Detecting clinical and simulated dissociative identity disorder with the Test of Memory Malingering.

Abstract

Few studies have assessed malingering in individuals with complex trauma and dissociation. This is concerning because these individuals' severe and ranging symptoms are associated with elevations on some, but not all, validity scales that detect symptom exaggeration. Dissociative individuals may experience dissociative amnesia, yet no study to date has examined how to distinguish clinical from malingered amnesia with dissociative samples. The current study examined whether the Test of Memory Malingering (TOMM) can accurately distinguish patients with clinically diagnosed dissociative identity disorder (DID) and simulators coached to imitate DID. Utility statistics classify individuals' TOMM scores as suggestive of clinical or simulated DID. TOMM scores from 31 patients diagnosed with DID via structured interviews were compared to those of 74 coached DID simulators. Discriminant analyses found scores from TOMM Trials 1 and 2 and total TOMM scores accurately classified clinical or simulated DID group status. In addition, TOMM Trial 1 demonstrated high specificity (87%) and positive predictive power (94%), as well as moderate sensitivity (78%), negative predictive power (63%), and overall diagnostic power (81%). Despite exposure to DID-specific information, simulators were not able to accurately feign the DID group's TOMM scores, which is inconsistent with the iatrogenic/sociocultural model of DID. The TOMM shows promise as useful in clinical and forensic contexts to detect memory malingering among DID simulators without sacrificing specificity. Accurate distinction between genuine and feigned complex trauma-related symptoms, including dissociative memory, is integral to the accurate diagnosis of traumatized populations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).