Development of the MMPI-2 cognitive complaints scale as an embedded measure of symptom validity.

OBJECTIVE: To empirically-derive a new MMPI-2 sub-scale, the 13-item Cognitive Complaints Scale (CCS), as an embedded measure of symptom validity. This study hypothesized that mild traumatic brain injured subjects with financial incentives who failed performance validity tests (PVTs) would score significantly higher on the CCS compared to mild traumatic brain injured subjects with financial incentives who passed PVTs. Mild traumatic brain injured controls with no financial incentives were predicted to score lowest on the CCS. RESEARCH DESIGN: A known groups design was utilized as this design allows for the accurate classification of criterion groups. METHODS: One hundred and fifty mild head-injured adults were assigned to one of three groups: the Failed Performance Validity (FPV) group, the Passed Performance Validity (PPV) group or a control group. RESULTS: An ANOVA revealed that the FPV group scored significantly higher on the CCS compared to the PPV group. Controls with no financial incentives scored lowest. A CCS cut-score of ≥12 discriminated between the FPV and PPV groups at a high level of specificity (94%). CONCLUSIONS: A dissociation between 'performance validity' and 'symptom validity' supports recommendations for the differential application of these descriptive terms. The CCS may be helpful to assess credibility of clinical presentation in situations where PVTs are absent.

False positive diagnosis of malingering due to the use of multiple effort tests.

OBJECTIVE: Effort indicators are used to determine if neuropsychological test results are valid measures of a patient's cognitive abilities. The use of multiple effort measures is often advocated, but the false positive rate for multiple indicators depends on the number of measures used and the correlation among indicators. This study presents a meta-analysis of correlations among effort measures. False positive rates for multiple correlated indicators are then estimated using Monte Carlo simulations. METHODS: a literature search of published studies identified 22 independent samples in which 407 correlations among 31 effort measures were available in 3564 participants with normal effort. Participants were patients with neurological or psychiatric disorders and healthy volunteers. RESULTS: Meta-analysis showed a mean correlation among effort indicators of 0.31. Monte Carlo simulation based on a 15% false positive rate for individual indicators showed that, when 10 effort indicators are used together, 38% of patients with valid performance will be incorrectly identified as malingering if two failures is the diagnostic standard. Failure on five of 10 measures is required for a false positive rate of 10% or less. If five effort indicators are interpreted, a false positive rate of 19% results when two test failures are assumed to characterize poor effort and failure on three measures is required to maintain 90% specificity. CONCLUSIONS: False positive rates for effort tests increase significantly as the number of indicators that are administered is increased.

Noncredible performance in individuals with external incentives: empirical derivation and cross-validation of the Psychosocial Distress Scale (PDS).

Using a known groups design, a new Minnesota Multiphasic Personality Inventory (MMPI-2) subscale, the 20-item Psychosocial Distress Scale (PDS), was empirically derived and cross-validated. The PDS demonstrated good classification accuracy between subjects under external incentive vs. no incentive conditions. In the initial calibration sample (N = 84) a cut score of ≥10 on the PDS was associated with good classification accuracy (85.7%), high specificity (90.0%), and adequate sensitivity (81.8%). Under cross-validation conditions (N = 83) a cut score of ≥10 on the PDS was also associated with nearly identical classification accuracy (86.5%), specificity (91.89%), and sensitivity (82.61%). A cut score of ≥12 was associated with 100% positive predictive power; that is, no false-positive errors in both the initial calibration sample and the subsequent cross-validation sample. The current study suggests that in addition to noncredible cognitive performance, civil litigants and disability claimants may overreport psychosocial complaints that can be identified and that the scale may generalize to other settings and patient groups.

Apparently abnormal Wechsler Memory Scale index score patterns in the normal population.

Interpretation of the Wechsler Memory Scale-Fourth Edition may involve examination of multiple memory index score contrasts and similar comparisons with Wechsler Adult Intelligence Scale-Fourth Edition ability indexes. Standardization sample data suggest that 15-point differences between any specific pair of index scores are relatively uncommon in normal individuals, but these base rates refer to a comparison between a single pair of indexes rather than multiple simultaneous comparisons among indexes. This study provides normative data for the occurrence of multiple index score differences calculated by using Monte Carlo simulations and validated against standardization data. Differences of 15 points between any two memory indexes or between memory and ability indexes occurred in 60% and 48% of the normative sample, respectively. Wechsler index score discrepancies are normally common and therefore not clinically meaningful when numerous such comparisons are made. Explicit prior interpretive hypotheses are necessary to reduce the number of index comparisons and associated false-positive conclusions. Monte Carlo simulation accurately predicts these false-positive rates.

Selection criteria for internships in clinical neuropsychology.

