Victoria Symptom Validity Test: efficiency for detecting feigned memory impairment and relationship to neuropsychological tests and MMPI-2 validity scales

Review of Statistical and Methodological Issues in the Forensic Prediction of Malingering from Validity Tests: Part II-Methodological Issues

Forensic neuropsychological examinations to detect malingering in patients with neurocognitive, physical, and psychological dysfunction have tremendous social, legal, and economic importance. Thousands of studies have been published to develop and validate methods to forensically detect malingering based largely on approximately 50 validity tests, including embedded and stand-alone performance and symptom validity tests. This is Part II of a two-part review of statistical and methodological issues in the forensic prediction of malingering based on validity tests. The Part I companion paper explored key statistical issues. Part II examines related methodological issues through conceptual analysis, statistical simulations, and reanalysis of findings from prior validity test validation studies. Methodological issues examined include the distinction between analog simulation and forensic studies, the effect of excluding too-close-to-call (TCTC) cases from analyses, the distinction between criterion-related and construct validation studies, and the application of the Revised Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) in all Test of Memory Malingering (TOMM) validation studies published within approximately the first 20 years following its initial publication to assess risk of bias. Findings include that analog studies are commonly confused for forensic validation studies, and that construct validation studies are routinely presented as if they were criterion-reference validation studies. After accounting for the exclusion of TCTC cases, actual classification accuracy was found to be well below claimed levels. QUADAS-2 results revealed that extant TOMM validation studies all had a high risk of bias, with not a single TOMM validation study with low risk of bias. Recommendations include adoption of well-established guidelines from the biomedical diagnostics literature for good quality criterion-referenced validation studies and examination of implications for malingering determination practices. Design of future studies may hinge on the availability of an incontrovertible reference standard of the malingering status of examinees.

Attention Performance as an Embedded Validity Indicator in the Cognitive Assessment of Early Retirement Claimants

The assessment of performance validity is essential in any neuropsychological evaluation. However, relatively few measures exist that are based on attention performance embedded within routine cognitive tasks. The present study explores the potential value of a computerized attention test, the Cognitrone, as an embedded validity indicator in the neuropsychological assessment of early retirement claimants. Two hundred and sixty-five early retirement claimants were assessed with the Word Memory Test (WMT) and the Cognitrone. WMT scores were used as the independent criterion to determine performance validity. Speed and accuracy measures of the Cognitrone were analyzed in receiver operating characteristics (ROC) to classify group membership. The Cognitrone was sensitive in revealing attention deficits in early retirement claimants. Further, 54% (n = 143) of the individuals showed noncredible cognitive performance, whereas 46% (n = 122) showed credible cognitive performance. Individuals failing the performance validity assessment showed slower (AUC = 79.1%) and more inaccurate (AUC = 79.5%) attention performance than those passing the performance validity assessment. A compound score integrating speed and accuracy revealed incremental value as indicated by AUC = 87.9%. Various cut scores are suggested, resulting in equal rates of 80% sensitivity and specificity (cut score = 1.297) or 69% sensitivity with 90% specificity (cut score = 0.734). The present study supports the sensitivity of the Cognitrone for the assessment of attention deficits in early retirement claimants and its potential value as an embedded validity indicator. Further research on different samples and with multidimensional criteria for determining invalid performance are required before clinical application can be suggested.

Classification of performance validity and symptom validity using the Trauma Symptom Inventory-2

