Discriminating Feigned from Credible PTSD Symptoms: a Validation of a Brazilian Version of the Inventory of Problems-29 (IOP-29)

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.

Examining the cross-cultural validity of the test of memory malingering and the Rey 15-item test

OBJECTIVE

This study was designed to investigate the cross-cultural validity of two freestanding performance validity tests (PVTs), the Test of Memory Malingering - Trial 1 (TOMM-1) and the Rey Fifteen Item Test (Rey-15) in Romanian-speaking patients.

METHODS

The TOMM-1 and Rey-15 free recall (FR) and the combination score incorporating the recognition trial (COMB) were administered to a mixed clinical sample of 61 adults referred for cognitive evaluation, 24 of whom had external incentives to appear impaired. Average scores on PVTs were compared between the two groups. Classification accuracies were computed using one PVT against another.

RESULTS

Patients with identifiable external incentives to appear impaired produced significantly lower scores and more errors on validity indicators. The largest effect sizes emerged on TOMM-1 (Cohen's d = 1.00-1.19). TOMM-1 was a significant predictor of the Rey-15 COMB ≤20 (AUC = .80; .38 sensitivity; .89 specificity at a cutoff of ≤39). Similarly, both Rey-15 indicators were significant predictors of TOMM-1 at ≤39 as the criterion (AUCs = .73-.76; .33 sensitivity; .89-.90 specificity).

CONCLUSION

Results offer a proof of concept for the cross-cultural validity of the TOMM-1 and Rey-15 in a Romanian clinical sample.

Symptom coaching and symptom validity tests: An analog study using the structured inventory of malingered symptomatology, Self-Report Symptom Inventory, and Inventory of Problems-29

In this pilot and exploratory study, we tested the robustness of three self-report symptom validity tests (SVTs) to symptom coaching for depression, with and without additional information available on the Internet. Specifically, we divided our sample (N = 193) so that each subject received either the Structured Inventory of Malingered Symptomatology (SIMS; n = 64), the Self-Report Symptom Inventory (SRSI; n = 66), or the Inventory of Problems-29 (IOP-29; n = 63). Within each of the three subgroups, approximately one third of participants were instructed to respond honestly (Genuine Condition, nSIMS = 21; nSRSI = 24; nIOP-29 = 26) and approximately two-thirds were instructed to feign depression. One half of the feigners were presented with a vignette to increase their compliance with instructions and were given information about symptoms of depression (Coached Feigning, nSIMS = 25; nSRSI = 18; nIOP-29 = 21), and the other half were given the same vignette and information about symptoms of depression, plus two Internet links to review before completing the test (Internet-Coached Feigning, nSIMS = 18; nSRSI = 24; nIOP-29 = 16). Overall, the results showed that the genuine conditions yielded the lowest total scores on all three measures, while the two feigning conditions did not significantly differ from each other. Looking at the detection rates for all feigning participants, all three measures showed satisfactory results, with IOP-29 performing slightly better than SIMS and SIMS performing slightly better than SRSI. Internet-Coached Feigners scored slightly lower on all three measures than feigners who were coached without the Internet links. Taken together, the results of this preliminary and exploratory study suggest that all three SVTs examined are sensitive to feigned depression even in the presence of symptom coaching, both with and without additional Internet-based information.

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.

Using the MMPI-2-RF, IOP-29, IOP-M, and FIT in the In-Person and Remote Administration Formats: A Simulation Study on Feigned mTBI

Our study compared the impact of administering Symptom Validity Tests (SVTs) and Performance Validity Tests (PVTs) in in-person versus remote formats and assessed different approaches to combining validity test results. Using the MMPI-2-RF, IOP-29, IOP-M, and FIT, we assessed 164 adults, with half instructed to feign mild traumatic brain injury (mTBI) and half to respond honestly. Within each subgroup, half completed the tests in person, and the other half completed them online via videoconferencing. Results from 2 ×2 analyses of variance showed no significant effects of administration format on SVT and PVT scores. When comparing feigners to controls, the MMPI-2-RF RBS exhibited the largest effect size (d = 3.05) among all examined measures. Accordingly, we conducted a series of two-step hierarchical logistic regression models by entering the MMPI-2-RF RBS first, followed by each other SVT and PVT individually. We found that the IOP-29 and IOP-M were the only measures that yielded incremental validity beyond the effects of the MMPI-2-RF RBS in predicting group membership. Taken together, these findings suggest that administering these SVTs and PVTs in-person or remotely yields similar results, and the combination of MMPI and IOP indexes might be particularly effective in identifying feigned mTBI.

Detection of Feigning of Different Symptom Presentations With the PAI and IOP-29

This study examined the effectiveness of the negative distortion measures from the Personality Assessment Inventory (PAI) and Inventory of Problems-29 (IOP-29), by investigating data from a community and a forensic sample, across three different symptom presentations (i.e., feigned depression, posttraumatic stress disorder [PTSD], and schizophrenia). The final sample consisted of 513 community-based individuals and 288 inmates (total N = 801); all were administered the PAI and the IOP-29 in an honest or feigning conditions. Statistical analyses compared the average scores of each measure by symptom presentation and data source (i.e., community vs. forensic sample) and evaluated diagnostic efficiency statistics. Results suggest that the PAI Negative Impression Management scale and the IOP-29 are the most effective measures across all symptom presentations, whereas the PAI Malingering Index and Rogers Discriminant Function generated less optimal results, especially when considering feigned PTSD. Practical implications are discussed.

