Feigning combat-related posttraumatic stress disorder on the personality assessment inventory

This study examined whether individuals who were instructed on the Diagnost ic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American P sychiatric Association, 1994) criteria for posttraumatic stress disorder (P TSD) could feign PTSD on the Personality Assessment Inventory (PAI; Morey, 1991). The study also investigated whether PAI indexes of symptom exaggerat ion, the Negative Impression Management (NIM) scale and the Malingering ind ex, could identify individuals feigning PTSD. The diagnostic rule for PTSD (Morey, 1991, 1996) was applied to the profiles of a group of 23 veterans w ith combat-related PTSD and 23 male undergraduates instructed to malinger P TSD. Seventy percent of the student malingerers produced profiles that rece ived diagnostic consideration for PTSD. The NIM cutting score (greater than or equal to 8) was highly effective in detecting simulation of PTSD but re sulted in the misclassification of a large number of true PTSD cases. There were no significant differences in the overall efficiency of the test with various validity criteria. We discuss the implications of these findings f or the use of the PAI in the diagnosis of combat-related PTSD.