The Trauma Symptom Inventory-Second Edition (TSI-2) is garnering research interest as a symptom validity test in the evaluation of trauma-related disorders. However, there has been limited empirical validation of its validity scales in clinical and forensic real-world settings. This study evaluated the ability of the TSI-2 Atypical Response (ATR) scale to discriminate response bias in cognitive performance and symptom reporting in a large sample of disability and compensation-seeking claimants. This retrospective chart review included 296 adults with a known history of trauma exposure or claimed trauma-related psychological injury who underwent neuropsychological and/or comprehensive psychological assessment in a private neuropsychology clinic. The discriminability of the ATR scale to classify credible versus non-credible cognitive profiles and symptom reporting were analyzed by AUC-ROCs. Overall, the ATR scale demonstrated poor discriminability of assessment validity based on the Word Memory Test, Victoria Symptom Validity Test, and Minnesota Multiphasic Personality Inventory-2-Restructured Form. The ATR scale had fair discriminatory ability of only one of the over-reporting scales (F-r), with an ROC area of .73, p = .001. However, the test publisher's proposed ATR cut-offs of ≥8 for screening, research, and normal groups, and ≥15 in forensic and clinical settings revealed significant issues with sensitivity and specificity. These results suggest that the TSI-2 should be paired with other established performance validity and symptom validity tests in clinical assessments and not be used as the primary or sole indicator of assessment validity.

The impact of visual memory impairment on Victoria Symptom Validity Test performance: A known-groups analysis

OBJECTIVE

We assessed the effect of visual learning and recall impairment on Victoria Symptom Validity Test (VSVT) accuracy and response latency for Easy, Difficult, and Total Items.

METHOD

A sample of 163 adult patients administered the VSVT and Brief Visuospatial Memory Test-Revised were classified as valid (114/163) or invalid (49/163) groups via independent criterion performance validity tests (PVTs). Classification accuracies for all VSVT indices were examined for the overall sample, and separately for subgroups based on visual memory functioning.

RESULTS

In the overall sample, all indices produced acceptable classification accuracy (areas under the curve [AUCs] ≥ 0.79). When stratified by visual learning/recall impairment, accuracy indices yielded acceptable classification for both the unimpaired (AUCs ≥0.79) and impaired subsamples (AUCs ≥0.75). Latency indices had acceptable classification accuracy for the unimpaired subsample (AUCs ≥0.74), but accuracy and sensitivity dropped for the impaired sample (AUCs ≥0.67).

CONCLUSIONS

VSVT accuracy and response latency yielded acceptable classification accuracies in the overall sample, and this effect was maintained in those with and without visual learning/recall impairment for the accuracy indices. Findings indicate that the VSVT is a psychometrically robust PVT with largely invariant cut-scores, even in the presence of bona fide visual learning/recall impairment.

Considerations regarding noncredible performance in the neuropsychological assessment of patients with multiple sclerosis: A case series

Determining the validity of data during clinical neuropsychological assessment is crucial for proper interpretation, and extensive literature has emphasized myriad methods of doing so in diverse samples. However, little research has considered noncredible presentation in persons with multiple sclerosis (pwMS). PwMS often experience one or more factors known to impact validity of data, including major neurocognitive impairment, psychological distress/psychogenic interference, and secondary gain. This case series aimed to illustrate the potential relationships between these factors and performance validity testing in pwMS. Six cases from an IRB-approved database containing pwMS referred for neuropsychological assessment at a large, academic medical center involving at least one of the above-stated factors were identified. Backgrounds, neuropsychological test data, and clinical considerations for each were reviewed. Interestingly, no pwMS diagnosed with major neurocognitive impairment was found to have noncredible performance, nor was any patient with noncredible performance in the absence of notable psychological distress. Given the variability of noncredible performance and multiplicity of factors affecting performance validity in pwMS, clinicians are strongly encouraged to consider psychometrically appropriate methods for evaluating validity of cognitive data in pwMS. Additional research aiming to elucidate base rates of, mechanisms begetting, and methods for assessing noncredible performance in pwMS is imperative.

Is computerized screening for processing speed impairment sufficient for identifying MS-related cognitive impairment in a clinical setting?

BACKGROUND

Annual screening for processing speed impairment (PSI) is recommended for patients with multiple sclerosis (pwMS). However, cognitive deficits in pwMS are heterogeneous, and whether PSI screening identifies patients with impairment in other cognitive domains is unclear. The objective of this study was to examine sensitivity and specificity of the self-administered, computerized Processing Speed Test (PST) in identifying cognitive impairment defined by a comprehensive neuropsychological battery (NPT).

