Utility of cognitive malingering measures in a forensic psychiatric sample

Debbie Green, Fordham University

Abstract

Despite the motivations within forensic psychiatric evaluations for defendants to feign cognitive deficits (e.g., memory and concentration problems, low intelligence), there is virtually no research that has assessed the utility of cognitive malingering measures in forensic settings. Consequently, there are few guidelines to inform psychologists about the utility of these measures to detect malingering, the impact of psychiatric symptoms and level of intelligence on the accuracy of these measures, nor how the results from measures of malingered mental disorders and malingered cognitive deficits should be integrated. This study evaluated the ability of the Test of Memory Malingering (TOMM), Validity Indicator Profile-Verbal Subtest (VIP-V), Rey Fifteen Item Memory Test (FIT), and the Dot Counting Test (DCT) to differentiate 93 genuine pre-trial forensic patients hospitalized for restoration of competency to stand trial from 25 forensic patients presumed to be feigning incompetency and 36 community participants simulating incompetency. Results of the measures were compared with that obtained from the Structured Interview of Reported Symptoms (SIRS) and evaluated to determine the relationship between scores and performance on the Wechsler Abbreviated Scale of Intelligence (WASI) and the Brief Psychiatric Rating Scale-Expanded (BPRS-E). Using established cut-offs, over 80% of genuine forensic psychiatric patients were accurately classified by the TOMM, FIT, and DCT, displaying equivalent specificity as the SIRS. The VIP-V generated higher false positive rates; however, many genuine patients were classified as Careless, indicating that they were motivated to do well. The measures identified approximately half of suspected and simulating malingerers, with slightly higher rates in the latter sample. Level of intelligence significantly impacted scores and specificity rates on each of the cognitive malingering measures, although the TOMM remained fairly accurate among patients with at least Borderline intelligence. Severity of psychiatric symptoms and diagnoses did not impact results on any of the cognitive malingering measures. Several methods of integrating test results were evaluated, with the TOMM and the DCT displaying incremental accuracy over the SIRS used in isolation. The optimal method combined results of the SIRS, TOMM, and DCT, generating over 90% specificity and 40–55% sensitivity in the malingering groups. Additional research to evaluate the generalizability of findings to other forensic contexts, better understand the impact of intelligence, and determine alternative combinations of measures (including personality assessments) is clearly warranted.

Subject Area

Clinical psychology|Criminology|Quantitative psychology

Recommended Citation

Green, Debbie, "Utility of cognitive malingering measures in a forensic psychiatric sample" (2010). ETD Collection for Fordham University. AAI3438475.
https://research.library.fordham.edu/dissertations/AAI3438475

Share

COinS