False-Positive Error Rates for Reliable Digit Span and Auditory Verbal Learning Test Performance Validity Measures in Amnestic Mild Cognitive Impairment and Early Alzheimer Disease

Modern scores for traditional tests - Review of the diagnostic potential of scores derived from word list learning tests in mild cognitive impairment and early Alzheimer's Disease

Episodic memory impairment is one of the early hallmarks in Alzheimer's Disease. In the clinical diagnosis and research, episodic memory impairment is typically assessed using word lists that are repeatedly presented to and recalled by the participant across several trials. Until recently, total learning scores, which consist of the total number of words that are recalled by participants, were almost exclusively used for diagnostic purposes. The present review aims at summarizing evidence on additional scores derived from the learning trials which have recently been investigated more frequently regarding their diagnostic potential. These scores reflect item acquisition, error frequencies, strategy use, intertrial fluctuations, and recall consistency. Evidence was summarized regarding the effects of clinical status on these scores. Preclinical, mild cognitive impairment and mild Alzheimer's Disease stages were associated with a pattern of reduced item acquisition, more errors, less strategy use, and reduced access of items, indicating slowed and erroneous encoding. Practical implications and limitations of the present research will be discussed.

Standalone Performance Validity Tests May Be Differentially Related to Measures of Working Memory, Processing Speed, and Verbal Memory in Patients With Multiple Sclerosis

Cognitive functioning may account for minimal levels (i.e., 5%-14%) of variance of performance validity test (PVT) scores in clinical examinees. The present study extended this research twofold: (a) by determining the variance cognitive functioning explains within three distinct PVTs (b) in a sample of patients with multiple sclerosis (pwMS). Seventy-five pwMS (Mage = 48.50, 70.6% female, 80.9% White) completed the Victoria Symptom Validity Test (VSVT), Word Choice Test (WCT), Dot Counting Test (DCT), and three objective measures of working memory, processing speed, and verbal memory as part of clinical neuropsychological assessment. Regression analyses in credible groups (ns ranged from 54 to 63) indicated that cognitive functioning explained 24% to 38% of the variance in logarithmically transformed PVT variables. Variance from cognitive testing differed across PVTs: verbal memory significantly influenced both VSVT and WCT scores; working memory influenced VSVT and DCT scores; and processing speed influenced DCT scores. The WCT appeared least related to cognitive functioning of the included PVTs. Alternative plausible explanations, including the apparent domain/modality specificity hypothesis of PVTs versus the potential sensitivity of these PVTs to neurocognitive dysfunction in pwMS were discussed. Continued psychometric investigations into factors affecting performance validity, especially in multiple sclerosis, are warranted.

Working Memory Precision and Associative Binding in Mild Cognitive Impairment

To better understand working memory (WM) deficits in Mild Cognitive Impairment (MCI), we examined information precision and associative binding in WM in 21 participants with MCI, compared to 16 healthy controls, using an item-location delayed reproduction task. WM, along with other executive functions (i.e. Trail Making Task (TMT) and Stroop task), were measured before and after a 2-h nap. The napping manipulation was intended as an exploratory element to this study exploring potential impacts of napping on executive functions.Compared to healthy participants, participants with MCI exhibited inferior performance not only in identifying encoded WM items but also on item-location associative binding and location precision even when only one item was involved. We also found changes on TMT and Stroop tasks in MCI, reflecting inferior attention and inhibitory control. Post-napping performance improved in most of these WM and other executive measures, both in MCI and their healthy peers.Our study shows that associative binding and WM precision can reliably differentiate MCIs from their healthy peers. Additionally, most measures showed no differential effect of group pre- and post-napping. These findings may contribute to better understanding cognitive deficits in MCI therefore improving the diagnosis of MCI.

Case study of invalid to valid shift in cognitive performance following successful treatment of psychogenic nonepileptic seizure events

Patients with psychogenic nonepileptic seizure (PNES) who fail performance validity testing (PVT) may appear to produce non-valid cognitive profiles. Consequently, they may not get referred to treatment and events persist, with worsening disability and high resource utilization. As a result, we report pre- and post-treatment neuropsychological evaluation findings in a 59-year-old woman with a confirmed diagnosis of PNES established using video-EEG monitoring. At pre-treatment baseline neuropsychological evaluation, PNES events occurred weekly to daily. Performance was impaired across PVTs and across multiple cognitive domains. After behavioral intervention specific to PNES, these events substantially reduced in frequency to rare stress-induced flares. Post-treatment neuropsychological evaluation revealed marked improvement of most cognitive and behavioral scores from baseline, and valid PVT scores. We review predisposing, precipitating, and perpetuating factors for PNES and cognitive impairment in this case and discuss the patient's outcome from treatment. Effectively managing PNES events and dissociative tendencies while reducing unnecessary pharmacological interventions appears to have allowed this patient to function closer to her optimal state. This case illustrates the complexity of Functional Neurologic Disorder (FND) clinical presentation and challenges the assumption that suboptimal neuropsychological performance predicts poor treatment engagement and outcome. We showcase the reversibility of PNES and cognitive manifestations of FND using targeted psychotherapeutic interventions, which resulted in reduced disability and associated healthcare costs, as well as re-engagement in life.