METHODS

Ninety-one pwMS completed PST and NPT, with raw scores demographically adjusted. Cognitive impairment on NPT was defined as performance <5^th percentile in at least one domain. Receiver operating characteristic (ROC) analyses were performed to determine the ability of the PST to discriminate between cognitively normal (CN) and cognitively impaired with PSI (CI-PSI) and cognitively impaired with normal processing speed (CI-PSN) groups.

RESULTS

Cognitive impairment was observed in 23.1% of pwMS on PST and in 42.9% on NPT. PST demonstrated excellent ability to discriminate between CN (57.1%) and CI-PSI (20.9%) groups (Area Under the Curve [AUC] = 0.86, p < 0.001). In contrast, PST was unable to discriminate CN and CI-PSN (22.0%) groups (AUC = 0.42, p = 0.32).

CONCLUSION

The PST demonstrates excellent ability to detect PSI in pwMS but is unable to identify cognitively impaired pwMS without PSI, highlighting the importance of developing additional screening measures.

Clinical neuropsychology in Canada: results from the 2020 AACN, NAN, SCN professional practice and "salary survey"

Objective: The current study summarizes the results of a 2020 survey that solicited information regarding backgrounds, beliefs, practices, and incomes of clinical neuropsychologists who practice in Canada. Methods: Clinical neuropsychologists who practice in Canada were invited to participate in an online survey that was available from 1/17/20 to 4/02/20. Available survey findings were obtained from 111 respondents, which reflects a response rate of 51.3% of the 216 doctoral-level Canadian neuropsychologists identified in at least one major North American or international professional organization membership list (AACN, INS, NAN, or SCN). Results: Most of the current respondents were White/Caucasian women who identified as adult providers and worked full-time in urban institutional settings. Four Canadian provinces (Alberta, British Columbia, Ontario, Quebec) accounted for more than 91% of the current respondent sample. Incomes and career satisfactions were largely encouraging, though some important variations were noted by province, work setting, and professional identity. Incomes were significantly associated with forensic practices and years of clinical experience. Most respondents made use of technician support in their practices, largely to increase productivity and patient volume. Only a small minority of respondents were board-certified and there was generally limited interest in future board certification. Conclusions: While important similarities were observed in the current Canadian sample relative to recent survey findings obtained in a U.S. sample, results also reveal a number of important differences that serve as important areas of future consideration.

Response Time Measures as Supplementary Validity Indicators in Forced-Choice Recognition Memory Performance Validity Tests: A Systematic Review

Performance validity tests (PVTs) based on the forced-choice recognition memory (FCRM) paradigm are commonly used for the detection of noncredible performance. Examinees' response times (RTs) are affected by cognitive processes associated with deception and can also be gathered without lengthening the duration of the assessment. Consequently, interest in the utility of these measures as supplementary validity indicators in FCRM-PVTs has grown over the years. The current systematic review summarizes both clinical and simulation (i.e., healthy participants simulating cognitive impairment) studies of RTs in FCRM-PVTs. The findings of 25 peer-reviewed articles (n = 26 empirical studies) indicate that noncredible performance in FCRM-PVTs is associated with longer RTs. Additionally, there are indications that noncredible performance is associated with larger variability in RTs. RT measures, however, have lower discrimination capacity than conventional accuracy measures. Their utility may therefore lie in reaching decisions regarding cases with border zone accuracy scores, as well as aiding in the detection of more sophisticated examinees who are aware of the use of accuracy-based validity indicators in FCRM-PVTs. More research, however, is required before these measures are incorporated in daily practice and clinical decision-making processes.

