Neurobehavioral assessment in toxic injury evaluations.

Forensic neurobehavioral evaluations present special validity problems such that standard assumptions, procedures, histories, and fact-finding methods used in treatment settings may be inappropriate and misleading. This article discusses basic issues in assessing the quality and reasonableness of forensic toxic injury evaluations. Topics include selection of test instruments, history, functional assessment, threats to validity, voluntary manipulation of test results, chemophobia, limitations of the state of the art in neuropsychology and neurobehavioral assessment, base rates, and norms. Understanding the roles these topics play in toxic injury evaluations is essential to making informed judgments about the quality of forensic neurobehavioral evaluations.

Neuropsychological complaint base rates of 170 personal injury claimants.

Reports base rate data for 50 controls and 170 personal injury claimants' self-reported symptoms associated with neuropsychological impairment. These base rates were obtained from claimants with no history of brain injury or toxic exposure and no documented neuropsychological impairments. Personal injury claimants reported high rates of complaints generally recognized as being associated with neuropsychological impairment. For example, 93% reported anxiety or nervousness, 92% sleeping problems, 89% depression, 88% headaches, 79% fatigue, 78% concentration problems, 77% irritability, 65% impatience, 61% feeling disorganized, 59% confusion, 56% loss of efficiency with everyday tasks, 53% memory problems, 44% dizziness, 39% numbness, and 34% word finding problems. These results underscore the need for caution when relying, on self-reported symptoms as evidence of brain damage in patients involved in litigation.

The implications of limitations in hydrocarbon research for neuropsychological assessment.

As neuropsychologists are involved increasingly in the neuropsychological assessment of individuals reporting both acute and long-term exposure to hydrocarbons, the value of research for providing guidance also increases. Research findings inform neuropsychologists about likely neuropsychological deficits given certain intensity and duration of exposure and about neuropsychological tests most appropriate for detecting hydrocarbon-induced deficits. Although high-dose events are associated with neuropsychological deficits, methodological weaknesses in the existing research impede a consensus on the implications of low-dose exposures in humans. Three flaws inherent in research on low-dose hydrocarbon exposures and their implications for neuropsychological assessment of individuals are discussed: Selection bias in recruitment of research participants, biased recall of research participants, and between-study variation in neuropsychological tests and results. Because they undermine the reliability and validity of existing research, lack of awareness of these weaknesses may interfere with unbiased assessment of individual patients suspected of hydrocarbon-induced neuropsychological deficits. Examples from the social-cognitive psychological literature contribute to understanding how misleading research findings can lead experts to form expectancies that bias assessment of individuals.

Comment: Warning malingerers produces more sophisticated malingering.

Warning persons that attempts to malinger on neuropsychological testing will be detected is not an effective way of reducing malingering behavior. Rather, the literature on coaching consistently shows that malingerers who are warned of the presence of symptom validity assessment techniques are able to feign deficits in a less exaggerated and more believable fashion and therefore elude detection. Warning persons about the presence of these techniques reduces the validity and scientific quality of forensic evaluations. Rather than warning persons that they will be caught if they try to malinger, we recommend that persons be told to do their best and that forensic examiners encourage maximum effort, consistent with accepted testing practices and test manual instructions.

A comparison of complaints by mild brain injury claimants and other claimants describing subjective experiences immediately following their injury.

This study compares the rate of postconcussive (PCS) symptoms at the time of injury for mild traumatic brain injury (MTBI; N=24) claimants and claimants reporting other forms of injury (OI; N=66). On checklists surveying their complaints immediately after their injury, MTBI and OI claimants reported similar levels of many PCS complaints, e.g., dazed, confused, dizzy, disoriented, trouble concentrating, numbness or loss of sensation, and loss of memory for some of what happened. One in four of the OI samples reported partial loss of consciousness (LOC), and one-third reported loss of memory for some of what happened. About 67% of the MTBI sample reported being confused and 71% dazed, but so did many of the OI sample (52% dazed, 65% confused). The authors suggest that classical PCS complaints experienced immediately after an injury are so nonspecific that they have little diagnostic specificity.

Application of the Postconcussive Syndrome Questionnaire with medical and psychiatric outpatients.

