The dangers of failing one or more performance validity tests in individuals claiming mild traumatic brain injury-related postconcussive symptoms.

Evaluating performance validity is important in any neuropsychological assessment, and prior research recommends a threshold for invalid performance of two or more performance validity test (PVT) failures. However, extant findings also indicate that failing a single PVT is associated with significant changes in neuropsychological performance. The current study sought to determine if there is an appreciable difference in neuropsychological testing results between individuals failing different numbers of PVTs. In a sample of veterans with reported histories of mild traumatic brain injury (mTBI; N =178), analyses revealed that individuals failing only one PVT performed significantly worse than individuals failing no PVTs on measures of verbal learning and memory, processing speed, and cognitive flexibility. Additionally, individuals failing one versus two PVTs significantly differed only on delayed free recall scores. The current findings suggest that failure of even one PVT should elicit consideration of performance invalidity, particularly in individuals with histories of mTBI.