Concordance of Symptom Validity and Performance Validity Indicators in Neuropsychological Testing: Comparison of the MMPI-2-RF Infrequent Responses Scale and TOMM in Detecting Overstated Pathology in Court-Ordered Forensic, Quasi-Forensic, and Non-Forensic Acquired Brain Injury Outpatients

This study examined the co-occurrence of response invalidity as measured by the Infrequent Responses (F-r) scale of the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2- RF) and the Test of Memory Malingering (TOMM) in 479 participants classified into forensic, quasi-forensic, and acquired brain injury groups. Although participant scores on the MMPI-2- RF F-r scale and TOMM were significantly correlated, concordance of response invalidity in the form of overstated pathology was only 13%. Comparable rates of potential feigning were found across groups on the MMPI-2-RF, but a larger percentage of participants in the forensic group obtained scores suggestive of possible feigning on both Trial 2 and the Retention Trial of the TOMM. Multivariate analyses also revealed that participants in the forensic group scored significantly below the quasi-forensic and brain injury groups on both Trial 2 and the Retention Trial of the TOMM. No significant mean score differences on the MMPI-2-RF F-r scale were found among groups. Results have meaningful implications for neuropsychological practitioners, suggesting limited concordance of symptom and performance validity as assessed by these instruments and highlighting potential concerns of performance invalidity associated with possible feigning in individuals referred for outpatient neuropsychological testing secondary to court order