Optimal per test cutoff scores and combinations of failure on multiple embedded performance validity tests in detecting performance invalidity in a mixed clinical sample

We tested the usefulness of six embedded performance validity tests (EPVTs) in identifying performance invalidity in a mixed clinical sample. Using a retrospective design, 181 adults were classified as valid (n = 146) or invalid (n = 35) performance based upon their performance on one of three standalone PVTs (Test of Memory Malingering, Victoria Symptom Validity Test, Dot Counting Test). Multiple cutoffs were identified corresponding to predetermined false positive rates of 0, 5, 10, and 15% for each of six EPVTs. EPVT cutoffs corresponding to the predetermined false positive benchmarks were generally more conservative than currently established scores. Sensitivity was low (.0%-42.9%) for individual EPVTs across these cutoffs and was moderately improved by the combination of multiple EPVT failures. The optimal number of EPVT failures using the 10% false positive rate was ≥ 2. Although the overall classification accuracy of 80.7% and specificity of 89.0% were comparable to prior research, the sensitivity of 45.7% was more modest than previous estimates. Low sensitivities indicate that this combination of EPVTs failed to detect a majority of invalid performers.

Reliable Digit Span Scores Among Latin American Monolingual Spanish Speakers

OBJECTIVE

The Reliable Digit Span (RDS) is an embedded measure used to assess performance validity. The purpose of this study was to determine whether the RDS can be used with Spanish speakers from Latin America.

METHOD

The Digit Span subtest of the Wechsler Adult Intelligence Scale-IV was administered to 66 Spanish-speaking patients, 66 English-speaking patients, and 30 Spanish-speaking normal controls. The Spanish-speaking patients had a mean age of 65.82 (standard deviation [SD] = 12.44) and mean education of 6.62 years (SD = 4.91), whereas the controls had a mean age of 48.27 (SD = 10.97) and mean education of 8.33 (SD = 3.04). The English-speaking patients had a mean age of 56.44 (SD = 13.53) and mean education of 12.14 (SD = 2.37).

RESULTS

The average RDS among the Spanish-speaking patients was 5.36 (SD = 1.27) and the average RDS among the controls was 5.90 (SD = 1.06). The mean RDS of the English-speaking patients was 7.83 (SD = 1.72). The modal RDS among Spanish-speaking patients was 5. The modal RDS among Spanish-speaking controls was also 5, though the distribution was bimodal in nature with nearly as many 7 s as 5 s. The modal RDS among the English-speaking patients was 7. Among patients with ≥9 years of education and controlling for age, there remained a significant difference between both language patient groups on the RDS (F(1, 79) = 30.85, p < .0001).

CONCLUSIONS

These data suggest that the RDS may not be a valuable measure in assessing performance validity among monolingual Spanish speakers from Latin America, particularly among those with low levels of education.

Specificity of Embedded Performance Validity Tests in Elderly Veterans with Mild and Major Neurocognitive Disorder

OBJECTIVE

This study explored the specificity of four embedded performance validity tests (PVTs) derived from common neuropsychological tasks in a sample of older veterans with verified cognitive decline and whose performance was deemed valid by licensed psychologists.

METHOD

Participants were 180 veterans who underwent comprehensive neuropsychological evaluation, were determined to have valid performance following profile analysis/conceptualization, and were diagnosed with mild neurocognitive disorder (i.e., MCI; n = 64) or major neurocognitive disorder (i.e., Dementia; n = 116). All participants completed at least one of four embedded PVTs: Reliable Digit Span (RDS), California Verbal Learning Test-2nd ed. Short Form (CVLT-II SF) Forced choice, Trails B:A, and Delis-Kaplan Executive Function System (DKEFS) Letter and Category Fluency.

RESULTS

Adequate specificity (i.e., ≥90%) was achieved at modified cut-scores for all embedded PVTs across MCI and Dementia groups. Trails B:A demonstrated near perfect specificity at its traditional cut-score (Trails B:A < 1.5). RDS ≤ 5 and CVLT-II SF Forced Choice ≤7 led to <10% false positive classification errors across MCI and dementia groups. DKEFS Letter and Category Fluency achieved 90% specificity at extremely low normative cut-scores.

CONCLUSIONS

RDS, Trails B:A, and CVLT-II SF Forced Choice reflect promising embedded PVTs in the context of dementia evaluations. DKEFS Letter and Category Fluency appear too sensitive to genuine neurocognitive decline and, therefore, are inappropriate PVTs in adults with MCI or dementia. Additional research into embedded PVT sensitivity (via known-groups or analogue designs) in MCI and dementia is needed.

Racial differences in positive findings on embedded performance validity tests

INTRODUCTION

Embedded performance validity tests (PVTs) may show increased positive findings in racially diverse examinees. This study examined positive findings in an older adult sample of African American (AA) and European American (EA) individuals recruited as part of a study on aging and cognition.

METHOD

The project involved secondary analysis of deidentified National Alzheimer's Coordinating Center data (N = 22,688). Exclusion criteria included diagnosis of dementia (n = 5,550), mild cognitive impairment (MCI; n = 5,160), impaired but not MCI (n = 1,126), other race (n = 864), and abnormal Mini Mental State Examination (MMSE < 25; n = 135). The initial sample included 9,853 participants (16.4% AA). Propensity score matching matched AA and EA participants on age, education, sex, and MMSE score. The final sample included 3,024 individuals with 50% of participants identifying as AA. Premorbid ability estimates were calculated based on demographics. Failure rates on five raw score and six age-adjusted scaled score PVTs were examined by race.

RESULTS

Age, education, sex, MMSE, and premorbid ability estimate were not significantly different by race. Thirteen percent of AA and 3.8% of EA participants failed two or more raw score PVTs (p < .0001). On age-adjusted PVTs, 20.6% of AA and 5.9% of EA participants failed two or more (p < .0001).

CONCLUSIONS

PVT failure rates were significantly higher among AA participants. Findings indicate a need for cautious interpretation of embedded PVTs with underrepresented groups. Adjustments to embedded PVT cutoffs may need to be considered to improve diagnostic accuracy.

