A systematic review and meta-analysis of the Test of Memory Malingering in adults: Two decades of deception detection

A Meta-Analysis of Neuropsychological Effort Test Performance in Psychotic Disorders

Psychotic disorders are characterized by a generalized neurocognitive deficit (i.e., performance 1.5 SD below controls across neuropsychological domains with no specific profile of differential deficits). A motivational account of the generalized neurocognitive deficit has been proposed, which attributes poor neuropsychological testing performance to low effort. However, findings are inconsistent regarding effort test failure rate in individuals with psychotic disorders across studies (0-72%), and moderators are unclear, making it difficult to know whether the motivational explanation is viable. To address these issues, a meta-analysis was performed on data from 2205 individuals with psychotic disorders across 19 studies with 24 independent effects. Effort failure rate was examined along with moderators of effort test type, forensic status, IQ, positive symptoms, negative symptoms, diagnosis, age, gender, education, and antipsychotic use. The pooled weighted effort test failure rate was 18% across studies and there was a moderate pooled association between effort failure rate and global neurocognitive performance (r = .57). IQ and education significantly moderated failure rate. Collectively, these findings suggest that a nontrivial proportion of individuals with a psychotic disorder fail effort testing, and failure rate is associated with global neuropsychological impairment. However, given that effort tests are not immune to the effects of IQ in psychotic disorders, these results cannot attest to the viability of the motivational account of the generalized neurocognitive deficit. Furthermore, the significant moderating effect of IQ and education on effort test performance suggests that effort tests have questionable validity in this population and should be interpreted with caution.

Early Cutoff Criteria for Strong Performance on the Test of Memory Malingering

OBJECTIVE

The Test of Memory Malingering (TOMM) is widely used to assess performance validity. To improve efficiency, we investigated whether abbreviated administration (i.e., only the first 25 items of Trial 1 [T1]) is possible when effort is very strong (≥49/50 on T1 or T2).

METHOD

We collected TOMM scores of 501 consecutive adult patients ranging in cognitive status who underwent standard neuropsychological evaluation at Mayo Clinic, Rochester, MN.

RESULTS

Receiver Operating Characteristic (ROC) analysis showed excellent area under the curve (AUC) (0.94; CI95% [0.92, 0.97]) and a cutoff of 25/25 had 100% specificity for identifying strong performance. Of the 224 patients who obtained a perfect score on the first 25 items, 197 (88%) obtained ≥49 on T1 and the remaining patients (n = 27) obtained ≥49 on T2.

CONCLUSION

A perfect score on the first 25 items of the TOMM predicted overall strong performance 100% of the time, supporting abbreviated administration in select cases in a general outpatient clinical setting.

Feedback with patients who produce invalid testing: Professional values and reported practices

OBJECTIVE

Providing feedback to clinical patients who produce invalid neuropsychological test data presents with several potential challenges. Given the limited guidance available on the topic, neuropsychologists most likely utilize approaches that idiosyncratically incorporate professional values related to both assessment and patient care to address overarching feedback goals. The current article discusses professional values believed to inform feedback decisions and presents survey results regarding how neuropsychologists would approach feedback across various clinical scenarios where testing is invalid.

METHOD

Participants were 209 adult-focused clinical neuropsychologists recruited via professional listservs, the majority of whom reported being board certified. Respondents were provided three case vignettes of clinical patients who produced invalid test data and were asked how they would provide feedback to each patient. Open-ended responses were coded to determine the relative frequency of feedback approaches, explicit statements, and implied goals.

RESULTS

Nearly all respondents (98%) indicated that feedback would include some description of the invalid findings, and most respondents indicated that they would provide explanations for the reasons of invalidity (67%) and statements regarding the impact of invalidity on test interpretation (75%). There was little agreement across respondents, however, regarding specific feedback approach. Feedback goals included to Inform, Investigate, Treat, Educate, and Correct, with the presence of these implied goals also varying across respondents.

CONCLUSIONS

The findings indicate that there is minimal consensus regarding feedback approaches provided to patients who produce invalid test data and underscore a need for further development and validation of specific feedback methods. The results are discussed within the context of the potentially competing professional values of evidence-based assessment, patient-doctor collaboration, and aspirational principles of beneficence and fidelity.

The validity of the test of memory malingering (TOMM) with deaf individuals

OBJECTIVE

Administration of performance validity tests (PVT) during neuropsychological assessments is standard practice, with the Test of Memory Malingering (TOMM) being a commonly used measure. The TOMM has been well validated in hearing populations with various medical and psychiatric backgrounds. A major gap in the literature is the use of the TOMM amongst culturally Deaf individuals who use American Sign Language (ASL) as their first and preferred language. The purpose of this study was to explore the use of the TOMM with this population to determine if there may be differences related to the use of semantic knowledge and recall using signs rather than spoken phonemes.

METHOD

This study recruited 30 culturally Deaf, community-dwelling adults, who self-reported that they were not involved in litigation ordisability claims. In addition to the TOMM, participants were screened for cognitive ability using non-verbal components of the Wechsler Abbreviated Scale of Intelligence, Second Edition (WASI-II) and the Mini Mental State Examination: ASL Version (MMSE:ASL).

RESULTS

Nonverbal intelligence for this sample was within the average range of ability. No participants scored lower than the standard cut-off score for Trial 2 or the Retention Trial on the TOMM (≤44 raw score to indicate invalid responding). Trial 1 performances ranged from 44 to 50, Trial 2 performances ranged from 49 to 50, and Retention performances ranged from 49 to 50.

CONCLUSION

These results support the use of the same standard cut-off scores established for hearing individuals in culturally Deaf individuals who use ASL.

Cross-validation of the Invalid Forgetting Frequency Index (IFFI) from the Test of Memory Malingering

Objective

To increase sensitivity of the Test of Memory Malingering (TOMM), adjustments have been proposed, including adding consistency indices. The Invalid Forgetting Frequency Index (IFFI) is the most recently developed consistency index. While strong classification accuracy rates were originally reported, it currently lacks cross-validation.

Method

A sample of 184 outpatients was utilized. Valid performers passed all criterion performance validity tests (PVTs) and invalid performers failed two or more PVTs. Classification accuracy statistics were calculated.

Results

AUC for the IFFI was 0.80, demonstrating adequate discrimination between valid and invalid groups. A score of 3 or more inconsistent responses resulted in sensitivity and specificity rates of 63% and 92%, respectively.

Conclusions

This is the first article to cross-validate the IFFI. In both the original IFFI study and the current study, the same cut-off was found to maintain at least 90% specificity while producing higher sensitivity rates than those achieved by traditional TOMM indices.