Victoria Symptom Validity Test: A Systematic Review and Cross-Validation Study

The Victoria Symptom Validity Test (VSVT) is a performance validity test (PVT) with over two decades of empirical backing, although methodological limitations within the extant literature restrict its clinical and research generalizability. Chief among these constraints includes limited consensus on the most accurate index within the VSVT and the most appropriate cut-scores within each VSVT validity index. The current systematic review synthesizes existing VSVT validation studies and provides additional cross-validation in an independent sample using a known-groups design. We completed a systematic search of the literature, identifying 17 peer-reviewed studies for synthesis (7 simulation designs, 7 differential prevalence designs, and 3 known-groups designs). The independent cross-validation sample consisted of 200 mixed clinical neuropsychiatric patients referred for outpatient neuropsychological evaluation. Across all indices, Total item accuracy produced the strongest psychometric properties at an optimal cut-score of ≤ 40 (62% sensitivity/88% specificity). However, ROC curve analyses for all VSVT indices yielded statistically significant areas under the curve (AUCs; .73-81), suggestive of moderate classification accuracy. Cut-scores derived using the independent cross-validation sample converged with some previous findings supporting cut-scores of ≤ 22 for Easy item accuracy and ≤ 40 for Total item accuracy, although divergent findings were noted for Difficult item accuracy. Overall, VSVT validity indicators have adequate diagnostic accuracy across populations, with the current study providing additional support for its use as a psychometrically sound PVT in clinical settings. However, caution is recommended among patients with certain verified clinical conditions (e.g., dementia) and those with pronounced working memory deficits due to concerns for increased risk of false positives.

A comparison of the self-report patterns of analog versus real-world malingerers of attention deficit hyperactivity disorder

Much of what we know about malingering of attention deficit hyperactivity disorder (ADHD) has been learned from the performance of analog malingerers, typically first-year psychology students given credit for study participation. It is not clear, however, whether their performance is similar to that found in actual clinical settings. Indeed, past research suggests that analog malingerers may overexaggerate deficits relative to real-world malingerers, making them easier to identify in controlled studies. The purpose of the current study was, therefore, to compare the performance of analog malingers to post-secondary students strongly suspected of malingering ADHD on a self-report measure of ADHD symptoms. Their scores were, in turn, compared to those returned by students with genuine ADHD and clinical controls. Results demonstrated that, apart from analog subjects overexaggerating symptoms of hyperactivity, few differences exist between the scores returned by analog malingerers relative to clinical malingerers. While newly devised symptom validity measures show promise in identifying malingered ADHD, neither the analog nor the clinical malingers consistently failed these symptom validity scales. Furthermore, a good portion in both malingering groups failed to endorse high levels of ADHD symptoms in general. Clinical implications are discussed.

A Meta-Analysis of Neuropsychological Effort Test Performance in Psychotic Disorders

Psychotic disorders are characterized by a generalized neurocognitive deficit (i.e., performance 1.5 SD below controls across neuropsychological domains with no specific profile of differential deficits). A motivational account of the generalized neurocognitive deficit has been proposed, which attributes poor neuropsychological testing performance to low effort. However, findings are inconsistent regarding effort test failure rate in individuals with psychotic disorders across studies (0-72%), and moderators are unclear, making it difficult to know whether the motivational explanation is viable. To address these issues, a meta-analysis was performed on data from 2205 individuals with psychotic disorders across 19 studies with 24 independent effects. Effort failure rate was examined along with moderators of effort test type, forensic status, IQ, positive symptoms, negative symptoms, diagnosis, age, gender, education, and antipsychotic use. The pooled weighted effort test failure rate was 18% across studies and there was a moderate pooled association between effort failure rate and global neurocognitive performance (r = .57). IQ and education significantly moderated failure rate. Collectively, these findings suggest that a nontrivial proportion of individuals with a psychotic disorder fail effort testing, and failure rate is associated with global neuropsychological impairment. However, given that effort tests are not immune to the effects of IQ in psychotic disorders, these results cannot attest to the viability of the motivational account of the generalized neurocognitive deficit. Furthermore, the significant moderating effect of IQ and education on effort test performance suggests that effort tests have questionable validity in this population and should be interpreted with caution.

