The effect of coaching on the simulated malingering of memory impairment

BMC Neurology The effect of coaching on the simulated malingering of memory impairment Jascha Rsseler 1 2 3 Alexandra Brett 2 Ulrike Klaue 0 2 Michael Sailer 0 4 Thomas F Mnte 1 2 0 Median Klinik NRZ , Magdeburg , Germany 1 Center for Behavioral Brain Sciences , Magdeburg , Germany 2 Department of Psychology II, Neuropsychology Unit, Otto-von-Guericke University Magdeburg , Germany 3 Institut fur Psychologie II , Abt. Neuropsychologie, Postfach 4120, 39016 Magdeburg , Germany 4 Klinik fur Neurologie II, Otto-von-Guericke University Magdeburg , Germany Background: Detecting malingering or exaggeration of impairments in brain function after traumatic brain injury is of increasing importance in neuropsychological assessment. Lawyers involved in brain injury litigation cases routinely coach their clients how to approach neuropsychological testing to their advantage. Thus, it is important to know how robust assessment methods are with respect to symptom malingering or exaggeration. Methods: The influence of different coaching methods on the simulated malingering of memory impairments is investigated in neurologically healthy participants using the Short-Term-Memory Test from the Bremer Symptom-Validierung (STM-BSV). Cut-offs were derived from patients with mild to severe traumatic brain injury. For comparison purposes, the German adaptation of the Rey Auditory Verbal Learning Test (AVLT), and the Rey 15 Items Test (FIT) were additionally administered. Four groups of neurologically healthy subjects were instructed to (1) perform as best as they can, (2) simulate brain injury, (3) simulate brain injury and received additional information about the sequelae of head trauma, (4) simulate brain injury and received additional information on how to avoid detection. Furthermore, a group of patients with mild to severe closed head injury performed the tests with best effort. Results: The nave simulator and the symptom coached groups were the easiest to detect, whereas the symptom plus test coached group was the hardest to detect. The AVLT and the FIT were not suited to detect simulators (sensitivities from 0% to 50.8% at 75% specificity) whereas the STM-BSV detected simulators with 67% - 88% sensitivity at a specificity of 73%. However, the STM-BSV was not robust to coaching. Conclusion: The present investigation shows that symptom validity testing as implemented in the BSV-STM is one clinically useful element in the detection of memory malingering. However, clinicians have to be aware that coaching influences performance in the test. - Background The detection of malingering or exaggeration of impairments in brain function is of increasing importance in clinical neuropsychological assessment. In a forensic setting, an estimated 70% or more of patients assessed by clinical neuropsychologists are suspected to alter their presentations [1,2]. Memory impairment is one common symptom of brain injury that is well-known to laypersons. For example, 82% of the general public are aware that a concussion often results in memory problems [3]. Individuals who attempt to malinger head trauma symptoms often report a variety of memory difficulties [4] and perform poorly on memory tests [5]. Patients with brain injury also often complain of difficulties to remember things [6], and their performance on memory tests is impaired [7]. It is considered standard practice for neuropsychologists in North America to use measures for malingering detection routinely [8-10]. In contrast, effort testing has had limited impact on clinical practice in European countries. Notable exceptions are the Amsterdam Short-Term Memory Test [11], adaptations of Green's Word Memory Test [12] to several European languages, and the "Testbatterie zur Forensischen Neuropsychologie" (TBFN; [13]). The TBFN contains 23 tests specifically designed to detect malingering (a computerized version of Rey's 15 Item Test, FIT [14]; an auditory analog version of Rey's 15 Item Test; two tests for the assessment of memory in everyday life; the Bremer Symptom-Validierung, BSV: 19 symptom validity tests to assess perceptual and mnestic impairments). The present study uses an analog design to evaluate the usefulness of the BSV short-term memory assessment subtest, the FIT and the VLMT (Verbaler Lernund Merkfhigkeitstest [15], German adaptation of Rey's Auditory Verbal Learning Test) to detect malingering of memory impairment. Furthermore, the effects of different coaching procedures on classification rates are investigated. Approaches for the detection of memory malingering Three basic approaches for malingering detection have been proposed: looking for inconsistencies in test results [16], the use of tests specifically designed to detect incomplete effort, and the application of cut-off values derived from standard neuropsychological tests. The most-widely used groups of tests specifically designed to detect incomplete effort are (a) tests that appear to be more difficult than is actually the case (e.g., FIT), and (b) the symptom validity technique. Tests appearing more difficult than they actually are The FIT is introduced as a very difficult memory test as it requires to remember 15 different items in a short time. In fact, the test is very simple because of the redundancy among the items, and patients with significant brain impairment can perform the test without much difficulty. The rationale of the test assumes that malingerers are unaware of this fact and reason that, in order to be categorized as memory impaired, they will have to recall only a few items. Thus, patients with brain impairment will do well on the FIT, whereas malingerers perform poorly and can thus be identified [17-19]. Symptom validity testing In the symptom validity technique, each item has a 50% probability of obtaining a correct response when guessing. Theoretically, a person scoring below chance is most likely malingering. Prominent examples of this technique are the Test of Memory Malingering (TOMM; [20]), and the Portland Digit Recognition Test, [21]). Symptom validity tests require that participants believe that they have to perform a difficult task. If the malingerer does not realize that the task is easy, he will perform poorly. However, if the patient notices that the task is easy, he might recognize the attempt to detect malingering and, thus, perform normally on the task. In this context, it is interesting that 48% of US lawyers believe that they should provide information about psychological tests to their clients [22], and that lawyers involved in brain injury litigation cases indeed do this regularly [23]. Furthermore, the internet provides an easily accessible source of information about tests of malingering detection that can be used by patients to prepare themselves for a neuropsychological assessment [24]. Thus, litigants may well be aware of the rationale of symptom validity testing. Standard memory tests One approach to overcome these c (...truncated)