A Direct Comparison of 10 WAIS-IV Digit Span Embedded Validity Indicators among a Mixed Neuropsychiatric Sample with Varying Degrees of Cognitive Impairment

Objective

Reliable Digit Span (RDS), RDS-Revised (RDS-R), and age-corrected scaled score (ACSS) have been previously validated as embedded performance validity tests (PVTs) from the Wechsler Adult Intelligence Scale-IV Digit Span subtest (WAIS-IV DS). However, few studies have directly compared the relative utility of these and other proposed WAIS-IV DS validity indicators within a single sample.

Method

This study compared classification accuracies of 10 WAIS-IV DS indices in a mixed neuropsychiatric sample of 227 outpatients who completed a standardized neuropsychological battery. Participants with ≤1 PVT failures of the four, freestanding criterion PVTs constituted the valid group (n = 181), whereas those with ≥2 PVT failures formed the invalid group (n = 46). Among the valid group, 113 met criteria for mild cognitive impairment (MCI).

Results

Classification accuracies for all DS indicators were statistically significant across the overall sample and subsamples with and without MCI, apart from indices derived from the Forward trial in the MCI sample. DS Sequencing ACSS, working memory RDS (wmRDS), and DS ACSS emerged as the most effective predictors of validity status, with acceptable to excellent classification accuracy for the overall sample (AUCs = 0.792–0.816; 35%–50% sensitivity/88%–96% specificity).

Conclusions

Although most DS indices demonstrated clinical utility as embedded PVTs, DS Sequencing ACSS, wmRDS, and DS ACSS may be particularly robust to cognitive impairment, minimizing risk of false positive errors while identifying noncredible performance. Moreover, DS indices incorporating data from multiple trials (i.e., wmRDS, DS ACSS) also generally yielded greater classification accuracy than those derived from a single trial.

Considerations for Reliable Digit Span as a performance validity test for long-term survivors of childhood brain tumors

The Reliable Digit Span (RDS) is a performance validity test (PVT) used widely within non-clinical samples, but its utility is in question in clinical groups with cognitive impairment. To investigate, RDS scores were calculated and correlated with the Neurological Predictor Scale, an informant-reported Activities of Daily Living score, and a proxy measure of intelligence (Vocabulary) for 83 adult survivors of childhood brain tumors and 105 healthy controls. Analyses were covaried for age at examination. Participants were divided into passing and failing groups at each RDS cutoff, and ANCOVAs for each of the three variables of interest covaried for age at the examination were run. RDS was correlated with all three variables of interest in survivors but only Vocabulary in controls. At the ≤7 cutoff, passing and failing survivors demonstrated significant differences across all variables of interest, while passing and failing controls differed only on Vocabulary. Differences were also found between passing and failing survivors at lower cutoffs. RDS is related to and likely impacted by various neurological and cognitive challenges faced by brain tumor survivors. Using the standard RDS cutoff of ≤7 may result in inaccurate interpretation of valid performance in this population; therefore, the use of other PVTs is recommended.

Evaluation of the classification accuracy of multiple performance validity tests in a mixed clinical sample

The Test of Memory Malingering (TOMM) and Word Memory Test (WMT) are among the most well-known performance validity tests (PVTs) and regarded as gold standard measures. Due to the many factors that impact PVT selection, it is imperative that clinicians make informed clinical decisions with respect to additional or alternative PVTs that demonstrate similar classification accuracy as these well-validated measures. The present archival study evaluated the agreement/classification accuracy of a large battery consisting of multiple other freestanding/embedded PVTs in a mixed clinical sample of 126 veterans. We examined failure rates for all standalone/embedded PVTs using established cut-scores and calculated pass/fail agreement rates and diagnostic odds ratios for various combinations of PVTs using the TOMM and WMT as criterion measures. TOMM and WMT demonstrated the best agreement, followed by Word Choice Test (WCT). The Rey Fifteen Item Test had an excessive number of false-negative errors and reduced classification accuracy. The Digit Span age-corrected scaled score (DS-ACSS) had highest agreement. Findings lend further support to the use of a combination of embedded and standalone PVTs in identifying suboptimal performance. Results provide data to enhance clinical decision making for neuropsychologists who implement combinations of PVTs in a larger clinical battery.

Clinical Neuropsychological Evaluation in Older Adults With Major Depressive Disorder

PURPOSE OF THE REVIEW

Older adults with major depressive disorder are particularly vulnerable to MDD-associated adverse cognitive effects including slowed processing speed, decreased attention, and executive dysfunction. The purpose of this review is to describe the approach to a clinical neuropsychological evaluation in older adults with MDD. Specifically, this review compares and contrasts neurocognitive screening and clinical neuropsychological evaluation procedures and details the multiple components of the clinical neuropsychological evaluation.

RECENT FINDINGS

Research has shown that neurocognitive screening serves a useful purpose to provide an acute and rapid assessment of global cognitive function; however, it has limited sensitivity and specificity. The clinical neuropsychological evaluation process is multifaceted and encompasses a review of available medical records, neurobehavioral status and diagnostic interview, comprehensive cognitive and clinical assessment, examination of inclusion and diversity factors as well as symptom and performance validity, and therapeutic feedback. As such, the evaluation provides invaluable information on multiple cognitive functions, establishes brain and behavior relationships, clarifies neuropsychiatric diagnoses, and can inform the etiology of cognitive impairment. Clinical neuropsychological evaluation plays a unique and critical role in integrated healthcare for older adults with MDD. Indeed, the evaluation can serve as a nexus to synthesize information across healthcare providers in order to maximize measurement-based care that can optimize personalized medicine and overall health outcomes.