Refined Measurement of Verbal Learning and Memory: Application of Item Response Theory to California Verbal Learning Test - Second Edition (CVLT-II) Learning Trials

OBJECTIVE

This study was conducted to investigate how items contained within the California Verbal Learning Test - Second Edition (CVLT-II; Delis, D. C., Kramer, J. H., Kaplan, E., & Ober, B. A. (2000). California Verbal Learning Test (2nd ed.). San Antonio, TX: Psychological Corporation) learning trials function and to evaluate whether weighted scoring approaches might improve quantification of verbal memory.

METHOD

Archival data from 577 individuals (338 healthy young adults, 239 medical or psychiatric patients referred to a neuropsychology clinic) were obtained and evaluated using item response theory.

RESULTS

The serial position effect was evident across trials, but was most evident in Trials 1, 2, and 3. CVLT-II Trial 5 was the most effective among the five learning trials in quantifying verbal memory, although it was most effective when measuring lower memory ability levels. In contrast, CVLT-II Trial 1 items had, on average, the highest difficulty levels. Various weighted scoring approaches did not appear incrementally helpful in improving prediction of memory performance.

CONCLUSION

Specific items and trials differentially discriminate between examinees with low levels of memory ability; it is important to thoroughly evaluate item properties of tests used in clinical decision-making.

Blast concussion and posttraumatic stress as predictors of postcombat neuropsychological functioning in OEF/OIF/OND veterans

OBJECTIVES

Many combat veterans exhibit cognitive limitations of uncertain origin. In this study, we examined factors that predict cognitive functioning by considering effects of blast-related concussion (BRC), non-blast-related concussion (NBRC), and posttraumatic stress disorder (PTSD) symptoms. Analyses specifically tested whether (a) BRC and NBRC were distinct in their prediction of cognitive performance; (b) a dose-response relationship existed between recurrent concussion (BRC and NBRC) and cognitive impairment; and (c) PTSD symptoms mediated the relationship between BRC and cognitive performance.

METHOD

Two hundred eighty veterans with combat zone deployment histories completed semistructured clinical interviews to define BRC and NBRC histories, current and past mental health disorders, and dimensional ratings of PTSD symptomatology. Participants were also administered a number of neuropsychological measures to appraise cognitive functioning.

RESULTS

A structural equation model (SEM) suggested that BRC and NBRC were not distinct in their prediction of cognitive performance, and there was no evidence that recurrent concussion (blast or nonblast) was directly associated with cognitive performance. BRC was significantly associated with PTSD symptoms (r = .24), PTSD symptoms were significantly associated with cognitive performance in the SEM (r = -.27), and PTSD symptoms significantly mediated the link between BRC and cognitive performance (p = .03).

CONCLUSIONS

These results suggest that concussion history fails to directly contribute to cognitive performance, regardless of mechanism (blast or nonblast) and recurrence. BRC is nonetheless unique in its contribution to PTSD and PTSD-related cognitive deficits. Results support interventions specific to PTSD management in the interest of promoting neuropsychological functioning among war veterans. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

A Comparison of Performance Validity Measures in Predicting MMPI-2 Lie Scale Results

Objective: This study examined the relationship between tests of performance validity (PVT) and symptom validity (SVT) among claimants undergoing independent neuropsychological evaluations. Previous research comparing PVTs with SVTs has examined symptom validity with respect to overreporting impairment, whereas the current study focused on how PVTs predict underreporting of psychological symptoms and minimization of negative personality characteristics.Method: The sample included 99 claimants presenting with psychological and cognitive complaints who were assessed in a private practice setting. Participants were administered several SVTs (MMPI-2 Lie Scale (L), Superlative Self Presentation Scale (S), Correction Scale (K)) and PVTs, including Reliable Digit Span (RDS), California Verbal Learning Test forced choice recognition, the Victoria Symptom Validity Test (VSVT), and the Test of Memory Malingering (TOMM).Results: Analyses revealed moderate yet significant (p<.001) negative correlations between the L Scale and PVTs with exception of the VSVT. These relationships were substantiated by moderate to large effect sizes (d = 0.56-0.81) when comparing L Scale scores in above and below PVT cutoff conditions. Significant relationships between PVTs and the K and S Scales were not observed. Exploratory analyses revealed that PVT/L Scale relationships were not significantly moderated by presenting concern.Conclusions: Claimants exhibiting invalid PVT performance were more likely to endorse virtuous personality characteristics on the L Scale, supporting the idea that PVT and SVT constructs are interrelated, particularly in the domain of underreporting moral flaws.

