Commentary on cognitive impairment with toxigenic fungal exposure.

Recently, Gordon et al. (2004) published an article entitled "Cognitive Impairment Associated with Toxigenic Fungal Exposure: A Replication and Extension of Previous Findings." That article claims that neurocognitive deficits are pervasive in persons self-diagnosed with "toxic" mold exposure relative to historical norms. Further, Gordon et al. argue exposure to household molds causes brain damage similar to closed head injury. Examination of their methodology reveals unfounded and unreliable conclusions due to deviations from sound epidemiological principles, bias in participant selection, misleading data analysis, and implausible causal reasoning. The purpose of this critique is to outline the specific design and reasoning flaws that, if not addressed, would lead to unwarranted conclusions regarding the effects of mold exposure.

The Fake Bad Scale and MMPI-2 F-family in detection of implausible psychological trauma claims.

We tested the validity of the Lees-Haley Fake Bad Scale (FBS) and the family of MMPI-2 F scales (F-family; F, F(p), and F-K scales) in predicting improbable psychological trauma claims in an applied setting. Litigants reporting implausible symptoms long after minor scares and nonlitigants clinically referred following severe stressors completed the MMPI-2. Both groups were naturally matched on social class. The FBS demonstrated sensitivity, specificity, and positive predictive power in the detection of atypical problems but the F-family showed poor utility. FBS cutting scores derived from logistic regression were applied to a third group made up of litigants with histories of undeniably severe traumas. A substantial number of this third group scored above cutoffs for exaggeration, but this finding is ambiguous. Reasons for the F-family's insensitivity to real-world exaggeration may include using student simulators for validation and content reflective of psychotic simulation. The superiority of the FBS in applied forensic settings could derive from its development in actual litigants and content reflective of nonpsychotic exaggerations. The FBS appears acceptable for use in applied forensic settings where persons seek compensation for nonpsychotic syndromes.

Methodological problems in the neuropsychological assessment of effects of exposure to welding fumes and manganese.

Recently, Kaiser (2003) raised concerns over the increase in brain damage claims reportedly due to exposure to welding fumes. In the present article, we discuss methodological problems in conducting neuropsychological research on the effects of welding exposure, using a recent paper by Bowler et al. (2003) as an example to illustrate problems common in the neurotoxicity literature. Our analysis highlights difficulties in conducting such quasi-experimental investigations, including subject selection bias, litigation effects on symptom report and neuropsychological test performance, response bias, and scientifically inadequate casual reasoning.

Premorbid clues? Preinjury scholastic performance and present neuropsychological functioning in late postconcussion syndrome.

Neuropsychologists rely on demographic variables to form assumptions about premorbid status, and most use years of education as the main variable. School records are a more objective basis for such estimation, particularly in litigated cases. In the present study, final cumulative grade point average (GPA) was regressed on to Halstead-Reitan Battery (HRB), IQ and other neuropsychological test scores in 60 nonmalingering postconcussive litigants and 17 litigants with moderate-severe closed head injury. Results indicated significant correlations between GPA, HRB core tests, commonly used neuropsychological measures, and intelligence. A regression formula indicated litigants with poor grade point average were likely to perform in the impaired range. The present findings suggest the quality of premorbid academic performance also provides an important context in which to view present neuropsychological performance. Marginal premorbid achievement may be a risk factor for late developing postconcussion syndrome and litigation.

The fake bad scale in atypical and severe closed head injury litigants.

The correlational and diagnostic properties of Lees-Haley's MMPI-2 Fake Bad Scale (FBS) were examined in litigating atypical minor, litigating moderate-severe, and non-litigating moderate-severe head injury samples. Overall, the FBS was sensitive to both litigation status and nonconforming versus conforming symptom courses. The FBS appeared superior to the MMPI-2 F and F-K scales in differentiating atypical from real brain-injury outcomes. High FBS scorers also had higher scores on somatic complaining (Hs, Hy) and to a lesser degree with psychotic complaints (F, Pa, Sc). FBS showed significant associations with various neuropsychological symptom validity measures. FBS appears to capture a hybrid of infrequent symptom reporting styles with an emphasis on unauthentic physical complaints. However, FBS also correlated with documented abnormal neurological signs within a litigating moderate-severe brain-injury group. Its use as a symptom infrequency measure may have to be modified in more severe injury litigants, as some FBS items may reflect true long-term outcome in severe cerebral dysfunction.

Neuropsychological and psychosocial correlates of adult arithmetic deficiency.

The purpose of this study was to examine adult correlates of rule-derived arithmetic deficiency. The authors collected neuropsychological, handedness, gender, and psychosocial data of adults with stringently defined arithmetic deficiency (AD; N = 45), reading deficiency (N = 45), and dual deficiency (N = 45). The authors did not match groups on IQ score and did not restrict analyses to right-handed men. The results indicated that AD in adults is associated with nonverbal reasoning and constructional problems. Otherwise, there was no association between AD and dysphoric complaints as defined by Minnesota Multiphasic Personality Inventory elevations. The authors also found overall intelligence was lower in adults with AD, and gender distribution differed markedly from the reading and dual deficient groups. Potential gender bias in remediation referral patterns was identified.

Actual versus self-reported scholastic achievement of litigating postconcussion and severe closed head injury claimants.

Psychologists typically rely on patients' self-report of premorbid status in litigated settings. The authors examined the fidelity between self-reported and actual scholastic performance in litigating head injury claimants. The data indicated late postconcussion syndrome (LPCS) and severe closed head injury litigants retrospectively inflated scholastic performance to a greater degree than nonlitigating control groups. The LPCS group showed the highest magnitude of grade inflation, but discrepancy scores did not significantly correlate with a battery of malingering measures or with objective cerebral dysfunction. These findings support previous studies, which showed self-report is not a reliable basis for estimation of preinjury cognitive status. Retrospective inflation may represent a response shift bias shaped by an adversarial context rather than a form of malingering.