Glenn J. Larrabee

American Academy of Clinical Neuropsychology Consensus Conference Statement on the Neuropsychological Assessment of Effort, Response Bias, and Malingering

During the past two decades clinical and research efforts have led to increasingly sophisticated and effective methods and instruments designed to detect exaggeration or fabrication of neuropsychological dysfunction, as well as somatic and psychological symptom complaints. A vast literature based on relevant research has emerged and substantial portions of professional meetings attended by clinical neuropsychologists have addressed topics related to malingering (Sweet, King, Malina, Bergman, & Simmons, 2002). Yet, despite these extensive activities, understanding the need for methods of detecting problematic effort and response bias and addressing the presence or absence of malingering has proven challenging for practitioners. A consensus conference, comprised of national and international experts in clinical neuropsychology, was held at the 2008 Annual Meeting of the American Academy of Clinical Neuropsychology (AACN) for the purposes of refinement of critical issues in this area. This consensus statement documents the current state of knowledge and recommendations of expert clinical neuropsychologists and is intended to assist clinicians and researchers with regard to the neuropsychological assessment of effort, response bias, and malingering.

A review of mild head trauma. part I: Meta-analytic review of neuropsychological studies

We conducted a meta-analytic review of neuropsychological studies of mild head trauma (MHT). Studies were included if they met these criteria: patients studied at least 3 months after MHT; patients selected because of a history of MHT rather than because they were symptomatic; and attrition rate of less than 50% for longitudinal studies. Studies of children were not considered. We found a total of 8 published papers with 11 samples that met these criteria. Using the g statistics, the overall effect size of 0.07 was nonsignificant, but the d statistic yielded an effect size of 0.12, p < .03. Measurers of attention had the largest effect, g = 0.17. p < .02 and d = 0.20, p < .006. Severity of injury accounted for far more variance than did specific neuropsychological domain, however. The small effect size suggests that the maximum prevalence of persistent neuropsychological deficit is likely to be small and neuropsychological assessment is likely to have positive predictive value of less than 50%. Consequently, clinicians will more likely be correct when not diagnosing brain injury than when diagnosing a brain injury in cases with chronic disability after MHT.

Detection of Malingering Using Atypical Performance Patterns on Standard Neuropsychological Tests

Cut-off scores defining clinically atypical patterns of performance were identified for five standard neuropsychological and psychological tests: Benton Visual Form Discrimination (VFD), Fingertapping (FT), WAIS-R Reliable Digit Span (RDS), Wisconsin Card Sorting Failure-to-Maintain Set (FMS), and the Lees-Haley Fake Bad Scale (FBS) from the MMPI-2. All possible pair-wise combinations of scores beyond cut-off (e.g., for VFD and FT; for RDS and FBS), correctly identified 21 of 24 subjects (87.5%) meeting criteria for definite malingered neurocognitive dysfunction, and 24 of 27 (88.9%) subjects with moderate to severe closed head injury. On cross-validation, 15 of 17 subjects (88.2%) meeting criteria for probable malingered neurocognitive dysfunction were correctly identified, with 13 of 13 nonlitigating neurologic patients, and 14 of 14 nonlitigating psychiatric patients correctly classified as having motivationally-preserved performance. Combining the derivation and cross-validation samples yielded a sensitivity of 87.8%, specificity of 94.4%, and combined hit rate of 91.6%.

Assessment of memory complaint in age-associated memory impairment: the MAC-Q.

Few brief self-report memory questionnaires are available, and non has been well validated. We designed a brief questionnaire, the MAC-Q, to assess age-related memory decline. Validity and reliability of the MAC-Q were assessed in 232 subjects meeting diagnostic criteria for age-associated memory impairment (AAMI). Concurrent validity of the MAC-Q was supported by a significant correlation (r = .41, p < .001) with a lengthy, well-validated memory questionnaire. Multiple regression analysis indicated that memory test scores were significant predictors of MAC-Q scores. MAC-Q scores were not predicted by Hamilton Depression Scale scores, suggesting that memory complaint in AAMI is not related to affective status. Internal consistency and test-retest reliability of the MAC-Q were satisfactory. Our data support the validity and reliability of the MAC-Q, a new brief memory questionnaire. The MAC-Q is of particular relevance to the assessment of AAMI, but should also prove useful in any clinical or research setting requiring a brief index of memory complaint.

