Dustin B. Hammers

The relationship of malingering test failure to self-reported symptoms and neuropsychological findings in adults referred for ADHD evaluation

Diagnosis of adult attention-deficit/hyperactivity disorder (ADHD) adults is difficult, as neither symptom report nor neuropsychological findings are specific to ADHD. Few studies address the possibility that noncredible performance influences both symptom report and neuropsychological findings. The present study utilized archival data from young adults referred for concerns about ADHD, divided into three groups: (1) those who failed a measure of noncredible performance (the Word Memory Test; WMT), (2) those who met diagnostic criteria for ADHD, and (3) controls with psychological symptoms but no ADHD. Results showed a 31% failure rate on the WMT. Those who failed the WMT showed clinical levels of self-reported ADHD symptoms and impaired neuropsychological performance. Neither self-report measures nor neuropsychological tests could distinguish ADHD from psychological controls, with the exception of self-reported current hyperactive/impulsive symptoms and Stroop interference. Results underscore the effect of noncredible performance on both self-report and cognitive measures in ADHD.

Reliability of Repeated Cognitive Assessment of Dementia Using a Brief Computerized Battery

Objective: The aim of this study was to evaluate the short-term stability and reliability of a brief computerized cognitive battery in established dementia types. Method: Patients were administered the computerized battery twice with administrations approximately 2 hours apart, with intervening conventional neuropsychological tests. Patients were classified clinically, via consensus conference, as healthy controls (n = 23), mild cognitive impairment (n = 20), Alzheimer’s disease (n = 52), dementia with Lewy Bodies ([DLB], n = 10), or frontotemporal dementia (n = 9). Results: Minimal practice effects were evident across Cog-State test administrations. Small magnitude improvements were seen across all groups on a working memory task, and healthy controls showed a mild practice effect on the accuracy of associative learning. Conclusions: In established dementia, administration of the CogState tasks appears sensitive to cognitive impairment in dementia. Repeat administration also provided acceptable stability and test-retest reliability with minimal practice effects at short test-retest intervals despite intervening cognitive challenges.

Validity of a Brief Computerized Cognitive Screening Test in Dementia

Background: While preliminary evidence supports the criterion validity of the CogState computerized brief battery in mild cognitive impairment (MCI) and Alzheimer disease (AD), definitive validation studies examining a wider range of dementia-related disorders relative to conventional neuropsychological techniques are necessary. Methods: Participants satisfying clinical consensus criteria for dementia (AD, n = 37; frontotemporal dementia, n = 7; and dementia with Lewy bodies, n = 5), MCI (n = 16), and the healthy controls (n = 22) were administered a battery of brief neuropsychological and select computerized (CogState) cognitive tests. The battery, administered through the University of Michigan Alzheimer’s Disease Research Center, included measures of processing speed, attention, working memory, and learning. Results: CogState and standard neuropsychological task scores were significantly lower for dementia participants than that of the nondementia groups (P < .05), with a single CogState test distinguishing control from MCI participants, but minimal differentiation existing between dementias using the CogState. Correlations were modest between conventional and computerized test scores, covering matching domains and mostly reflecting the multidimensional nature of cognitive paradigms. Conclusions: Results support the clinical validity of this brief computerized screening battery when used in established dementias, but not to differentiate between various dementias, and suggest that the select CogState battery’s effectiveness in identifying MCI from controls was not as strong as identifying specific dementias.

Amyloid Deposition and Cognition in Older Adults: The Effects of Premorbid Intellect

Although amyloid deposition remains a marker of the development of Alzheimers disease, results linking amyloid and cognition have been equivocal. Twenty-five community-dwelling non-demented older adults were examined with (18)F-flutemetamol, an amyloid imaging agent, and a cognitive battery, including an estimate of premorbid intellect and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). In the first model, (18)F-flutemetamol uptake significantly correlated with the Delayed Memory Index of the RBANS (r = -.51, p = .02) and premorbid intellect (r = .43, p = .03). In the second model, the relationship between (18)F-flutemetamol and cognition was notably stronger when controlling for premorbid intellect (e.g., three of the five RBANS Indexes and its Total score significantly correlated with (18)F-flutemetamol, rs = -.41 to -.58). Associations were found between amyloid-binding (18)F-flutemetamol and cognitive functioning in non-demented older adults. These associations were greatest with delayed memory and stronger when premorbid intellect was considered, suggesting that cognitive reserve partly compensates for the symptomatic expression of amyloid pathology in community-dwelling elderly.