Psychometric implications of failure on one performance validity test: a cross-validation study to inform criterion group definition

Introduction: Research to date has supported the use of multiple performance validity tests (PVTs) for determining validity status in clinical settings. However, the implications of including versus excluding patients failing one PVT remains a source of debate, and methodological guidelines for PVT research are lacking. This study evaluated three validity classification approaches (i.e. 0 vs. ≥2, 0-1 vs. ≥2, and 0 vs. ≥1 PVT failures) using three reference standards (i.e. criterion PVT groupings) to recommend approaches best suited to establishing validity groups in PVT research methodology.Method: A mixed clinical sample of 157 patients was administered freestanding (Medical Symptom Validity Test, Dot Counting Test, Test of Memory Malingering, Word Choice Test), and embedded PVTs (Reliable Digit Span, RAVLT Effort Score, Stroop Word Reading, BVMT-R Recognition Discrimination) during outpatient neuropsychological evaluation. Three reference standards (i.e. two freestanding and three embedded PVTs from the above list) were created. Rey 15-Item Test and RAVLT Forced Choice were used solely as outcome measures in addition to two freestanding PVTs not employed in the reference standard. Receiver operating characteristic curve analyses evaluated classification accuracy using the three validity classification approaches for each reference standard.Results: When patients failing only one PVT were excluded or classified as valid, classification accuracy ranged from acceptable to excellent. However, classification accuracy was poor to acceptable when patients failing one PVT were classified as invalid. Sensitivity/specificity across two of the validity classification approaches (0 vs. ≥2; 0-1 vs. ≥2) remained reasonably stable.Conclusions: These results reflect that both inclusion and exclusion of patients failing one PVT are acceptable approaches to PVT research methodology and the choice of method likely depends on the study rationale. However, including such patients in the invalid group yields unacceptably poor classification accuracy across a number of psychometrically robust outcome measures and therefore is not recommended.

The Analysis of Oxidative Stress Markers May Increase the Accuracy of the Differential Diagnosis of Alzheimer's Disease with and without Depression

Introduction

The aim of work is to assess the usefulness of oxidative stress parameters in the differential diagnosis of dementia of the Alzheimer’s type and dementia of the Alzheimer’s type with coexisting depression.

Methods

The study involved three groups of people: patients with Alzheimer’s disease (AD) (AD; N=27), patients with Alzheimer’s disease and depression (D) (AD+D; N=30), and a control group that consisted of people without dementia and without depression (C; N=24). The assessment of cognitive functioning was carried out using among alia, Auditory Verbal Learning Test and Verbal Fluency Test. Furthermore, we determined the activity of superoxide dismutase (SOD-1) and superoxide anion radical.

Results

Multiple models with different combinations of independent variables showed that SOD together with Rey delayed recall were the best significant predictors of AD with the area under curve (AUC) of 0.893 (p = 0.001) and superoxide anion radical (O2^•−) together with verbal fluency – sharp objects were the best significant predictors of AD +D diagnosis with the AUC of 0.689 (p = 0.034).

Conclusion

This study confirmed the value of neuropsychological diagnosis and analysis of oxidative stress markers in the diagnosis of AD and major depressive disorder (MDD) in the course of AD. The combination of the use of biochemical markers and neuropsychological tests seems particularly important for differential diagnosis.

American Academy of Clinical Neuropsychology (AACN) 2021 consensus statement on validity assessment: Update of the 2009 AACN consensus conference statement on neuropsychological assessment of effort, response bias, and malingering

Objective: Citation and download data pertaining to the 2009 AACN consensus statement on validity assessment indicated that the topic maintained high interest in subsequent years, during which key terminology evolved and relevant empirical research proliferated. With a general goal of providing current guidance to the clinical neuropsychology community regarding this important topic, the specific update goals were to: identify current key definitions of terms relevant to validity assessment; learn what experts believe should be reaffirmed from the original consensus paper, as well as new consensus points; and incorporate the latest recommendations regarding the use of validity testing, as well as current application of the term 'malingering.' Methods: In the spring of 2019, four of the original 2009 work group chairs and additional experts for each work group were impaneled. A total of 20 individuals shared ideas and writing drafts until reaching consensus on January 21, 2021. Results: Consensus was reached regarding affirmation of prior salient points that continue to garner clinical and scientific support, as well as creation of new points. The resulting consensus statement addresses definitions and differential diagnosis, performance and symptom validity assessment, and research design and statistical issues. Conclusions/Importance: In order to provide bases for diagnoses and interpretations, the current consensus is that all clinical and forensic evaluations must proactively address the degree to which results of neuropsychological and psychological testing are valid. There is a strong and continually-growing evidence-based literature on which practitioners can confidently base their judgments regarding the selection and interpretation of validity measures.

A Known-Groups Validation of the Medical Symptom Validity Test and Analysis of the Genuine Memory Impairment Profile

This study cross-validated the Medical Symptom Validity Test (MSVT) in a mixed neuropsychiatric sample and examined its accuracy for identifying invalid neuropsychological performance using a known-groups design. Cross-sectional data from 129 clinical patients who completed the MSVT were examined. Validity groups were established using six, independent criterion performance validity tests, which yielded 98 patients in the valid group and 31 in the invalid group. All MSVT subtest scores were significantly lower in the invalid group (η p2=.22-.39). Using published cut-scores, sensitivities of 42% to 71% were found among the primary effort subtests, and 74% sensitivity/90% specificity was observed for the overall MSVT. Among this sample, the MSVT component validity scales produced areas under the curve of .78-.86, suggesting moderate classification accuracy. At optimal cut-scores, the MSVT primary effort validity scales demonstrated 55% to 71% sensitivity/91% to 93% specificity, with the Consistency subtest exhibiting the strongest psychometric properties. The MSVT exhibited relatively robust sensitivity and specificity, supporting its utility as a briefer freestanding performance validity test to its predecessor, the Word Memory Test. Finally, the Genuine Memory Impairment Profile appears promising for patients with Major Neurocognitive Disorder, but is cautioned against for those without significant functional decline in activities of daily living at this time.