The Postconcussive Syndrome Questionnaire (PCSQ; Lees-Haley, 1992) was previously found (Axelrod, Fox, Lees-Haley, Earnest, Dolezal-Wood, & Goldman, 1996) to produce four factors, named Psychological, Somatic, Cognitive, and Infrequency. These four factors of the questionnaire were evaluated across five groups of medical and psychiatric outpatients. The patients were from neurology, mental health, family practice, and internal medicine clinics as well as from a clinic that evaluated new patients to a health maintenance organization. Mental health patients had greater psychological symptoms and fewer health concerns than the other groups. Neurology patients differed from the other groups by having greater Infrequency symptoms. Patients who were referred for their screening evaluation or were seen by internal medicine had fewer overall symptoms than the other three patient groups. The data from this study provide support for the use of the PCSQ as a multifactorial self-report measure of symptom presentation.

Ego strength denial on the MMPI-2 as a clue to simulation of personal injury in vocational neuropsychological and emotional distress evaluations.

Ego Strength (Es) scores on the MMPI-2 were compared for malingering and nonmalingering samples of personal injury claimants. These data suggest that the Es scale has utility in differentiating these two samples. A cut-off score of Es less than 31 is suggested for identifying personal injury malingerers in nonpsychotic outpatient population who are not obviously grossly disabled. Cross-validation is recommended.

Vocational neuropsychological requirements of U.S. occupations.

Aptitude levels required to perform occupations listed in the U.S. Department of Labor Dictionary of Occupational Titles are indicated. Numbers and percentages of jobs requiring each level of each aptitude are presented in a tabular format. These data can be useful in assisting vocational neuropsychologists in evaluating brain-injury disability cases.

Effect of information about odor on causal ascriptions for illness.

The effect of information about detection of an odor on causal ascriptions for illness was investigated. In four different scenarios perceptions regarding the cause of a hypothetical symptomatic experience were compared for events described with and without an odor. Participants (N = 106) were asked to imagine themselves becoming ill after engaging in several common experiences, including pumping gasoline at a service station. In two scenarios participants read that they smelled an offensive odor while pumping the gasoline whereas in two other scenarios no information about an odor was provided. Further, information about gasoline described with or without odor was presented either early or late in the stimulus paragraphs. All participants then responded to questions including an open-ended question asking them to make causal attributions for their illness. Participants in the odor-suggested group ascribed the cause of illness more frequently to gasoline and perceived the probability of other potential causes as lower than did participants in the nonodor suggested group. Findings suggest that peoples' implicit theories about toxicity contain causal connections between malodorous stimuli and illness. The implications of implicit theories for perception of illness are discussed.

Biases in perception and reporting following a perceived toxic exposure.

Reactions to chemical exposures often include fears of future illness, cancerphobia, reports of multiple chemical sensitivity, and other ill-defined complaints. Frequently, these complaints occur at levels of exposure not known to cause physiological harm. Although frequently dismissed as hysterical or hypochondriacal reactions, these complaints, along with other indefinite symptoms, may be better understood in terms of biases in perception and reporting. In this paper, we outline various sources of perceptual and response biases including prior beliefs, the media, influential others, reconstructed personal histories, self-perceptions, and the forensic environment. It is recommended that a thorough understanding of symptom-reporting and psychological distress following a chemical exposure involves consideration of these issues.

Neuropsychological false positives in litigation: trail making test findings.

100 workers' compensation claimants with no known history of brain injury and no claim for neuropsychological impairment were administered a generally accepted neuropsychological screening instrument, the Trail Making Test, to consider the possibility that the presence of litigation may be reflected in neuropsychological test scores. On Trails A and B, respectively, 40% and 36% of subjects scored in the impaired range. Clinicians are urged to interpret the results of the Trail Making Test cautiously when a patient is in litigation. Suggestions for research are offered.

Methodology in epidemiological studies of human neurobehavioral toxicity: a case study with critical review.

Health care professionals and government decision makers concerned with neurotoxicity increasingly rely on neuropsychological research studies. An example is an article relied upon by the U.S. Environmental Protection Agency that reported effects on neurobehavioral performance in a group of factory workers exposed to toluene by Foo, Jeyaratnam, and Koh in 1990, which is described as lacking reliability and as having implausible contents. A critical review can serve as an educational tool for neuropsychologists, to emphasize the need to design and document their research and interpret findings without speculation. For example, in the Foo, et al. study the implications of the findings for the general population cannot be interpreted. To conclude that this study has identified toluene as the cause of neurobehavioral deficits is a leap of inference far exceeding the power in their study. The review underscores the need for more critical reviews of research relied upon by decision makers and researchers.

Provisional normative data for a credibility scale for assessing personal injury claimants.

Preliminary normative data are presented for an experimental scale to assess credibility of personal injury claimants. The distinction between credibility and malingering and the need for credibility assessment in personal injury claims are discussed. Recommendations are made for use of the Credibility Scale.

