Detection of Feigned Posttraumatic Stress Disorder: A Comparison of the MMPI-2 and PAI

Abstract

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and Personality Assessment Inventory (PAI) were compared for detecting feigned posttraumatic stress disorder (PTSD) in a simulation research design. Participants were 85 undergraduates in one of three groups: PTSDs (n = 23), Fakers (n = 31), and Controls (n = 31). As expected, both the MMPI-2 and PAI discriminated PTSDs and Controls, with PTSDs scoring significantly higher on fake-bad validity scales and PTSD-relevant clinical scales. However, only the MMPI-2 discriminated Fakers and PTSDs, with Fakers scoring significantly higher on all MMPI-2 scales considered, but on only one PAI scale. Further, in logistic regression analyses the MMPI-2 demonstrated higher overall correct classification of PTSDs and Fakers than did the PAI. Although the MMPI-2 outperformed the PAI in detecting feigned PTSD, a substantial proportion of Fakers avoided detection by MMPI-2 fake-bad validity scales, suggesting that both tests are vulnerable to feigning of PTSD by motivated respondents with relatively limited coaching.