RESUMO
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.
RESUMO
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.
