Exploring the sensitivity of the Personality Assessment Inventory symptom validity tests in detecting response bias in a mixed neuropsychological outpatient sample

OBJECTIVE: Few studies have evaluated the symptom validity tests (SVTs) within the Personality Assessment Inventory (PAI) in a neuropsychological assessment context. Accordingly, the present study explored the accuracy of PAI SVTs in identifying exaggerated cognitive dysfunction in a mixed sample of outpatients referred for neuropsychological assessment. METHOD: Participants who failed two or more Performance Validity Tests (PVTs) were classified as having exaggerated cognitive dysfunction (n = 49). Their responses on PAI SVTs were compared to examinees who did not fail PVTs (n = 257). RESULTS: Multivariate analysis of variance indicated the Negative Impression Management (NIM) scale most strongly discriminated between those with exaggerated cognitive dysfunction from honest responders (Cohen's d = .58). Nonetheless, its classification accuracy was low (area under the curve [AUC] = .65). A k-means cluster analysis and a subsequent multinomial logistic regression indicated evidence for two distinct groups of exaggerators. In particular, one group seemed to exaggerate symptoms, whereas another presented in a defensive manner, implying that individuals with positive and NIM biases on the PAI were apt to display invalid performance on PVTs. CONCLUSIONS: Findings indicated that exaggerated cognitive dysfunction tends to be present when NIM is very high and that evidence exists for a defensive response style on the PAI in the context of PVT failure.