The MMPI-2/MMPI-2-RF Symptom Validity Scale (FBS/FBS-r) is not a measure of 'litigation response syndrome': commentary on Nichols and Gass (2015)

OBJECTIVES

To address (1) Whether there is empirical evidence for the contention of Nichols and Gass that the MMPI-2/MMPI-2-RF FBS/FBS-r Symptom Validity Scale is a measure of Litigation Response Syndrome (LRS), representing a credible set of responses and reactions of claimants to the experience of being in litigation, rather than a measure of non-credible symptom report, as the scale is typically used; and (2) to address their stated concerns about the validity of FBS/FBS-r meta-analytic results, and the risk of false positive elevations in persons with bona-fide medical conditions.

METHOD

Review of published literature on the FBS/FBS-r, focusing in particular on associations between scores on this symptom validity test and scores on performance validity tests (PVTs), and FBS/FBS-r score elevations in patients with genuine neurologic, psychiatric and medical problems.

RESULTS

(1) several investigations show significant associations between FBS/FBS-r scores and PVTs measuring non-credible performance; (2) litigants who pass PVTs do not produce significant elevations on FBS/FBS-r; (3) non-litigating medical patients (bariatric surgery candidates, persons with sleep disorders, and patients with severe traumatic brain injury) who have multiple physical, emotional and cognitive symptoms do not produce significant elevations on FBS/FBS-r. Two meta-analytic studies show large effect sizes for FBS/FBS-r of similar magnitude.

CONCLUSIONS

FBS/FBS-r measures non-credible symptom report rather than legitimate experience of litigation stress. Importantly, the absence of significant FBS/FBS-r elevations in litigants who pass PVTs demonstrating credible performance, directly contradicts the contention of Nichols and Gass that the scale measures LRS. These data, meta-analytic publications, and recent test use surveys support the admissibility of FBS/FBS-r under both Daubert and the older Frye criteria.

PTSD in Court III: Malingering, assessment, and the law

This journal's third article on PTSD in Court focuses especially on the topic's "court" component. It first considers the topic of malingering, including in terms of its definition, certainties, and uncertainties. As with other areas of the study of psychological injury and law, generally, and PTSD (posttraumatic stress disorder), specifically, malingering is a contentious area not only definitionally but also empirically, in terms of establishing its base rate in the index populations assessed in the field. Both current research and re-analysis of past research indicates that the malingering prevalence rate at issue is more like 15±15% as opposed to 40±10%. As for psychological tests used to assess PTSD, some of the better ones include the TSI-2 (Trauma Symptom Inventory, Second Edition; Briere, 2011), the MMPI-2-RF (Minnesota Multiphasic Personality Inventory, Second Edition, Restructured Form; Ben-Porath & Tellegen, 2008/2011), and the CAPS-5 (The Clinician-Administered PTSD Scale for DSM-5; Weathers, Blake, Schnurr, Kaloupek, Marx, & Keane, 2013b). Assessors need to know their own possible biases, the applicable laws (e.g., the Daubert trilogy), and how to write court-admissible reports. Overall conclusions reflect a moderate approach that navigates the territory between the extreme plaintiff or defense allegiances one frequently encounters in this area of forensic practice.

Clinical neuropsychology practice and training in Canada

OBJECTIVE

This invited paper provides information about professional neuropsychology issues in Canada and is part of a special issue addressing international perspectives on education, training, and practice in clinical neuropsychology.

METHOD

Information was gathered from literature searches and personal communication with other neuropsychologists in Canada.

