Malingering assessment after severe traumatic brain injury in forensic psychology with a potential embedded symptom validity indicator of Symptom Checklist 90

Objective

Malingering of neuropsychological damage is common among traumatic brain injury patients pursuing disability compensation in forensic contexts. There is an urgent need to explore differences in neuropsychological assessment outcomes with different levels of cooperation.

Methods

A total of 420 participants with severe traumatic brain injury were classified into malingering group, partial cooperation group, and complete cooperation group according to the Binomial forced-choice digit memory test. The Wechsler Adult Intelligence Scale, event-related potential component, and Symptom Checklist 90 were applied subsequently to assess the psychological status of participants.

Results

Participants in the malingering group presented lower scores in the binomial forced-choice digit memory test and the Wechsler Adult Intelligence Scale, lower P3 amplitude, and simultaneously higher scores in the Symptom Checklist 90 than the other two groups. The actual intelligence quotient of participants with malingering tendencies ranged mostly between normal and marginal damage, and they often reported elevated whole scale scores in the Symptom Checklist 90. The Cooperation Index (defined as the ratio of positive symptom distress index to global severity index, CI) was proposed and validated to function as an embedded validity indicator of the Symptom Checklist 90, and the area under the receiver operating characteristic (ROC) curve was 0.938. When valued at 1.28, CI has the highest classification ability in differentiating malingering from non-malingering. Combined with the CI and P3 amplitude, the area under the ROC curve for malingering diagnosis further reached 0.952.

Conclusion

Any non-optimal effort in a forensic context will lead to unexpected deviation in psychology evaluation results. CI is a potential candidate to act as an embedded validity indicator of the Symptom Checklist 90. The combination of CI and P3 amplitude can help to identify malingering in participants after severe traumatic brain injury.

The sensitivity of the IOP-29 and IOP-M to coached feigning of depression and mTBI: An online simulation study in a community sample from the United Kingdom

Assessing the credibility of symptoms is critical to neuropsychological assessment in both clinical and forensic settings. To this end, the Inventory of Problems-29 (IOP-29) and its recently added memory module (Inventory of Problems-Memory; IOP-M) appear to be particularly useful, as they provide a rapid and cost-effective measure of both symptom and performance validity. While numerous studies have already supported the effectiveness of the IOP-29, research on its newly developed module, the IOP-M, is much sparser. To address this gap, we conducted a simulation study with a community sample (N = 307) from the United Kingdom. Participants were asked to either (a) respond honestly or (b) pretend to suffer from mTBI or (c) pretend to suffer from depression. Within each feigning group, half of the participants received a description of the symptoms of the disorder to be feigned, and the other half received both a description of the symptoms of the disorder to be feigned and a warning not to over-exaggerate their responses or their presentation would not be credible. Overall, the results confirmed the effectiveness of the two IOP components, both individually and in combination.

Considerations regarding noncredible performance in the neuropsychological assessment of patients with multiple sclerosis: A case series

Determining the validity of data during clinical neuropsychological assessment is crucial for proper interpretation, and extensive literature has emphasized myriad methods of doing so in diverse samples. However, little research has considered noncredible presentation in persons with multiple sclerosis (pwMS). PwMS often experience one or more factors known to impact validity of data, including major neurocognitive impairment, psychological distress/psychogenic interference, and secondary gain. This case series aimed to illustrate the potential relationships between these factors and performance validity testing in pwMS. Six cases from an IRB-approved database containing pwMS referred for neuropsychological assessment at a large, academic medical center involving at least one of the above-stated factors were identified. Backgrounds, neuropsychological test data, and clinical considerations for each were reviewed. Interestingly, no pwMS diagnosed with major neurocognitive impairment was found to have noncredible performance, nor was any patient with noncredible performance in the absence of notable psychological distress. Given the variability of noncredible performance and multiplicity of factors affecting performance validity in pwMS, clinicians are strongly encouraged to consider psychometrically appropriate methods for evaluating validity of cognitive data in pwMS. Additional research aiming to elucidate base rates of, mechanisms begetting, and methods for assessing noncredible performance in pwMS is imperative.