Symptom validity indices in the Posttraumatic Stress Disorder Checklist for DSM-5.

Abstract

The use of symptom validity tests (SVTs) is standard practice in psychodiagnostic assessments. Embedded measures are indices within self-report measures. To date, no embedded SVTs have been identified in the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5). This research aimed to develop and validate PCL-5 SVTs in two samples of veterans. Participants completed one of two prospective research studies that included cognitive and psychological tests. Participants in Study 1 were veterans (N = 464) who served following the September 11, 2001, terrorist attacks; participants in Study 2 were veterans or service members (N = 338) who had been deployed to Iraq and/or Afghanistan. Both studies included the PCL-5 and the Structured Inventory of Malingered Symptomatology (SIMS), the latter of which served as the criterion for identifying PCL-5 SVTs. For Study 1, two separate SVTs were developed: the PCL-5 Symptom Severity scale (PSS), based on the PCL-5 total score, and the PCL-5 Rare Items scale (PRI), based on PCL-5 items infrequently endorsed at the highest item ratings. At the most conservative SIMS cutoff score, the PSS achieved excellent discrimination for both the Study 1, AUC = .840, and Study 2 samples, AUC = .858, with specific cutoff scores of ≥ 51 and ≥ 56 maximizing sensitivity while maintaining a specificity of .90. The PRI achieved good discrimination, AUCs = .760 and.726, respectively, with a cutoff score of 2 or higher indicated by both studies. The results of these two studies provide provisional support for these two embedded SVTs in the PCL-5.