The potential for faking on the Mississippi Scale for Combat-Related PTSD.

The Mississippi Scale for Combat-Related PTSD is widely used in the assessment of post-traumatic stress disorder (PTSD). The high face-validity of the scale may make it vulnerable to faking, however. The present study found that the scores of individuals instructed to respond "as if" they had PTSD did not differ from the scores of veterans with PTSD. Furthermore, although veterans who were diagnosed as having PTSD were found to have significantly higher Mississippi Scale scores than those who did not meet diagnostic criteria for PTSD, the mean score for all groups (veteran and non-veteran) exceeded the originally recommended diagnostic cut-off score of 107. A cutoff score of 121 was found to best differentiate veterans with PTSD from veterans who did not meet diagnostic criteria for the diagnosis, with high sensitivity but relatively low specificity.