arise from the injury. For symptoms they anticipated, they were asked to select the period of time they expected those symptoms to persist. RESULTS In both the Lithuanian and Edmontonian groups, the pattern of symptoms anticipated closely resembled the acute symptoms commonly reported by accident victims with minor head injury. Yet, while many Edmontonians also anticipated symptoms to last months or years, very few Lithuanian subjects selected any symptoms as being likely to persist in a chronic manner. CONCLUSIONS In Lithuania, despite the frequent experience of minor head injury in motor vehicle accidents, there is a very low rate of expectation of any chronic sequelae from such an injury, contrasting greatly with the response shown in Canada, where the prevalence of the chronic post-concussive syndrome is higher. Symptom expectation in some countries may be an important factor in the development of the chronic post-concussive syndrome.

Associations Between Symptom Validity Test Failure and Scores on the MMPI–2–RF Validity and Substantive Scales

This study examined the association between Symptom Validity Test (SVT) failure and the Minnesota Multiphasic Personality Inventory–2 Restructured Form (MMPI–2–RF; Ben-Porath & Tellegen, 2008), in the Forensic Disability Claimant samples described in the MMPI–2–RF Technical Manual (Tellegen & Ben-Porath, 2008a, 2008b). SVTs used included the Word Memory Test (Green, 2003), the Computerized Assessment of Response Bias (Allen, Conder, Green, & Cox, 1997), the Medical Symptom Validity Test (Green, 2004), and the Test of Memory Malingering (Tombaugh, 1996). SVT failure was associated with significant elevations throughout the MMPI–2–RF overreporting validity scales and substantive scales. Pairwise contrasts between groups failing 0 and 3 SVTs revealed predominantly large effect sizes for the overreporting validity scales (d = 0.78–1.11), and many of the substantive scales, including the Cognitive Complaints (COG) scale. Results of this study demonstrate an association between SVT performance and elevated scores on the MMPI–2–RF. These results suggest that exaggeration of cognitive symptoms as demonstrated by SVT failure is also associated with overreported emotional, somatic, and neurocognitive complaints on the MMPI–2–RF.