Malingering emotional distress on the SCL-90-R: toxic exposure and cancerphobia.

This study reports that 100% of 52 untrained volunteers were able to fake psychopathology on the SCL-90-R at a level comparable to the average range for psychiatric patients. Although not questioning the nonforensic clinical usefulness of the instrument, the author cautions SCL-90-R users to employ the instrument with care in contexts in which deception is an issue. Data on efforts to fake cancerphobia and emotional distress secondary to toxic exposure are presented.

Malingering traumatic mental disorder on the Beck Depression Inventory: cancerphobia and toxic exposure.

The revised Beck Depression Inventory is widely used to measure severity of depression, and it is often used in personal injury litigation as evidence of trauma. However, the potential vulnerability of the inventory to malingering has not been assessed. Of a group of 52 untrained volunteers, 96% were able to fake depression on the inventory and 58% successfully faked extremely severe depression. Users are cautioned against treating Beck's inventory as a literal measuring instrument in contexts where manipulation of responses is a potential issue.

MMPI subtle-obvious scales and malingering: clinical versus simulated scores.

Subtle-obvious scale discrepancies on the Minnesota Multiphasic Personality Inventory were compared for pathology simulators and clinical groups to test the hypothesis that subtle-obvious scores help differentiate simulators. Total obvious minus subtle T score discrepancy greater than 100 discriminated the student malingerers and produced few false positives among clinical populations such as psychiatric inpatients and outpatients. The hypothesis that these clinical patients score high on these indices of malingering as a baserate or as a cry for help was rejected. These data suggest that there are differences between simulators and clinical patients, which are detectable by use of subtle-obvious scores, and that this procedure bears further exploration.

Fear of future illness, chemical AIDS, and cancerphobia: a review.

A review of the literature indicates that fear of future illness shares many characteristics with a wide variety of conditions. Concepts such as hypochondriasis, adjustment disorders, generalized anxiety, and mass hysteria must be considered. Also, factors such as reporting bias, influential others, collective behavior, political groups, and litigation appear to induce symptom reporting from patients complaining of fear of illness and cancerphobia. Cancerphobia may result in impairment ranging from avoidance behaviors to cognitive dysfunctions. Various treatment modalities have been used successfully in treating cancerphobia, and the prognosis is typically good. Complaints of chemical AIDS, universal allergy, or twentieth century disease have little medical or empirical support and require further investigation. Researchers and clinicians must recognize multiple factors contribute to fear of future illness or cancerphobic complaints, and additional research must be undertaken if a thorough understanding of fear of future illness, cancerphobia, and perceptions of chemical AIDS is to be obtained.

A Fake Bad Scale on the MMPI-2 for personal injury claimants.

This paper presents a scale for using the Minnesota Multiphasic Personality Inventory-2 for the detection of malingerers in personal injury claims. Data are reported for personal injury claimants and for medical outpatients simulating emotional distress caused by motor vehicle accidents, industrial stress, and toxic exposure. Criterion problems are discussed. The answers and scored directions are presented in an appendix to the paper.

Human response to traumatic events: an integration of counterfactual thinking, hindsight bias, and attribution theory.

In documenting cognitive processes underlying persons' reactions to negative events, counterfactual thinking, hindsight bias, and attribution theory focus on distinct, although not unrelated, aspects of human information processing. Counterfactual thinking highlights the cognitive processing undertaken when persons imagine different courses of action that lead to alternative outcomes. Hindsight bias describes the inflated retrospective estimates individuals make regarding event probabilities that come with the advantage of knowledge about outcomes. And attribution theory concerns the affective and behavioral consequences that result from the perceived causes of events. This essay argues that a more comprehensive understanding of the processes underlying human response to traumatic events results from the integration of counterfactual thinking, hindsight bias, and attribution theory into a single model.

Response bias in self-reported history of plaintiffs compared with nonlitigating patients.

Response bias refers to systematic error in the data produced by patients or research subjects, e.g., due to erroneous recall or reporting. In forensic settings, response bias appears to be associated with the nature of the proceedings. The present study tested whether patients in litigation exhibit different response patterns than nonlitigating patients when asked about their preinjury problems. 34 litigants and 80 nonlitigants rated various areas of cognitive and emotional functioning as problematic in the past and currently. The primary finding was that plaintiffs reported pre-injury functioning superior to that of controls. These findings suggest the need for caution in inferences that litigants are either reliable or deceitful because response biases may affect self-reports in a misleading fashion.