Delayed matching to sample task 48: assessment of malingering with simulating design

The results of neuropsychological tests may be distorted by patients who exaggerate cognitive deficits. Eighty-three patients with cognitive deficit [Amnestic Mild Cognitive Impairment (aMCI), n = 53; Alzheimer's disease (AD) dementia, n = 30], 44 healthy older adults (HA), and 30 simulators of AD (s-AD) underwent comprehensive neuropsychological assessment. Receiver Operating Characteristic (ROC) analysis revealed high specificity but low sensitivity of the Delayed Matching to Sample Task (DMS48) in differentiating s-AD from AD dementia (87 and 53%, respectively) and from aMCI (96 and 57%). The sensitivity was considerably increased by using the DMS48/Rey Auditory Verbal Learning Test (RAVLT) ratio (specificity and sensitivity 93% and 93% for AD dementia and 96% and 80% for aMCI). The DMS48 differentiates s-AD from both aMCI and AD dementia with high specificity but low sensitivity. Its predictive value greatly increased when evaluated together with the RAVLT.

Performance validity test failure in clinical populations-a systematic review

Performance validity tests (PVTs) are widely used in attempts to quantify effort and/or detect negative response bias during neuropsychological testing. However, it can be challenging to interpret the meaning of poor PVT performance in a clinical context. Compensation-seeking populations predominate in the PVT literature. We aimed to establish base rates of PVT failure in clinical populations without known external motivation to underperform. We searched MEDLINE, EMBASE and PsycINFO for studies reporting PVT failure rates in adults with defined clinical diagnoses, excluding studies of active or veteran military personnel, forensic populations or studies of participants known to be litigating or seeking disability benefits. Results were summarised by diagnostic group and implications discussed. Our review identified 69 studies, and 45 different PVTs or indices, in clinical populations with intellectual disability, degenerative brain disease, brain injury, psychiatric disorders, functional disorders and epilepsy. Various pass/fail cut-off scores were described. PVT failure was common in all clinical groups described, with failure rates for some groups and tests exceeding 25%. PVT failure is common across a range of clinical conditions, even in the absence of obvious incentive to underperform. Failure rates are no higher in functional disorders than in other clinical conditions. As PVT failure indicates invalidity of other attempted neuropsychological tests, the finding of frequent and unexpected failure in a range of clinical conditions raises important questions about the degree of objectivity afforded to neuropsychological tests in clinical practice and research.

Performance and Symptom Validity Assessment in Patients with Apathy and Cognitive Impairment

OBJECTIVE

Performance and symptom validity tests (PVTs and SVTs) measure the credibility of the assessment results. Cognitive impairment and apathy potentially interfere with validity test performance and may thus lead to an incorrect (i.e., false-positive) classification of the patient's scores as non-credible. The study aimed at examining the false-positive rate of three validity tests in patients with cognitive impairment and apathy.

METHODS

A cross-sectional, comparative study was performed in 56 patients with dementia, 41 patients with mild cognitive impairment, and 41 patients with Parkinson's disease. Two PVTs - the Test of Memory Malingering (TOMM) and the Dot Counting Test (DCT) - and one SVT - the Structured Inventory of Malingered Symptomatology (SIMS) - were administered. Apathy was measured with the Apathy Evaluation Scale, and severity of cognitive impairment with the Mini Mental State Examination.

RESULTS

The failure rate was 13.7% for the TOMM, 23.8% for the DCT, and 12.5% for the SIMS. Of the patients with data on all three tests (n = 105), 13.5% failed one test, 2.9% failed two tests, and none failed all three. Failing the PVTs was associated with cognitive impairment, but not with apathy. Failing the SVT was related to apathy, but not to cognitive impairment.

CONCLUSIONS

In patients with cognitive impairment or apathy, failing one validity test is not uncommon. Validity tests are differentially sensitive to cognitive impairment and apathy. However, the rule that at least two validity tests should be failed to identify non-credibility seemed to ensure a high percentage of correct classification of credibility.

They're not just little adults: The utility of adult performance validity measures in a mixed clinical pediatric sample

Performance validity tests (PVTs) have become a standard part of adult neuropsychological practice; however, they are less widely used in pediatric testing. The current study aimed to obtain a better understanding of the application of PVTs within a mixed clinical pediatric sample with a wide range of diagnosis, IQ, and age. Cross-sectional data were analyzed from 130 consecutive pediatric patients evaluated as part of clinical care and diagnosed with a variety of medical/neurological, developmental, and psychiatric disorders. Patients were administered a battery of neuropsychological tests; results of intellectual functioning measures (i.e., Wechsler Intelligence Scale for Children-Fifth Edition [WISC-V] or Wechsler Adult Intelligence Scale-Fourth Edition [WAIS-IV]), and PVTs (i.e., Test of Memory Malingering [TOMM] and Digit Span [DS] subtests of the WISC-V/WAIS-IV) were analyzed to assess PVT performance across the sample as well as age- and Full-Scale IQ-related (FSIQ) effects on pass rate. Results suggested that the TOMM is an effective validity test for youth, as the TOMM adult cutoff score was also valid for children (88% pass rate on TOMM trial 1 cut-score ≥41, 71% pass rate on TOMM trial 1 cut-score ≥45). In contrast, Reliable Digit Span (RDS) was less accurate (34% failed RDS [cut-score ≤6], 54% failed RDS-r [cut-score ≤10], and 25% failed DS ACSS [cut-score ≤5]) using standard adult cutoffs. Notably, although TOMM scores were not strongly influenced by IQ, DS scores increased as IQ increased. Overall, further analysis of PVTs can champion new standards of practice through additional research establishing PVT accuracy within pediatric populations.