On the Use of Eye Movements in Symptom Validity Assessment of Feigned Schizophrenia

Assessing the credibility of reported mental health problems is critical in a variety of assessment situations, particularly in forensic contexts. Previous research has examined how the assessment of performance validity can be improved through the use of bio-behavioral measures (e.g., eye movements). To date, however, there is a paucity of literature on the use of eye tracking technology in assessing the validity of presented symptoms of schizophrenia, a disorder that is known to be associated with oculomotor abnormalities. Thus, we collected eye tracking data from 83 healthy individuals during the completion of the Inventory of Problems – 29 and investigated whether the oculomotor behavior of participants instructed to feign schizophrenia would differ from those of control participants asked to respond honestly. Results showed that feigners had a longer dwell time and a greater number of fixations in the feigning-keyed response options, regardless of whether they eventually endorsed those options (d > 0.80). Implications on how eye tracking technology can deepen comprehension on simulation strategies are discussed, as well as the potential of investigating eye movements to advance the field of symptom validity assessment.

Take Their Word for It: The Inventory of Problems Provides Valuable Information on Both Symptom and Performance Validity

This study was designed to compare the validity of the Inventory of Problems (IOP-29) and its newly developed memory module (IOP-M) in 150 patients clinically referred for neuropsychological assessment. Criterion groups were psychometrically derived based on established performance and symptom validity tests (PVTs and SVTs). The criterion-related validity of the IOP-29 was compared to that of the Negative Impression Management scale of the Personality Assessment Inventory (NIM_PAI) and the criterion-related validity of the IOP-M was compared to that of Trial-1 on the Test of Memory Malingering (TOMM-1). The IOP-29 correlated significantly more strongly (z = 2.50, p = .01) with criterion PVTs than the NIM_PAI (r_IOP-29 = .34; r_NIM-PAI = .06), generating similar overall correct classification values (OCC_IOP-29: 79-81%; OCC_NIM-PAI: 71-79%). Similarly, the IOP-M correlated significantly more strongly (z = 2.26, p = .02) with criterion PVTs than the TOMM-1 (r_IOP-M = .79; r_TOMM-1 = .59), generating similar overall correct classification values (OCC_IOP-M: 89-91%; OCC_TOMM-1: 84-86%). Findings converge with the cumulative evidence that the IOP-29 and IOP-M are valuable additions to comprehensive neuropsychological batteries. Results also confirm that symptom and performance validity are distinct clinical constructs, and domain specificity should be considered while calibrating instruments.

Failing Performance Validity Cutoffs on the Boston Naming Test (BNT) Is Specific, but Insensitive to Non-Credible Responding

This study was designed to examine alternative validity cutoffs on the Boston Naming Test (BNT).Archival data were collected from 206 adults assessed in a medicolegal setting following a motor vehicle collision. Classification accuracy was evaluated against three criterion PVTs.The first cutoff to achieve minimum specificity (.87-.88) was T ≤ 35, at .33-.45 sensitivity. T ≤ 33 improved specificity (.92-.93) at .24-.34 sensitivity. BNT validity cutoffs correctly classified 67-85% of the sample. Failing the BNT was unrelated to self-reported emotional distress. Although constrained by its low sensitivity, the BNT remains a useful embedded PVT.

Symptom and Performance Validity Assessment in European Countries: an Update

In 2013, a special issue of the Spanish journal Clínica y Salud published a review on symptom and performance validity assessment in European countries (Merten et al. in Clínica y Salud, 24(3), 129–138, 2013). At that time, developments were judged to be in their infancy in many countries, with major publication activities stemming from only four countries: Spain, The Netherlands, Great Britain, and Germany. As an introduction to a special issue of Psychological Injury and Law, this is an updated report of developments during the last 10 years. In that period of time, research activities have reached a level where it is difficult to follow all developments; some validity measures were newly developed, others were adapted for European languages, and validity assessment has found a much stronger place in real-world evaluation contexts. Next to an update from the four nations mentioned above, reports are now given from Austria, Italy, and Switzerland, too.

Detecting Negative Response Bias Within the Trauma Symptom Inventory–2 (TSI-2): a Review of the Literature

This systematic review was performed to summarize existing research on the symptom validity scales within the Trauma Symptom Inventory–Second Edition (TSI-2), a relatively new self-report measure designed to assess the psychological sequelae of trauma. The TSI-2 has built-in symptom validity scales to monitor response bias and alert the assessor of non-credible symptom profiles. The Atypical Response scale (ATR) was designed to identify symptom exaggeration or fabrication. Proposed cutoffs on the ATR vary from ≥ 7 to ≥ 15, depending on the assessment context. The limited evidence available suggests that ATR has the potential to serve as measure of symptom validity, although its classification accuracy is generally inferior compared to well-established scales. While the ATR seems sufficiently sensitive to symptom over-reporting, significant concerns about its specificity persist. Therefore, it is proposed that the TSI-2 should not be used in isolation to determine the validity of the symptom presentation. More research is needed for development of evidence-based guidelines about the interpretation of ATR scores.