Base rate of a WMS-R malingering index in a sample of non-compensation-seeking men infected with HIV-1.

HIV-1 infected persons who are pursuing disability benefits are increasingly seeking neuropsychological assessment for purposes of corroborating functional impairment. Thus, research on the utility of measures of symptom validity among these patients is needed. Recently, Mittenberg, Azrin, Millsaps, and Heilbronner (1993) proposed a malingering index score for the WechslerMemoryScale-Revised that is derived by subtracting the Attention/Concentration Index (ACI) score from the General Memory Index Score (GMI). This study is a cross-validation of the specificity of the GMI-ACI Malingering Index in a sample of 55 non-compensation-seeking HIV-positive (HIV+) patients. An overall false-positive rate of 7% was observed for the GMI-ACI Malingering Index. However, further analyses showed that GMI-ACI Malingering Index scores were correlated with GMI scores such that false-positive errors were substantially higher (18%) among patients who obtained above-average GMI scores. These findings suggest a cautious approach to application of the GMI-ACI Malingering Index, particularly among patients who obtain above-average GMI scores.

California Verbal Learning Test indicators of suboptimal performance in a sample of head-injury litigants.

Cutoff scores suggested by Millis, Putnam, Adams, and Ricker (1995) for detecting suboptimal performance on indices from the California Verbal Learning Test (CVLT) were evaluated using data from 193 compensation-seeking participants. All participants claimed to have suffered a blow to the head in an accident causing subsequent deterioration in cognitive function. The participants were divided into those with negligible or possible mild brain injuries and those with clear evidence of moderate to severe brain injuries. In addition to the CVLT, all participants were administered the Computerized Assessment of Response Bias (CARB), a two-alternative forced choice test of recognition memory that is used to detect feigned cognitive impairment. For all CVLT indices, the distributions of outcome (valid vs. suboptimal performance) was unrelated to age and brain injury severity, and only weakly associated with education. However, a significantly higher proportion of males than females obtained scores in the suboptimal performance range. The CVLT indices were not fully redundant with each other with respect to binary participant classifications; substantial disagreement between pairwise classifications was found among those participants who obtained at least one score in the suboptimal performance range. CVLT index classifications were also found to be non-redundant with classifications based on CARB scores. The CVLT may thus add useful data over and above that obtained from symptom validity testing. However, the data suggest that the use of the strategy where any one or more below-cutoff CVLT scores are considered a positive indicator of suboptimal performance may be associated with a higher than acceptable false-positive error rate.

Effect of depression on neuropsychological functioning in head injury: measurable but minimal.

The goals of the study were to determine how neuropsychological functioning is related to depressive status in persons with head injury, and to quantify this relationship from a clinically relevant standpoint. Participants were 175 adults involved in litigation, referred for evaluation of suspected head injury. Depression status was measured using the Depression Content (Dep) scale of the MMPI-2. Depression status was related to measures of visual attention and psychomotor skills, but not to other neuropsychological domains such as verbal ability, visual-spatial reasoning, or encoding/organization. However, differences between low Dep and high Dep groups were minimal from a clinical standpoint. Depression appeared to contribute to an increased risk of impaired neuropsychological performance across domains, but only in persons not severely compromised by neuropsychological deficits. Overall, the results indicated a small effect of depression on neuropsychological functioning that is likely only detectable in persons whose neuropsychological compromise is relatively minimal.

Evaluation of a WMS-R malingering index in a non-litigating clinical sample.

The purpose of this study was to examine the prevalence of a Wechsler Memory Scale-Revised "malingering index" in a large sample of non-litigating individuals from an inpatient substance abuse program. Past research has demonstrated that experimental-malingerers often obtain substantially lower scores on the Attention/Concentration Index than on the General Memory Index. In the present study, only a small percentage of patients showed large General Memory - Attention/Concentration difference scores. These results provide further support for the validity of this difference score as a marker for non-optimal effort.

Clinical normative data for the WCST-64 following uncomplicated mild head injury.

Clinical norms for the 64-item Wisconsin Card Sorting Test (WCST-64) are presented. The norms were derived from 303 persons presenting for emergency services who met criteria for uncomplicated mild head injury. Most data were obtained within 2 days of injury, and the remaining data were obtained within 10 days of injury. The norms may be used to help determine whether or not a person's scores on the WCST-64 are typical of those seen shortly after sustaining an uncomplicated mild head injury.

Using intraindividual variability to detect malingering in cognitive performance.

The utility of measures for detecting malingering was evaluated using a simulation design in which half the participants were encouraged to do their best and half were asked to feign head injury. Particular attention was focused on the utility of repeated assessment (intraindividual variability) in discriminating the groups. Participants were tested on three occasions on measures commonly used to detect malingering including a specific symptom validity test (SVT). The results indicated that multiple measures of malingering obtained in single assessment (occasion one) discriminated the groups effectively. In addition, however, intraindividual variability in performance, particularly of indicators from the SVT, provided unique information beyond level of performance. The results suggest that response inconsistency across testing sessions may be a clinically useful measure for the detection of malingering.

Diagnostic criteria for malingered neurocognitive dysfunction: proposed standards for clinical practice and research.

Over the past 10 years, widespread and concerted research efforts have led to increasingly sophisticated and efficient methods and instruments for detecting exaggeration or fabrication of cognitive dysfunction. Despite these psychometric advances, the process of diagnosing malingering remains difficult and largely idiosyncratic. This article presents a proposed set of diagnostic criteria that define psychometric, behavioral, and collateral data indicative of possible, probable, and definite malingering of cognitive dysfunction, for use in clinical practice and for defining populations for clinical research. Relevant literature is reviewed, and limitations and benefits of the proposed criteria are discussed.

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

Error scores and response times from a computer-administered, forced-choice recognition test of symptom validity were evaluated for efficiency in detecting feigned memory deficits. Participants included controls (n = 95), experimental malingerers (n = 43), compensation-seeking patients (n = 206), and patients not seeking financial compensation (n = 32). Adopting a three-level cut-score system that classified participant performance as malingered, questionable, or valid greatly improved sensitivity with relatively little impact on specificity. For error scores, convergent validity was found to be adequate and divergent validity was found to be excellent. Although response times showed promise for assisting in the detection of feigned impairment, divergent and convergent validity were weaker, suggesting somewhat less utility than error scores.

Neuropsychological assessment in public psychiatric hospitals: the changing state of the practice-1979 to 1989.

A ten-year follow-up survey of clinicians in publicly funded adult psychiatric hospitals throughout the United States was conducted to assess changes and trends in the practice of clinical neuropsychology. An 85% response rate was achieved. The survey produced data on the type and number of neuropsychological testing instruments in use, the type of training received by clinicians performing neuropsychological assessments, the psychiatric patient load and proportion of referrals which involve neuropsychological questions, the proportion of institutions employing psychologists with primarily neuropsychological duties, and the perceived efficacy of neuropsychological assessment techniques for discriminating functional from organic disorders. The findings indicate an increase in the level and variety of training as well as in the number of neuropsychological specialists in the field. However, levels of staffing appear to remain below service needs. Additional findings indicate the continued popularity of a small number of neuropsychological test batteries, a marked increase in the variety of testing instruments in use, and a general sense of trust in the efficacy of neuropsychological assessment techniques. The implications of these findings for the future of applied human neuropsychology are discussed.