Objective: This study examined concordance between symptom and performance validity among clinically-referred patients undergoing neuropsychological evaluation for Attention-Deficit/Hyperactivity Disorder (ADHD).
Method: Data from 203 patients who completed the WAIS-IV Working Memory Index, the Clinical Assessment of Attention Deficit-Adult (CAT-A), and ≥4 criterion performance validity tests (PVTs) were analyzed.
Results: Symptom and performance validity were concordant in 76% of cases, with the majority being valid performance. Of the remaining 24% of cases with divergent validity findings, patients were more likely to exhibit symptom invalidity (15%) than performance invalidity (9%). Patients demonstrating symptom invalidity endorsed significantly more ADHD symptoms than those with credible symptom reporting (ηp2 = .06-.15), but comparable working memory test performance, whereas patients with performance invalidity had significantly worse working memory performance than those with valid PVT performance (ηp2 = .18).
Conclusion: Symptom and performance invalidity represent dissociable constructs in patients undergoing neuropsychological evaluation of ADHD and should be evaluated independently.
Keywords: ADHD; assessment; malingering; neuropsychological functioning.