RESULTS

Canada has a rich neuropsychological history. Neuropsychologists typically have doctoral-level education including relevant coursework and supervised practical experience. Licensure requirements vary across the 10 provinces and there are regional differences in salary. While training at the graduate and internship level mirrors that of our American colleagues, completion of a two-year postdoctoral fellowship in neuropsychology is not required to obtain employment in many settings and there are few postdoctoral training programs in this country. The majority of neuropsychologists are employed in institutional settings (e.g. hospitals, universities, rehabilitation facilities), with a growing number entering private practice or other settings. There are challenges in providing neuropsychological services to the diverse Canadian population and a need for assessment measures and normative data in multiple languages.

CONCLUSIONS

Canadian neuropsychologists face important challenges in defining ourselves as distinct from other professions and other psychologists, in maintaining funding for high-quality training and research, in establishing neuropsychology-specific training and practice standards at the provincial or national level, and ensuring the clinical care that we provide is efficient and effective in meeting the needs of our patient populations and consumers, both within and outside of the publically funded health care system.

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.

The role of low cognitive effort and negative symptoms in neuropsychological impairment in schizophrenia

OBJECTIVE

Two experiments were conducted to examine whether insufficient effort, negative symptoms (e.g., avolition, anhedonia), and psychological variables (e.g., anhedonia and perception of low cognitive resources) predict generalized neurocognitive impairment in individuals with schizophrenia (SZ).

METHOD

In Experiment 1, participants included 97 individuals with SZ and 63 healthy controls (CN) who completed the Victoria Symptom Validity Test (VSVT), the MATRICS Consensus Cognitive Battery (MCCB), and self-report anhedonia questionnaires. In Experiment 2, participants included 46 individuals with SZ and 33 CN who completed Green's Word Memory Test (WMT), the MCCB, and self-reports of anhedonia, defeatist performance beliefs, and negative expectancy appraisals.

RESULTS

RESULTS indicated that a low proportion of individuals with SZ failed effort testing (1.0% Experiment 1; 15.2% Experiment 2); however, global neurocognitive impairment was significantly predicted by low effort and negative symptoms.

CONCLUSIONS

Findings indicate that low effort does not threaten the validity of neuropsychological test results in the majority of individuals with schizophrenia; however, effort testing may be useful in SZ patients with severe negative symptoms who may be more likely to put forth insufficient effort due to motivational problems. Although the base rate of failure is relatively low, it may be beneficial to screen for insufficient effort in SZ and exclude individuals who fail effort testing from pharmacological or cognitive remediation trials.

Simulation of Traumatic Brain Injury Symptoms on the Personality Assessment Inventory

The purpose of this study was to characterize the operating characteristics of the Personality Assessment Inventory (PAI) validity scales in distinguishing simulators feigning symptoms of traumatic brain injury (TBI) while completing the PAI ( n = 84) from a clinical sample of patients with TBI who achieved adequate scores on performance validity tests ( n = 112). The simulators were divided into two groups: (a) Specific Simulators feigning cognitive and somatic symptoms only or (b) Global Simulators feigning cognitive, somatic, and psychiatric symptoms. The PAI overreporting scales were indeed sensitive to the simulation of TBI symptoms in this analogue design. However, these scales were less sensitive to the feigning of somatic and cognitive TBI symptoms than the feigning of a broad range of cognitive, somatic, and emotional symptoms often associated with TBI. The relationships of TBI simulation to consistency and underreporting scales are also explored.

Creatine supplementation in fibromyalgia: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To investigate the efficacy and safety of creatine supplementation in fibromyalgia patients.

METHODS

A 16-week, randomized, double-blind, placebo-controlled, parallel-group trial was conducted. Fibromyalgia patients were randomly assigned to receive either creatine monohydrate or placebo in a double-blind manner. The patients were evaluated at baseline and after 16 weeks. Muscle function, aerobic conditioning, cognitive function, quality of sleep, quality of life, kidney function, and adverse events were assessed. Muscle phosphorylcreatine content was measured through (31) P magnetic resonance spectroscopy.

