Arch Clin Neuropsychol. 2023 Oct 8:acad067.205. doi: 10.1093/arclin/acad067.205. Online ahead of print.
OBJECTIVE: Prior research has shown an association between performance validity testing (PVT) and symptom endorsement following mild traumatic brain injury (mTBI) in Veterans. However, no studies have investigated associations between PVT and attribution of symptoms to mTBI. Therefore, we examined relationships between PVT, symptom endorsement, and symptom attribution in Veterans with mTBI history.
METHOD: Participants included treatment-seeking Veterans (n = 37) with remote mTBI histories who were referred to a neuropsychological clinic at a VA Medical Center (91.9% male; 64.9% white). Veterans underwent a neuropsychological assessment and completed a modified version of the Neurobehavioral Symptom Inventory to assess symptom endorsement and symptom attribution (the latter evaluated by having Veterans indicate whether they believed each symptom was caused by their mTBI). Veterans were divided into two subgroups, PVT-Pass (n = 25) and PVT-Fail (n = 12), based on their Test of Memory Malingering performance.
RESULTS: Correlation analyses revealed a significant association between PVT-failure and (a) symptom attribution (r = 0.426, p = 0.009) and (b) symptom endorsement (r = 0.373, p = 0.023). Separate logistic regression analyses controlling for PTSD symptoms showed that symptom attribution (Nagelkerke’s R2 = 0.279) and symptom endorsement (Nagelkerke’s R2 = 0.233) significantly distinguished between PVT groups. According to the Wald criterion, higher attribution of symptoms to mTBI (p = 0.045, OR = 1.21; 95%CI = 1.00-1.45) and greater symptom endorsement (p = 0.049, OR = 1.09; 95%CI = 1.00-1.18) each reliably predicted PVT-failure.
CONCLUSIONS: While both symptom endorsement and symptom attribution were significantly associated with PVT-failure, our preliminary results suggest that symptom attribution is a stronger predictor of PVT-failure. Although future studies are needed to replicate these findings, results highlight the importance of assessing symptom attribution to TBI in this population.