Performance Validity and Symptom Validity Tests: Are They Measuring Different Constructs?

Objective: To evaluate the relationships among performance validity, symptom validity, symptom self-report, and objective cognitive testing. Method: Combat Veterans (N = 338) completed a neurocognitive assessment battery and several self-report symptom measures assessing depression, posttraumatic stress disorder (PTSD) symptoms, sleep quality, pain interference, and neurobehavioral complaints. All participants also completed two performance validity tests (PVTs) and one stand-alone symptom validity test (SVT) along with two embedded SVTs. Results: Results of an exploratory factor analysis revealed a three-factor solution: performance validity, cognitive performance, and symptom report (SVTs loaded on the third factor). Results of t tests demonstrated that participants who failed PVTs displayed significantly more severe symptoms and significantly worse performance on most measures of neurocognitive functioning compared to those who passed. Participants who failed a stand-alone SVT also reported significantly more severe symptomatology on all symptom report measures, but the pattern of cognitive performance differed based on the selected SVT cutoff. Multiple linear regressions revealed that both SVT and PVT failure explained unique variance in symptom report, but only PVT failure significantly predicted cognitive performance. Conclusions: Performance and symptom validity tests measure distinct but related constructs. SVTs and PVTs are significantly related to both cognitive performance and symptom report; however, the relationship between symptom validity and symptom report is strongest. SVTs are also differentially related to cognitive performance and symptom report based on the utilized cutoff score.