A Meta-Analysis of Neuropsychological Outcome After Mild Traumatic Brain Injury: Re-analyses and Reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009)

The meta-analytic findings of Binder et al. (1997) and Frencham et al. (2005) showed that the neuropsychological effect of mild traumatic brain injury (mTBI) was negligible in adults by 3 months post injury. Pertab et al. (2009) reported that verbal paired associates, coding tasks, and digit span yielded significant differences between mTBI and control groups. We re-analyzed data from the 25 studies used in the prior meta-analyses, correcting statistical and methodological limitations of previous efforts, and analyzed the chronicity data by discrete epochs. Three months post injury the effect size of −0.07 was not statistically different from zero and similar to that which has been found in several other meta-analyses (Belanger et al., 2005; Schretlen & Shapiro, 2003). The effect size 7 days post injury was −0.39. The effect of mTBI immediately post injury was largest on Verbal and Visual Memory domains. However, 3 months post injury all domains improved to show non-significant effect sizes. These findings indicate that mTBI has an initial small effect on neuropsychological functioning that dissipates quickly. The evidence of recovery in the present meta-analysis is consistent with previous conclusions of both Binder et al. and Frencham et al. Our findings may not apply to people with a history of multiple concussions or complicated mTBIs.

Estimated Prevalence of Age-Associated Memory Impairment Derived From Standardized Tests of Memory Function

Recent research on the prevalence of age-associated memory impairment (AAMI) has reflected considerable variability, with estimates ranging from 35% to 98%. This variability is attributed to (a) failure to employ the complete diagnostic criteria for AAMI and (b) failure to consider age as a variable in estimating prevalence. Analysis of published normative data on both standard clinical memory tests and computer-simulated everyday memory tests shows a clear increase in the percentage of persons meeting the AAMI memory performance criterion as a function of age. These data are offered as an upper-bound estimate of the prevalence of AAMI, by age decade.

Factors Attenuating the Validity of the Geriatric Depression Scale in a Dementia Population

The validity of the Geriatric Depression Scale (GDS) in cognitively impaired patients has been questioned. We investigated possible factors (memory loss, dementia severity, unawareness of illness) attenuating the validity of the GDS in patients with dementia.

Exaggerated MMPI-2 symptom report in personal injury litigants with malingered neurocognitive deficit

Traditional MMPI-2 validity scales, the Lees-Haley Fake Bad Scale (FBS), and the Arbisi and Ben Porath Infrequency Psychopathology Scale (F(p)) were evaluated in 33 personal injury litigants who had failed forced-choice symptom validity testing and other measures of effort in patterns consistent with the Slick, Sherman, and Iverson (1999) criteria for definite and probable malingered neurocognitive deficit (MND). The FBS was more sensitive to symptom exaggeration than F, Fb, and F(p). The definite and probable MND litigants also produced mean elevations on MMPI-2 scales 1, 3 and 7 that were significantly higher than those produced by various clinical groups including non-litigating severe closed head injury, multiple sclerosis, spinal cord injury, chronic pain, and depression. These data suggest that MMPI-2 profiles characteristic of malingered injury differ from those associated with malingered psychopathology.

Construct validity of various verbal and visual memory tests

Factor analysis was conducted on attention, information processing, verbal and visual memory scores of 112 patients. Factor structure did not vary as a function of age. The Expanded Paired Associates Test, Verbal Selective Reminding Test, Continuous Recognition Memory Test, and Continuous Visual Memory Test defined a general memory factor. The PASAT, WMS Mental Control, and WAIS-R Digit Span defined an attention/information processing factor. Immediate Visual Reproduction (VR) loaded primarily on visual/nonverbal intelligence, whereas delayed VR loaded primarily with the memory factor. The Trail Making Test, Part B was more closely associated with visual/nonverbal intelligence than with attention/information processing. Serial Digit Learning was more closely associated with attention/information processing than with general memory.

Effort Indicators within the California Verbal Learning Test-II (CVLT-II)

This study determined whether performance patterns on the California Verbal Learning Test-II (CVLT-II) could differentiate participants with traumatic brain injury (TBI) showing adequate effort from those with mild TBI exhibiting poor effort using a case-control design. The TBI group consisted of 124 persons with moderate to severe traumatic brain injury (TBI). The poor effort group consisted of 77 persons with mild head injury who were involved in litigation (LG) and failed at least one stand-alone symptom validity measure (SVT) and also either a second SVT or an effort indicator embedded within a standard clinical test. A total of 18 CVLT-II variables were investigated using Bayesian model averaging (BMA) for logistic regression to determine which variables best differentiated the groups. The CVLT-II variables having the most support were Long-Delay Free Recall, Total Recognition Discriminability (d′), and Total Recall Discriminability.