Preliminary Validation of the Rey 15-Item Test and Reliable Digit Span in Native Japanese Samples

The Rey 15-Item Test and reliable digit span were evaluated in Japan. Participants were controls ( n = 15), healthy volunteers instructed to simulate memory impairment ( n = 12; 5 of 17 volunteers did not comply with instructions and were dropped), healthy elderly ( n = 12), and cognitively disabled nursing home residents ( n = 8). On the 15-Item Test, controls and elderly performed similarly and were combined. Nursing home residents could not cope with the 15-Item Test and were dropped. Total score was a fair predictor of dissimulation using a cutoff ≤ 8. Rows were fair predictors using a ≤2 cutoff. Sensitivities were low and specificities were excellent. Reliable digit span contrasts between simulators and each of the other groups demonstrated that reliable digit span discriminated controls and elderly from simulators (≤6 and ≤5 cutoffs). Sensitivities were moderate and specificities were excellent. Reliable digit span did not differentiate simulators from nursing home residents.

If Invalid PVT Scores Are Obtained, Can Valid Neuropsychological Profiles Be Believed?

Background

Performance Validity Testing (PVT) decision-making rules may be indeterminate in patients with neurological disease in which PVT characteristics have not been adequately studied. We report a patient with multiple sclerosis (MS) who failed computerized PVT testing but had normal memory scores with a neuropsychological profile consistent with expected MS disease-related weaknesses.

Method

Neuropsychological testing was conducted on two occasions in a middle-aged woman with an established MS diagnosis to address concerns of possible memory decline. Testing was discontinued after PVT scores below recommended cut-points were obtained during the first evaluation. During the second assessment, subthreshold PVT scores on a different computerized PVT were obtained, but unlike the first assessment, the entire neuropsychological protocol was administered.

Results

Despite subthreshold computerized PVT scores, normal learning and memory performance was obtained providing objective data to answer the referral question. Other neuropsychological findings included decreased processing speed, poor working memory, and poor executive function consistent with her MS diagnosis. Embedded PVT scores were normal.

Conclusions

We speculate that poor computerized PVT scores resulted from the disease-related features of MS, although we also discuss approaches to reconcile apparently contradictory PVT versus neuropsychological results if the contributions of disease-related variables on PVTs scores are discounted. This case demonstrates the value of completing the assessment protocol despite obtaining PVT scores below publisher recommended cutoffs in clinical evaluations. If subthreshold PVT scores are considered evidence of performance invalidity, it is still necessary to have an approach for interpreting seemingly credible neuropsychological test results rather than simply dismissing them as invalid.

Symptom and performance validation in patients with subjective cognitive decline and mild cognitive impairment

Nonauthentic symptom claims (overreporting) and invalid test results (underperformance) can regularly be expected in a forensic context, but may also occur in clinical referrals. While the applicability of symptom and performance validity tests in samples of dementia patients is well studied, the same is not true for patients with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). A sample of 54 memory-clinic outpatients with evidence of SCD or MCI was studied. We evaluated the rate of positive results in three validity measures. A total of 7.4% of the patients showed probable negative response bias in the Word Memory Test. The rate of positive results on the Structured Inventory of Malingered Symptomatology was 14.8% while only one participant (1.9%) scored positive on the Self-Report Symptom Inventory using the standard cutoff. The two questionnaires were moderately correlated at .67. In a combined analysis of all results, five of the patients (9.3%) were judged to show evidence of probable negative response bias (or probably feigned neurocognitive impairment). In the current study, a relatively small but nontrivial rate of probable response distortions was found in a memory-clinic sample. However, it remains a methodological challenge for this kind of research to reliably distinguish between false-positive and correct-positive classifications in clinical patient groups.

Effort Testing in Dementia Assessment: A Systematic Review

Objective

Interpretation of neuropsychological test data is only valid when appropriate effort has been exerted. Research, however, suggests that neuropsychologists do not always formally test for effort and that this may especially be the case in the context of dementia assessment. This review systematically examined the literature that has investigated the use of both purpose-built and embedded effort-sensitive indices in dementia, mild cognitive impairment (MCI), and healthy control samples. The aim was to determine which tests of effort are most sensitive to suboptimal effort and least sensitive to the type of cognitive impairment seen in dementia.

Methods

A systematic search of databases was conducted to October 2017. There was no start date.

Results

Twenty-five studies were included for review. The studies were divided into two categories according to methodology. One category of studies (n = 5) was reviewed using a tailored methodological quality rating checklist whilst the remaining studies (n = 20) were reviewed using the Crowe Critical Appraisal Tool (CCAT).

Conclusions

The results of this review suggest that PVTs which take a hierarchical approach to effort testing such as the WMT, MSVT, and NV-MSVT are preferable for use with older adults who are under investigation for possible dementia. These tests go above and beyond the traditional pass/fail approach of more traditional tests of effort because they allow the examiner to analyze the examinee's profile of scores. The methodological limitations and challenges involved in this field of research are discussed.