Criteria used in the evaluation and selection of applicants for clinical neuropsychology internships were identified by a survey of programs that met guidelines for specialty training. The number of internships that offer training with specialization in clinical neuropsychology has more than doubled during the past 10 years. Supervising neuropsychologists from 75 programs replied to the survey, yielding a 72.8% response rate. Clinical experience in neuropsychological assessment, specialization in clinical neuropsychology during graduate education, personal interview, and letters of recommendation were reported to be the most salient selection criteria. Practica that provide experience with flexible or functional systems assessment approaches at university-affiliated or VA (U.S. Department of Veterans Affairs) medical centers and doctoral curricula that follow International Neuropsychological Society/Division 40 course guidelines, with teaching and supervision provided by neuropsychologists, were preferred prerequisites to internship. These results are consistent with selection criteria reported over a decade ago and indicate continued endorsement of the vertically integrated model of education and training outlined by the Houston Conference on Specialty Education and Training in Clinical Neuropsychology.

Rates of apparently abnormal MMPI-2 profiles in the normal population.

MMPI-2 standardization data were re-sampled using Monte Carlo simulations to estimate the base rate of apparently abnormal scores expected by chance in the normal population when multiple scales are interpreted. 36.8% of normal adults are likely to obtain a score that would otherwise be considered clinically significant at 65T on one or more of the 10 Clinical scales. The normal incidence of at least one apparently abnormal score was 38.3% on the Content and 55.1% on the Supplementary scales. When the Clinical, Supplementary, and Content scales and subscales are interpreted together, at least three seemingly meaningful scores will be found in 47.4% of perfectly normal individuals, and five or more scales that appear to be clinically significant can be expected in 30.1% of cases that are actually unremarkable. These results imply that the number of MMPI-2 scales that can be meaningfully interpreted in clinical practice is limited, and that high T-scores are necessary for an adequate level of confidence even when interpretation is appropriately limited to the Clinical scales.

Changes in intellectual functioning associated with normal aging.

Declines in IQ scores with advancing age have been observed in each successive revision of the Wechsler Intelligence Scales. This study examined age-related changes on the fourth edition of the Wechsler Adult Intelligence Scale and compared these to the effects seen on the 1955, 1981, and 1997 standardizations of the scales. The most pronounced declines were in measures of processing speed and nonverbal reasoning. Declines in nonverbal reasoning were similar on timed and un-timed measures. Verbal abilities remained relatively stable across the life span. General intelligence as assessed by the Full Scale IQ was reduced about 1 SD by age 75 when corrections for age were removed. Age-related declines have become less pronounced since 1955, particularly on measures of processing speed. This effect was essentially linear, unrelated to concurrent IQ increases in the general population, and paralleled a 9-year increase in life expectancy during this time period.

Comparison of the MMPI-2 restructured Demoralization Scale, Depression Scale, and Malingered Mood Disorder Scale in identifying non-credible symptom reporting in personal injury litigants and disability claimants.

A known groups design compared the ability of the 24-item MMPI-2 Restructured Clinical Demoralization Scale (RCd), the 57-item Depression Scale (Scale 2), and the 15-item Malingered Mood Disorder Scale (MMDS) to identify non-credible symptom response sets in 84 personal injury litigants and disability claimants compared to 77 non-litigating head-injured controls. All three scales showed large effect sizes (>0.80). Scale 2 was associated with the largest effect size (2.19), followed by the MMDS (1.65), and the RCd (0.85). Logistic regression analyses revealed that a cutscore of > or =28 on the 57-item Scale 2 was associated with high specificity (96.1%) and sensitivity (76.2%), while a cutscore of > or =16 on the 24-item RCd was less accurate (87% specificity and 50% sensitivity). Cutscores for the MMDS were not calculated as they were reported in a previous study. Results indicated that like the 15-item MMDS, the 57-item MMPI-2 Scale 2 may provide another empirically derived index with known error rates upon which examiners may rely to investigate hypotheses relative to exaggeration of illness-related behavior and impression management in forensic contexts involving PI litigants and disability claimants.

Empirical derivation of a new MMPI-2 scale for identifying probable malingering in personal injury litigants and disability claimants: the 15-item Malingered Mood Disorder Scale (MMDS).

A new 15-item MMPI-2 subscale, the Malingered Mood Disorder Scale (MMDS), was empirically derived from the original 32-item Malingered Depression Scale (MDS) of Steffan, Clopton, and Morgan (2003). The MMDS was superior to the original MDS in identification of symptom exaggeration in personal injury litigants and disability claimants compared to non-litigating head-injured controls. Logistic regression revealed that a cut score of > or = 7 on the MMDS produced good specificity (93.4%) with an associated sensitivity of 54.8%. An MMDS score of > or = 8 was associated with 100% positive predictive power, i.e., no false positive errors. These results suggest that the MMDS may be useful in identifying personal injury litigants and disability claimants who exaggerate emotional disturbance on the MMPI-2.