Practical and Ethical Assessment Issues in Rural, Impoverished, and Managed Care Settings

The rising costs of new psychological tests, increased frequency of test revisions, and difficulty receiving authorization and reimbursement from managed care companies make it increasingly difficult for practitioners to provide the best standard of care to clients when conducting psychological and neuropsychological assessments. Practitioners, especially those in low-income and rural areas, may struggle with handling these practical realities while maintaining ethical standards in conducting psychological assessment. Suggestions for how to manage practical challenges faced by practitioners who provide psychological assessments, such as selecting tests when authorization or reimbursement by a third-party payer is restricted or denied, purchasing psychological tests on a budget, and providing assessments with a limited number of qualified staff are discussed. The authors also provide recommendations for the future prevention of these challenges through work with test developers, test publishing corporations, third-party payers, political action groups, and the psychology profession itself.

Short-term practice effects in mild cognitive impairment: Evaluating different methods of change

ABSTRACT Practice effects are improvements on cognitive tests as a result of repeated exposure to testing material. However, variability exists in the literature about whether patients with amnestic mild cognitive impairment (MCI) display practice effects, which may be partially due to the methods used to calculate these changes on repeated tests. The purpose of the current study was to examine multiple methods of assessing short-term practice effects in 58 older adults with MCI. The cognitive battery, which included tests of memory (Hopkins Verbal Learning Test–Revised and Brief Visuospatial Memory Test–Revised) and processing speed (Symbol Digit Modalities Test and Trail Making Test Parts A and B), was administered twice across one week. Dependent t tests showed statistically significant improvement on memory scores (ps < .01, ds = 0.8–1.3), but not on processing speed scores. Despite this, the sample showed no clinically meaningful improvement on any cognitive scores using three different reliable change indices. Regression-based change scores did identify relatively large groups of participants who showed smaller than expected practice effects, which may indicate that this method is more sensitive in identifying individuals who may portend a declining trajectory. Practice effects remain a complex construct, worthy of continued investigation in diverse clinical conditions.

Clinical utility of auditory memory testing in a heart failure population.

Background:The self-care regimen necessary in heart failure (HF) is notably complex. A complication to integrating new knowledge and behaviors is that impaired cognition has been frequently reported in patients with HF, which significantly impacts patients’ health, admission and mortality rates, and instrumental activities of daily living. Objective:The identification of reliable cognitive screening tools to assess potential difficulties in performing self-care for cardiac populations is essential. As such, the current purposes were to evaluate the validity and stability of the International Shopping List (ISL) auditory learning subtest from the computerized CogState battery as a screening tool in HF populations, determine the ISL’s ability to predict functional declines, and evaluate the task’s sensitivity in myocardial infarction. Methods:Forty patients with chronic HF were enrolled in a longitudinal study evaluating the impact of a cognitive training intervention. Baseline neuropsychological and behavioral measurements before treatment were used in the current study, including measures of auditory memory, orientation, verbal fluency, processing speed, and activities of daily living, and a subset of patients (n = 17) received repeat testing at 8 weeks on some tasks. Analyses also were performed with patients organized based on myocardial infarction status. Results:The current study indicated that the ISL performed comparably with an established measure of auditory memory (Hopkins Verbal Learning Test-Revised; r = 0.70, P < .001), displayed adequate coefficients of stability (r = 0.53–0.68), and successfully predicted declines over time in daily functioning (&bgr; = .47, P < .001) in our HF sample. Conclusions:The computerized CogState auditory memory subtest, the ISL, seems to be a beneficial tool in evaluating cognitive change in HF patients. Particularly given its cross-cultural sensitivity and ease of administration and scoring, this task may provide assistance to quickly and reliably monitor memory functioning in these vulnerable patients and gauge their potential for self-care behaviors.

