Introduction: The extent to which performance validity (PVT) and symptom validity (SVT) tests measure separate constructs is unclear. Prior research using the Minnesota Multiphasic Personality Inventory (MMPI-2 & RF) suggested that PVTs and SVTs are separate but related constructs. However, the relationship between Personality Assessment Inventory (PAI) SVTs and PVTs has not been explored. This study aimed to replicate previous MMPI research using the PAI, exploring the relationship between PVTs and overreporting SVTs across three subsamples, neurodevelopmental (attention deficit-hyperactivity disorder (ADHD)/learning disorder), psychiatric, and mild traumatic brain injury (mTBI).
Methods: Participants included 561 consecutive referrals who completed the Test of Memory Malingering (TOMM) and the PAI. Three subgroups were created based on referral question. The relationship between PAI SVTs and the PVT was evaluated through multiple regression analysis.
Results: The results demonstrated the relationship between PAI symptom overreporting SVTs, including Negative Impression Management (NIM), Malingering Index (MAL), and Cognitive Bias Scale (CBS), and PVTs varied by referral subgroup. Specifically, overreporting on CBS but not NIM and MAL significantly predicted poorer PVT performance in the full sample and the mTBI sample. In contrast, none of the overreporting SVTs significantly predicted PVT performance in the ADHD/learning disorder sample but conversely, all SVTs predicted PVT performance in the psychiatric sample.
Conclusions: The results partially replicated prior research comparing SVTs and PVTs and suggested that constructs measured by SVTs and PVTs vary depending upon population. The results support the necessity of both PVTs and SVTs in clinical neuropsychological practice.
Keywords: Personality assessment Inventory; attention deficit-hyperactivity disorder; mild traumatic brain injury; performance validity test; symptom validity test.