Comparison of the Lees-Haley Fake Bad Scale, Henry-Heilbronner Index, and restructured clinical scale 1 in identifying noncredible symptom reporting.

A known groups design investigated the comparative predictive validity of the 27-item MMPI-2 Restructured Scale 1 (RC1), the 43-item Lees-Haley Fake Bad Scale (FBS), and the 15-item Henry-Heilbronner Index (HHI) to identify noncredible symptom response sets in 63 personal injury litigants and disability claimants compared to 77 non-litigating head-injured controls. Logistic regression analyses revealed that the HHI and FBS were better predictors of group membership than the RC1. Results suggest that the FBS, HHI, and RC1 may be measuring different constructs. The HHI and FBS reflect an exaggeration of disability or illness-related behavior. Differences in scale construction are discussed. The RC1 may have greater relevance under external incentive conditions involving chronic pain patients, or clinical patients with no external incentive to exaggerate their symptom presentation.

The Henry-Heilbronner Index: a 15-item empirically derived MMPI-2 subscale for identifying probable malingering in personal injury litigants and disability claimants.

A new 15-item MMPI-2 subscale, the Henry-Heilbronner Index (HHI), representing a "pseudosomatic factor," was empirically derived from both the 43-item Lees-Haley Fake Bad Scale (FBS) and the 17-item Shaw and Matthews' Pseudoneurologic Scale (PNS). The HHI was superior to both the FBS and PNS in identification of symptom exaggeration in personal injury litigants and disability claimants compared to non-litigating head-injured controls. Logistic regression analyses revealed that a cutscore of > or = 8 on the HHI was associated with good specificity (89%) and sensitivity (80%). These results suggest that the HHI may be useful in identifying personal injury litigants and disability claimants who exaggerate, overreport, or malinger physical symptoms on the MMPI-2 related to their current health and/or litigation status.

Mood and anxiety disorders following pediatric traumatic brain injury: a prospective study.

Studies utilizing standardized instruments for assessing mood and/or anxiety disorders following pediatric traumatic brain injury have seldom been reported in the literature. Previous reports have largely focused on cognitive impairment, behavioral dysfunction, or adaptive functioning, and have typically relied on parental informants. In this study, children hospitalized for mild (N = 42) and moderate/severe (N = 19) brain injury were assessed 6-months postinjury using the Anxiety disorders Module A and the Mood disorders Module C of the Diagnostic Interview Schedule for Children - IV Revision (DISC-IV). The data collected for the brain injury groups were compared to an orthopedic control group (N = 35). The relationship between a new onset mood and/or anxiety disorder (NOD) and injury severity indices was examined. Sequential logistical regression was also utilized to examine the impact of a brain injury, demographic variables, preinjury psychiatric disturbance, development disorders, litigation status and postinjury environmental stress on emotional outcome. Results indicated a relationship between brain injury and NOD. Multivariate analysis demonstrated that postinjury level of stress and severity of brain injury were the most robust predictors of NOD, accounting for 23% of the variance in the model. These results support the premise that the development of a mood and/or anxiety disorder following pediatric head injury is mediated by multiple determinants. The findings suggest that early psychosocial assessment and interventions aimed at increasing a child's coping may attenuate the emotional consequences of pediatric brain injury.

Base rates of malingering and symptom exaggeration.

Base rates of probable malingering and symptom exaggeration are reported from a survey of the American Board of Clinical Neuropsychology membership. Estimates were based on 33,531 annual cases involved in personal injury, (n = 6,371). disability (n = 3,688), criminal (n = 1,341), or medical (n = 22,131) matters. Base rates did not differ among geographic regions or practice settings, but were related to the proportion of plaintiff versus defense referrals. Reported rates would be 2-4% higher if variance due to referral source was controlled. Twenty-nine percent of personal injury, 30% of disability, 19% of criminal, and 8% of medical cases involved probable malingering and symptom exaggeration. Thirty-nine percent of mild head injury, 35% of fibromyalgia/chronic fatigue, 31% of chronic pain, 27% of neurotoxic, and 22% of electrical injury claims resulted in diagnostic impressions of probable malingering. Diagnosis was supported by multiple sources of evidence, including severity (65% of cases) or pattern (64% of cases) of cognitive impairment that was inconsistent with the condition, scores below empirical cutoffs on forced choice tests (57% of cases), discrepancies among records, self-report, and observed behavior (56%), implausible self-reported symptoms in interview (46%), implausible changes in test scores across repeated examinations (45%), and validity scales on objective personality tests (38% of cases).