Symptom and Performance Validity Assessment in European Countries: an Update

Classification accuracy and resistance to coaching of the Spanish version of the Inventory of Problems-29 and the Inventory of Problems-Memory: A simulation study with mTBI patients

Objective: The present study aims to evaluate the classification accuracy and resistance to coaching of the Inventory of Problems-29 (IOP-29) and the IOP-Memory (IOP-M) with a Spanish sample of patients diagnosed with mild traumatic brain injury (mTBI) and healthy participants instructed to feign. Method: Using a simulation design, 37 outpatients with mTBI (clinical control group) and 213 non-clinical instructed feigners under several coaching conditions completed the Spanish versions of the IOP-29, IOP-M, Structured Inventory of Malingered Symptomatology, and Rivermead Post Concussion Symptoms Questionnaire. Results: The IOP-29 discriminated well between clinical patients and instructed feigners, with an excellent classification accuracy for the recommended cutoff score (FDS ≥ .50; sensitivity = 87.10% for coached group and 89.09% for uncoached; specificity = 95.12%). The IOP-M also showed an excellent classification accuracy (cutoff ≤ 29; sensitivity = 87.27% for coached group and 93.55% for uncoached; specificity = 97.56%). Both instruments proved to be resistant to symptom information coaching and performance warnings. Conclusions: The results confirm that both of the IOP measures offer a similarly valid but different perspective compared to SIMS when assessing the credibility of symptoms of mTBI. The encouraging findings indicate that both tests are a valuable addition to the symptom validity practices of forensic professionals. Additional research in multiple contexts and with diverse conditions is warranted.

Validity assessment in Eastern Europe: cross-validation of the Dot Counting Test and MODEMM against the TOMM-1 and Rey-15 in a Romanian mixed clinical sample

OBJECTIVE

This study investigated performance validity in the understudied Romanian clinical population by exploring classification accuracies of the Dot Counting Test (DCT) and the first Romanian performance validity test (PVT) (Memory of Objects and Digits and Evaluation of Memory Malingering/MODEMM) in a heterogeneous clinical sample.

METHODS

We evaluated 54 outpatients (26 females; MAge = 62.02; SDAge = 12.3; MEducation = 2.41, SDEducation = 2.82) with the Test of Memory Malingering 1 (TOMM-1), Rey Fifteen Items Test (Rey-15) (free recall and recognition trials), DCT, MODEMM, and MMSE/MoCA as part of their neuropsychological assessment. Accuracy parameters and base failure rates were computed for the DCT and MODEMM indicators against the TOMM-1 and Rey-15. Two patient groups were constructed according to psychometrically defined credible/noncredible performance (i.e., pass/fail both TOMM-1 and Rey-15).

RESULTS

Similar to other cultures, a cutoff of ≥18 on the DCT E score produced the best combination between sensitivity (0.50-0.57) and specificity (≥0.90). MODEMM indicators based on recognition accuracy, inconsistencies, and inclusion false positives generated 0.75-0.86 sensitivities at ≥0.90 specificities. Multivariable models of MODEMM indicators reached perfect sensitivities at ≥0.90 specificities against two PVTs. Patients who failed the TOMM-1 and Rey-15 were significantly more likely to fail the DCT and MODEMM than patients who passed both PVTs.

CONCLUSIONS

Our results offer proof of concept for the DCT's cross-cultural validity and the applicability of the MODEMM on Romanian clinical examinees, further recommending the use of heterogeneous validity indicators in clinical assessments.

Two Cases of Malingered Crime-Related Amnesia

Amnesia is a frequent claim in major crimes, and it is estimated that the complete or partial absence of memory following a crime ranges from 25% to 50% of total cases. Although some cases may constitute a genuine form of amnesia, due to organic-neurological defects or psychological causes, and possibly combined with a dissociative or repressive coping style after an extreme experience, malingering is still fairly common in offenders. Therefore, one of the main goals in medico-legal proceedings is to find methods to determine the credibility of crime-related amnesia. At present, a number of lie and memory detection techniques can assist the forensic assessment of the reliability of declarative proof, and have been devised and improved over the past century: for example, modern polygraphs, event-related potentials, thermal imaging, functional magnetic resonance imaging, kinematic, and facial analysis. Other ad hoc psychological tests, such as the so-called Symptom Validity Test (SVT) and Performance Validity Test (PVT), as well as the autobiographical Implicit Association Test (aIAT), can also be used. To date, however, there is little evidence or case reports that document their real usefulness in forensic practice. Here, we report two cases of crime-related amnesia, whereby both defendants, who were found guilty of homicide, appeared to exhibit dissociative amnesia but where the application of SVTs, PVTs, and aIAT detected a malingered amnesia.

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.

Attention Performance as an Embedded Validity Indicator in the Cognitive Assessment of Early Retirement Claimants

The assessment of performance validity is essential in any neuropsychological evaluation. However, relatively few measures exist that are based on attention performance embedded within routine cognitive tasks. The present study explores the potential value of a computerized attention test, the Cognitrone, as an embedded validity indicator in the neuropsychological assessment of early retirement claimants. Two hundred and sixty-five early retirement claimants were assessed with the Word Memory Test (WMT) and the Cognitrone. WMT scores were used as the independent criterion to determine performance validity. Speed and accuracy measures of the Cognitrone were analyzed in receiver operating characteristics (ROC) to classify group membership. The Cognitrone was sensitive in revealing attention deficits in early retirement claimants. Further, 54% (n = 143) of the individuals showed noncredible cognitive performance, whereas 46% (n = 122) showed credible cognitive performance. Individuals failing the performance validity assessment showed slower (AUC = 79.1%) and more inaccurate (AUC = 79.5%) attention performance than those passing the performance validity assessment. A compound score integrating speed and accuracy revealed incremental value as indicated by AUC = 87.9%. Various cut scores are suggested, resulting in equal rates of 80% sensitivity and specificity (cut score = 1.297) or 69% sensitivity with 90% specificity (cut score = 0.734). The present study supports the sensitivity of the Cognitrone for the assessment of attention deficits in early retirement claimants and its potential value as an embedded validity indicator. Further research on different samples and with multidimensional criteria for determining invalid performance are required before clinical application can be suggested.