Short-term adverse effects of the apolipoprotein E ε4 allele over language function and executive function in healthy older adults

Background: The 4 allele of the apolipoprotein E (APOE) gene is known as a risk factor for cognitive impairment. How APOE ε polymorphism affects the language and executive functions of healthy aging subjects remains less clear. Purpose: In this follow-up study, the relationship between APOE status and cognitive performance across various cognitive domains in healthy individuals (without dementia or mild cognitive impairment (MCI)) over 60 years old was investigated. Patients and methods: Based on multiplex amplification refractory mutation system polymerase chain reaction (PCR), 228 subjects (n=228; mean age: 70.59±8.07 years old; male %=40.8%) were divided into three groups, e2 (ε2/ε2 and ε2/ε3, n=35), e3 (ε3/ε3, n=152), and e4 (ε2/ε4, ε3/ε4, and ε4/ε4, n=41). Results: There was no statistical difference (p>0.05) in the general demographic data and neuropsychological tests among the three groups on the baseline; however, e4 group showed a greater drop rate (p<0.05) versus non-carriers on verbal fluency (e2: -0.043±0.221; e3: -0.081±0.239; e4: 0.069±0.329) and Webster picture completion (e2: 0.055±0.281; e3: 0.083±0.428; e4: 0.438±1.280) over the subsequent one year. Conclusion: The findings suggest that possession of the APOE ε4 allele predicted a higher decline on tasks of language function and executive function in healthy elderly. And further research is required to determine whether strengthening the training of language function and executive function will delay the occurrence of cognitive impairment.

Performance validity in older adults: Observed versus predicted false positive rates in relation to number of tests administered

INTRODUCTION

This study examined false positive rates on embedded performance validity tests (PVTs) in older adults grouped by cognitive status.

METHOD

The research design involved secondary analysis of data from the National Alzheimer's Coordinating Center database. Participants (N = 22,688) were grouped by cognitive status: normal (n = 10,319), impaired (n = 1,194), amnestic or nonamnestic mild cognitive impairment (MCI; n = 5,414), and dementia (n = 5,761). Neuropsychological data were used to derive 5 PVTs.

RESULTS

False positive rates on individual PVTs ranged from 3.3 to 26.3% with several embedded PVTs showing acceptable specificity across groups. The proportion of participants failing two or more PVTs varied by cognitive status: normal (1.9%), impaired (6.6%), MCI (13.2%), and dementia (52.8%). Comparison of observed and predicted false positive rates at different specificity levels (.85 or .90) demonstrated significant differences in all comparisons. In normal and impaired groups, predicted rates were higher than observed rates. In the MCI group, predicted and observed comparisons varied: Predicted rates were higher with specificity at .85 and lower with specificity at .90. In the dementia group, predicted rates underestimated observed rates.

CONCLUSIONS

Despite elevated false positives in conditions involving severe cognitive compromise, several measures retain acceptable specificity regardless of cognitive status. Predicted false positive rates based on the number of PVTs administered were not observed empirically. These findings do not support the utility of simulated data in predicting false positive rates in older adults.

Convergent, Discriminant, and Concurrent Validity of Nonmemory-Based Performance Validity Tests

To supplement memory-based Performance Validity Tests (PVTs) in identifying noncredible performance, we examined the validity of the two most commonly used nonmemory-based PVTs—Dot Counting Test (DCT) and Wechsler Adult Intelligence Scale–Fourth edition (WAIS-IV) Reliable Digit Span (RDS)—as well as two alternative WAIS-IV Digit Span (DS) subtest PVTs. Examinees completed DCT, WAIS-IV DS, and the following criterion PVTs: Test of Memory Malingering, Word Memory Test, and Word Choice Test. Validity groups were determined by passing 3 (valid; n = 69) or failing ⩾2 (noncredible; n = 30) criterion PVTs. DCT, RDS, RDS–Revised (RDS-R), and WAIS-IV DS Age-Corrected Scaled Score (ACSS) were significantly correlated (but uncorrelated with memory-based PVTs). Combining RDS, RDS-R, and ACSS with DCT improved classification accuracy (particularly for DCT/ACSS) for detecting noncredible performance among valid-unimpaired, but largely not valid-impaired examinees. Combining DCT with ACSS may uniquely assess and best supplement memory-based PVTs to identify noncredible neuropsychological test performance in cognitively unimpaired examinees.

Comparing two models of performance validity assessment in patients with Parkinson's disease who are candidates for deep brain stimulation surgery

Utility of standalone and embedded performance validity tests (PVTs) as well as the decision-making algorithms used to reach clinical conclusions about credible and noncredible performance can be population specific. To better understand PVT utility in Parkinson's disease candidates for deep brain stimulation (DBS) we present on two aims: 1) establishing the frequency data of below-criterion responding for the Medical Symptom Validity Test and three embedded PVTs in a sample of 47 patients with Parkinson's disease, and 2) comparing the efficacy of two models for clinical-decision making regarding noncredible performance. Consistent with expectations from previous studies and desired specificity values, our retrospective analysis indicated that in this sample of presumably well-motived patients, the rate of below-criterion responding was less than 10% for all PVTs administered. Regarding our model comparison, we compared a typical PVT battery that required administration of a standalone measure in all cases against a recently proposed low risk algorithm that attempts to lower testing burden by relying more heavily on embedded PVTs with administration of a standalone measure only in the event of below-criterion performance on an embedded indicator. Results suggest that for patients with Parkinson's disease judged to be at limited risk for noncredible performance, a low risk PVT model may prove both more efficient and less prone to error than a more typical model. Implications for clinical decision-making are discussed, as are limitations of the study and its generalizability.

