Stratified performance on the Test of Memory Malingering (TOMM) is associated with differential responding on the Personality Assessment Inventory (PAI)

Introduction: This study evaluated symptom endorsement patterns in participants at various stratified performance levels on the Test of Memory Malingering (TOMM). It was hypothesized that the lowest stratum (chance performance and below) would have the most pathological (i.e., elevated item endorsement) responding on the Personality Assessment Inventory (PAI) validity and clinical scales. This study was primarily a replication of previous work with emphasis on the PAI scales and consideration of varying degrees of performance on TOMM Trial 2. Methods: Participants were 760 (54% female, 85.4% Caucasian, mean age = 42.01 (SD = 15.89), mean education = 13.55 (SD = 2.35)) consecutively referred neuropsychological outpatients who completed the TOMM and PAI. Participants were placed in one of 5 stratified TOMM Trial 2 performance level groups (High Pass, Low Pass, High Fail, Low Fail, and Chance). No significant differences were found between the demographic variables except for referral source, which was overrepresented in the Chance group relative to the other groups. Results: Due to the highly skewed nature of TOMM Trial 2, Spearman rank order correlations were calculated for the 5 stratified levels of TOMM performance and all the main PAI scales. The NIM, SOM, DEP, ANX, SCZ and SUI scales had significant correlations, so a series of One-way ANOVAs were calculated to examine these scales at different TOMM stratified performance levels. Results indicated that the Chance group had the highest level of responding on all scales, with NIM, SOM, DEP, SCZ and SUI having mean elevations above the clinical cutoff (T = 70). Conclusions: Results were consistent with previous pass-fail PVT research, but extended earlier research to provide evidence that Chance performance group had more pathological PAI responding. The results provide preliminary evidence to support the notion that patients who fail PVTs at different levels do not have the same characteristics.