RESULTS

After the intervention, the creatine group presented higher muscle phosphorylcreatine content when compared with the placebo group (+80.3% versus -2.7%; P = 0.04). Furthermore, the creatine group presented greater muscle strength than the placebo group in the leg press and chest press exercises (+9.8% and +1.2% for creatine versus -0.5% and -7.2% for placebo, respectively; P = 0.02 and P = 0.002, respectively). Isometric strength was greater in the creatine group than in the placebo group (+6.4% versus -3.2%; P = 0.007). However, no general changes were observed in aerobic conditioning, pain, cognitive function, quality of sleep, and quality of life. Food intake remained unaltered and no side effects were reported.

CONCLUSION

Creatine supplementation increased intramuscular phosphorylcreatine content and improved lower- and upper-body muscle function, with minor changes in other fibromyalgia features. These findings introduce creatine supplementation as a useful dietary intervention to improve muscle function in fibromyalgia patients.

Working memory and intelligence are associated with victoria symptom validity test hard item performance in patients with intractable epilepsy

Loring et al. (Journal of clinical and experimental neuropsychology, 2005:27;610–617) observed relationships between VSVT hard item performance and IQ and memory indices in epilepsy surgical candidates, with a potential confound of low FSIQ on VSVT performance. The present study replicated the Loring et al. study in a larger sample and extended their findings by examining the relationships among VSVT performance, FSIQ, and working memory. A total of 404 patients with medically intractable epilepsy completed a comprehensive neuropsychological assessment. Differences in WAIS-III and WMS-III performance were examined as a function of VSVT hard score categories as determined by Grote et al. (2000)--that is, valid, > 20/24; questionable, 18–20; or invalid, < 18. Quantile regression models were constructed to compare the strength of the relationship between FSIQ and VSVT at various points of the FSIQ distribution. Linear regression analyses examined working memory as a potential mediator between FSIQ and VSVT performance. The invalid group performed more poorly than the valid and questionable groups on multiple measures of intelligence and memory. The strength of the relationship between FSIQ and VSVT hard item performance decreased as FSIQ increased, and working memory mediated this relationship. Results suggest VSVT hard item scores may be impacted by working memory difficulties and/or low intellectual functioning.

Auditory memory decrements, without dissimulation, among patients with major depressive disorder

Questions have been raised about whether poor performance on memory tasks by individuals with major depressive disorder (MDD) might be the result of poor or variable effort or disease-related disruption of neural circuits supporting memory functions. The present study examined performance on a measure of task engagement and on an auditory memory task among 45 patients with MDD (M age = 47.82, SD = 19.55) relative to 32 healthy controls (HC; M age = 51.03, SD = 22.09). One-hundred percent of HC and MDD volunteers performed above the threshold for adequate effort on a formal measure of task engagement. The MDD subjects performed significantly more poorly than the HC subjects on an auditory learning and memory test. The present results suggest that auditory memory difficulties do occur among those with MDD and that decrements in performance in this group may be related to factors other than lack of effort.

Neuropsychological evaluation of blast-related concussion: illustrating the challenges and complexities through OEF/OIF case studies

BACKGROUND/OBJECTIVE

Soldiers of Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF) sustain blast-related mild traumatic brain injury (concussion) with alarming regularity. This study discusses factors in addition to concussion, such as co-morbid psychological difficulty (e.g. post-traumatic stress) and symptom validity concerns that may complicate neuropsychological evaluation in the late stage of concussive injury.

CASE REPORT

The study presents the complexities that accompany neuropsychological evaluation of blast concussion through discussion of three case reports of OEF/OIF personnel.

DISCUSSION

The authors emphasize uniform assessment of blast concussion, the importance of determining concussion severity according to acute-injury characteristics and elaborate upon non-concussion-related factors that may impact course of cognitive limitation. The authors conclude with a discussion of the need for future research examining the impact of blast concussion (particularly recurrent concussion) and neuropsychological performance.