The utility of the Structured Inventory of Malingered Symptomatology for distinguishing individuals with Dissociative Identity Disorder (DID) from DID simulators and healthy controls

• Published in: European journal of psychotraumatology Vol. 12; no. 1; p. 1984048
• Main Authors: Brand, Bethany L., Barth, Michelle, Schlumpf, Yolanda R., Schielke, Hugo, Chalavi, Sima, Vissia, Eline M., Nijenhuis, Ellert R. S., Jäncke, Lutz, Reinders, Antje A. T. S.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01-01-2021; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Adult; Clinical; disociación; dissociation; Dissociative disorders; Dissociative Identity Disorder - diagnosis; exageración; exaggeration; feigning; Female; fingimiento; hacerse el enfermo; Humans; Inventario Estructurado de Sintomatología Maligna; Male; malingering; Malingering - diagnosis; Middle Aged; Neuropsychological Tests - standards; Personality disorders; Psychology; SIMS; simulación; simulation; Structured Inventory of Malingered Symptomatology; Trauma; Young Adult; 诈病症状学结构化问卷; exaggeration; trauma; Structured Inventory of Malingered Symptomatology; dissociation; simulation; feigning; malingering; SIMS
• ISSN: 2000-8066; 2000-8198; 2000-8066
• DOI: 10.1080/20008198.2021.1984048

Background: Individuals with dissociative identity disorder (DID) have complex symptoms consistent with severe traumatic reactions. Clinicians and forensic assessors are challenged by distinguishing symptom exaggeration and feigning from genuine symptoms among these individuals. This task may be aided by administering validity measures.
Objective: This study aimed to document how individuals with DID score on the Structured Inventory of Malingered Symptomatology (SIMS). The second objective was to compare coached DID simulators and healthy controls to DID patients on the SIMS's total score and subscales. The third objective was to examine the utility rates of the SIMS in distinguishing simulated DID from clinically diagnosed DID.
Method: We compared SIMS data gathered from participants from two Dutch sites, one Swiss site and one U.S. site. Sixty-three DID patients were compared to 77 coached DID simulators and 64 healthy controls on the SIMS. A multivariate analysis compared the groups on the SIMS total scores and subscales, and post-hoc Games Howell tests and univariate ANOVAs examined differences between the groups. Utility statistics assessed the accuracy of the SIMS in distinguishing clinical from simulated DID.
Results: DID simulators scored significantly higher than DID individuals and healthy controls on every SIMS subscale as well as the total score. The majority (85.7%) of the individuals with DID scored above the cut-off, which is typically interpreted as indicative of possible symptom exaggeration. DID individuals scored higher than the healthy controls on every subscale except Low Intelligence, even after controlling for dissociation. The subscales and items most frequently endorsed by the DID group are consistent with symptoms associated with complex trauma exposure and dissociative reactions. The SIMS total score had a sensitivity of 96% but an unacceptably low specificity of 14%.
Conclusions: The findings indicate that the instrument is not accurate in assessing potential symptom exaggeration or feigning in DID.
The malingering screen, Structured Inventory of Malingered Symptomatology (SIMS), cannot accurately distinguish SIMS data collected from DID patients compared to DID feigners.
The items endorsed by the DIDs are consistent with symptoms associated with complex trauma exposure.