This study investigated the relationship between symptom validity scales on the Clinical Assessment of Attention Deficit-Adult (CAT-A) and the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) in the context of Attention-Deficit/Hyperactivity Disorder (ADHD) evaluation. The sample comprised 140 consecutive patients referred for a neuropsychological evaluation of ADHD and were administered the CAT-A and the MMPI-2-RF and a battery of performance-based neurocognitive tests. Results indicated CAT-A/MMPI-2-RF symptom validity concordance of 51% between measures, with 38% concordant valid and 13% concordant invalid responses. Among those with discordance symptom validity results, rates of valid CAT-A/invalid MMPI-2-RF responding (41%) were more common than invalid CAT-A/valid MMPI-2-RF responding (8%). Results also indicated higher levels of ADHD symptoms among invalid responding within the CAT-A, whereas the MMPI-2-RF Cognitive Complaints scale did not differ by CAT-A validity status. Finally, symptom validity scales on both the CAT-A and MMPI-2-RF were largely discordant from neuropsychological test validity status per performance validity tests. Findings highlight the need for symptom validity testing when assessing ADHD and indicate that validity indices on broad personality assessments may assess different constructs than embedded validity indices in ADHD-specific measures.
Keywords: ADHD; neuropsychological assessment; personality assessment; symptom validity.