Amyloid positivity using [18F]Flutemetamol-PET and cognitive deficits in nondemented community-dwelling older adults

Little research exists examining the relationship between beta-amyloid neuritic plaque density via [18F]flutemetamol binding and cognition; consequently, the purpose of the current study was to compare cognitive performances among individuals having either increased amyloid deposition (Flute+) or minimal amyloid deposition (Flute−). Twenty-seven nondemented community-dwelling adults over the age of 65 underwent [18F]flutemetamol amyloid-positron emission tomography imaging, along with cognitive testing using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and select behavioral measures. Analysis of variance was used to identify the differences among the cognitive and behavioral measures between Flute+/Flute− groups. Flute+ participants performed significantly worse than Flute− participants on RBANS indexes of immediate memory, language, delayed memory, and total scale score, but no significant group differences in the endorsed level of depression or subjective report of cognitive difficulties were observed. Although these results are preliminary, [18F]flutemetamol accurately tracks cognition in a nondemented elderly sample, which may allow for better prediction of cognitive decline in late life.

Predicting Premorbid Scores on the Repeatable Battery for the Assessment of Neuropsychological Status and their Validation in an Elderly Sample

OBJECTIVE Assessing cognitive change during a single visit requires the comparison of estimated premorbid abilities and current neuropsychological functioning. Although premorbid intellect has been widely examined, premorbid expectations for other cognitive abilities have received less attention. The current study sought to develop and validate premorbid estimates for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). METHOD Using demographic variables and an estimate of premorbid intellect, premorbid performance on the RBANS was predicted in a sample of 143 community-dwelling, cognitively intact older adults. RESULTS On all six Indexes of the RBANS, premorbid intellect was the best predictor of current cognitive functioning, with gender adding to one of the prediction models (R2 = 0.04-0.16, ps < .02). These prediction formulae were then applied to a sample of 122 individuals with amnestic Mild Cognitive Impairment to look for discrepancies between premorbid and current RBANS scores. Despite minimal differences between premorbid and current RBANS scores in the intact sample, large, and statistically significant differences were observed in the impaired sample, especially on the Immediate Memory Index (discrepancy = -29.00, p < .001), Delayed Memory Index (discrepancy = -32.28, p < .001), and Total Scale score (discrepancy = -25.58, p < .001). CONCLUSION Although validation in larger samples is needed, the current estimates of premorbid RBANS abilities may aid clinicians in determining change across time.

Validity of a verbal incidental learning measure from the WAIS-IV in older adults

ABSTRACT Incidental memory may reflect a form of learning in everyday life, although it is not consistently evaluated during standard neuropsychological evaluations. Further validation of a recently created measure of verbal Incidental Learning (IL) from the Wechsler Adult Intelligence Scale-IV is necessary to understand the utility of such a measure in clinical settings. Sixty-eight adults aged 50 to 89 were recruited from a Cognitive Disorders Clinic while receiving a standard neuropsychological assessment, along with two additional measures of IL. IL-Total Score was significantly correlated with immediate and delayed memory trials from standard neuropsychological tests (rs = .43 to .73, ps < .001, ds = 0.94–2.14), with worse IL performance being associated with lower memory abilities. Participants with probable Alzheimer’s disease performed worse on the IL-Total Score than participants with Mild Cognitive Impairment, t(39.997) = 5.46, p < .001, d = 1.13. Given the strong relationships between this IL task and traditional memory measures in our sample, and the discrimination of IL-Total Score performance among diagnostic groups despite its short administration time, this IL task may play a role as a measure of memory in brief cognitive evaluations.