Objective: Although reported to be effective as a performance validity test (PVT) in TBI and ADHD, little is known about the ability of the CPT-II to model performance validity in psychiatric patients. Also, while repeat CPT-II administrations have been shown to enhance its diagnostic accuracy in ADHD evaluations, the effect of such strategic redundancy on validity assessment is largely unknown. Method: CPT-II subtests previously identified as embedded PVTs (ePVTs) were systematically tested in a sample of 30 patients with a variety of psychiatric conditions but without credible evidence of neuropsychological impairment. Neurocognitive profiles were classified as valid (n = 18) and invalid (n = 12) using a composite measure based on 20 independent PVTs. The CPT-II was administered twice, at the beginning and at the end of the testing session. Results: Significant improvement in signal detection properties was observed from Time 1 to Time 2 for Commission T ≥ 60, Perseveration T ≥ 70, Variability T ≥ 60 and the combination of Commission T ≥ 60 and Variability T ≥ 60. No difference was found for Omission T ≥ 80 and Hit RT T ≥ 60. Negligible loss in sensitivity was noted on Hit RT SE T ≥ 90. Conclusion(s): Results suggest that the ePVTs in the CPT-II developed in TBI and ADHD samples generalize to other clinical populations. Furthermore, invalid neuropsychological profiles are common in psychiatric patients (40% of the current sample). Finally, repeating the CPT-II or administering it later during the day tends to improve its signal detection properties as a PVT.