Research methods in performance validity testing studies: Criterion grouping approach impacts study outcomes

OBJECTIVE

Performance validity test (PVT) research studies commonly utilize a known-groups design, but the criterion grouping approaches within the design vary greatly from one study to another. At the present time, it is unclear as to what degree different criterion grouping approaches might impact PVT classification accuracy statistics.

METHOD

To analyze this, the authors used three different criterion grouping approaches to examine how classification accuracy statistics of a PVT (Word Choice Test; WCT) would differ. The three criterion grouping approaches included: (1) failure of 2+ PVTs versus failure of 0 PVTs, (2) failure of 2+ PVTs versus failure of 0-1 PVT, and (3) failure of a stand-alone PVT versus passing of a stand-alone PVT (Test of Memory Malingering).

RESULTS

When setting specificity at ≥.90, WCT cutoff scores ranged from 41 to 44 and associated sensitivity values ranged from .64 to .88, depending on the criterion grouping approach that was utilized.

CONCLUSIONS

When using a stand-alone PVT to define criterion group status, classification accuracy rates of the WCT were higher than expected, likely due to strong correlations between the reference PVT and the WCT. This held true even when considering evidence that this grouping approach results in higher rates of criterion group misclassification. Conversely, when using criterion grouping approaches that utilized failure of 2+ PVTs, accuracy rates were more consistent with expectations. These findings demonstrate that criterion grouping approaches can impact PVT classification accuracy rates and resultant cutoff scores. Strengths, weaknesses, and practical implications of each of the criterion grouping approaches are discussed.

Temporal Order of Alzheimer's Disease-Related Cognitive Marker Changes in BLSA and WRAP Longitudinal Studies

Investigation of the temporal trajectories of currently used neuropsychological tests is critical to identifying earliest changing measures on the path to dementia due to Alzheimer's disease (AD). We used the Progression Score (PS) method to characterize the temporal trajectories of measures of verbal memory, executive function, attention, processing speed, language, and mental status using data spanning normal cognition, mild cognitive impairment, and AD from 1,661 participants with a total of 7,839 visits (age at last visit 77.6 SD 9.2) in the Baltimore Longitudinal Study of Aging (BLSA) and 1510 participants with a total of 3,473 visits (age at last visit 59.5 SD 7.4) in the Wisconsin Registry for Alzheimer's Prevention (WRAP). This method aligns individuals in time based on the similarity of their longitudinal measurements to reveal temporal trajectories. As a validation of our methodology, we explored the associations between the individualized cognitive progression scores (Cog-PS) computed by our method and clinical diagnosis. Digit span tests were the first to show declines in both data sets, and were detected mainly among cognitively normal individuals. These were followed by tests of verbal memory, which were in turn followed by Trail Making Tests, Boston Naming Test, and Mini-Mental State Examination. Differences in Cog-PS across the clinical diagnosis and APOEɛ4 groups were statistically significant, highlighting the potential use of Cog-PS as individualized indicators of disease progression. Identifying cognitive measures that are changing in preclinical AD can lead to the development of novel cognitive tests that are finely tuned to detecting earliest changes.

Meta-Analysis of Parkinson's Disease and Alzheimer's Disease Revealed Commonly Impaired Pathways and Dysregulation of NRF2-Dependent Genes

Many lines of evidence suggest that Parkinson's disease (PD) and Alzheimer's disease (AD) have common characteristics, such as mitochondrial dysfunction and oxidative stress. As the underlying molecular mechanisms are unclear, we perform a meta-analysis with 9 microarray datasets of PD studies and 7 of AD studies to explore it. Functional enrichment analysis revealed that PD and AD both showed dysfunction in the synaptic vesicle cycle, GABAergic synapses, phagosomes, oxidative phosphorylation, and TCA cycle pathways, and AD had more enriched genes. Comparing the differentially expressed genes between AD and PD, we identified 54 common genes shared by more than six tissues. Among them, 31 downregulated genes contained the antioxidant response element (ARE) consensus sequence bound by NRF2. NRF2 is a transcription factor, which protects cells against oxidative stress through coordinated upregulation of ARE-driven genes. To our surprise, although NRF2 was upregulated, its target genes were all downregulated. Further exploration found that MAFF was upregulated in all tissues and significantly negatively correlated with the 31 NRF2-dependent genes in diseased conditions. Previous studies have demonstrated over-expressed small MAFs can form homodimers and act as transcriptional repressors. Therefore, MAFF might play an important role in dysfunction of NRF2 regulatory network in PD and AD.

Targeting psychologic stress signaling pathways in Alzheimer's disease

Alzheimer's Disease (AD) is the most prevalent progressive neurodegenerative disease; to date, no AD therapy has proven effective in delaying or preventing the disease course. In the search for novel therapeutic targets in AD, it has been shown that increased chronic psychologic stress is associated with AD risk. Subsequently, biologic pathways underlying psychologic stress have been identified and shown to be able to exacerbate AD relevant pathologies. In this review, we summarize the literature relevant to the association between psychologic stress and AD, focusing on studies investigating the effects of stress paradigms on transgenic mouse models of Amyloid-β (Aβ) and tau pathologies. In recent years, a substantial amount of research has been done investigating a key stress-response mediator, corticotropin-releasing hormone (CRH), and its interactions with AD relevant processes. We highlight attempts to target the CRH signaling pathway as a therapeutic intervention in these transgenic mouse models and discuss how targeting this pathway is a promising avenue for further investigation.