Performance and symptom validity testing in neuropsychological assessments in Australia: a survey of practises and beliefs

Prevalence Estimates of Symptom Feigning and Malingering in Spain

Symptom feigning and malingering should be evaluated in forensic contexts due to their important socio-economic consequences. Despite this, to date, there is little research in Spain that evaluates its prevalence. The aim of this study was to investigate this issue using the perception of the general population, students, and professionals of medicine and forensic psychology. Three adapted questionnaires were applied to a total of 1003 participants (61.5% women) from 5 different groups. Approximately two-thirds of participants reported knowing someone who feigned symptoms, and one-third disclosed feigning symptoms themselves in the past. Headache/migraine, neck pain, and anxious-depressive symptoms were the most commonly chosen. Experts in psychology and forensic medicine estimated a prevalence of 20 to 40% of non-credible symptom presentations in their work settings and reported not having sufficient means to assess the distorted presentation of symptoms with certainty. Professionals and laypersons alike acknowledge that non-credible symptom presentations (like feigning or malingering) are relevant in Spain and occur at a non-trivial rate, which compares with estimates in other parts of the world.

What are the predictors of TOMM failure in clinical TBI populations? A retrospective analysis

OBJECTIVES

To determine base rates of invalid performance on the Test of Memory Malingering (TOMM) in patients with traumatic brain injury (TBI) undertaking rehabilitation who were referred for clinical assessment, and the factors contributing to TOMM failure.

METHODS

Retrospective file review of consecutive TBI referrals for neuropsychological assessment over seven years. TOMM failure was conventionally defined as performance <45/50 on Trial 2 or Retention Trial. Demographic, injury, financial compensation, occupational, and medical variables were collected.

RESULTS

Four hundred and ninety one TBI cases (Median age = 40 years [IQR = 26-52], 79% male, 82% severe TBI) were identified. Overall, 48 cases (9.78%) failed the TOMM. Logistic regression analyses revealed that use of an interpreter during the assessment (adjusted odds ratio [aOR] = 8.25, 95%CI = 3.96-17.18), outpatient setting (aOR = 4.80, 95%CI = 1.87-12.31) and post-injury psychological distress (aOR = 2.77, 95%CI = 1.35-5.70) were significant multivariate predictors of TOMM failure. The TOMM failure rate for interpreter cases was 49% (21/43) in the outpatient setting vs. 7% (2/30) in the inpatient setting. By comparison, 9% (21/230) of non-interpreter outpatient cases failed the TOMM vs. 2% (4/188) of inpatient cases.

CONCLUSIONS

TOMM failure very rarely occurs in clinical assessment of TBI patients in the inpatient rehabilitation setting. It is more common in the outpatient setting, particularly in non-English-speaking people requiring an interpreter. The findings reinforce the importance of routinely administering stand-alone performance validity tests in assessments of clinical TBI populations, particularly in outpatient settings, to ensure that neuropsychological test results can be interpreted with a high degree of confidence.

Objective Cognitive Outcomes and Subjective Emotional Sequelae in Litigating Adults with a Traumatic Brain Injury: The Impact of Performance and Symptom Validity Measures

OBJECTIVE

This study examined the relative contribution of performance and symptom validity in litigating adults with traumatic brain injury (TBI), as a function of TBI severity, and examined the relationship between self-reported emotional symptoms and cognitive tests scores while controlling for validity test performance.

METHOD

Participants underwent neuropsychological assessment between January 2012 and June 2021 in the context of compensation-seeking claims related to a TBI. All participants completed a cognitive test battery, the Personality Assessment Inventory (including symptom validity tests; SVTs), and multiple performance validity tests (PVTs). Data analyses included independent t-tests, one-way ANOVAs, correlation analyses, and hierarchical multiple regression.

RESULTS

A total of 370 participants were included. Atypical PVT and SVT performance were associated with poorer cognitive test performance and higher emotional symptom report, irrespective of TBI severity. PVTs and SVTs had an additive effect on cognitive test performance for uncomplicated mTBI, but less so for more severe TBI. The relationship between emotional symptoms and cognitive test performance diminished substantially when validity test performance was controlled, and validity test performance had a substantially larger impact than emotional symptoms on cognitive test performance.

CONCLUSION

Validity test performance has a significant impact on the neuropsychological profiles of people with TBI, irrespective of TBI severity, and plays a significant role in the relationship between emotional symptoms and cognitive test performance. Adequate validity testing should be incorporated into every neuropsychological assessment, and associations between emotional symptoms and cognitive outcomes that do not consider validity testing should be interpreted with extreme caution.