| This study examined the ability of various measures to detect malingered posttraumatic stress disorder (PTSD). Multiple measures that varied in methodology---endorsement of unusual symptoms on the Inventory of Problems (IOP), latency times on the Stroop and IOP, performance characteristics regarding symptoms that participants believe might relate to PTSD on the Test of Memory Malingering (TOMM) and IOP, cognitive items on the IOP, and an overall endorsement of PTSD items on the IOP, Dissociative Continuum Scale (DCS) and Detailed Assessment of Posttraumatic Stress (DAPS)---were used. The phenomenon of dissociation was also explored to see if it is more difficult to differentiate PTSD participants with dissociative symptoms from malingerers. It was hypothesized that these multiple measures would be able to discriminate between groups and that dissociation would negatively impact the ability to distinguish between true PTSD, feigned PTSD, and a normal group.; Individuals with PTSD, controls, and simulators were included for participation. To enhance ecological validity, simulators were provided a context trauma, given an external incentive of {dollar}50, and cautioned not to over-exaggerate. In addition, simulators were instructed to spend 30 minutes on the Internet researching about PTSD while being monitored by a computer SPY program, which recorded what websites they searched, in order to gain information about how one goes about faking.; Results indicated that the use of these measures were successfully able to differentiate between groups. Sensitivity, specificity, and positive predictive accuracy all were 100% when discriminating PTSD participants from controls and more importantly, sensitivity of 92.11%, specificity of 90.00%, and positive predictive accuracy of 89.74% was obtained when differentiating between PTSD participants and simulators. The four participants who were misclassified as simulators all obtained high scores on the DCS, which supports the hypothesis that dissociative PTSD participants will be harder to distinguish from malingerers. A high correlation between dissociation and the IOP-PTSD scale and the DAPS Negative Bias scale within the PTSD group is cause for concern. From these results, the best predictors were chosen to create a useable malingering scale for forensic purposes. This scale obtained high classification rates but cross-validation is necessary. |
