B - 45 Assessing MMPI-3 Substantive Scales in Service Members and Veterans with Mild Traumatic Brain Injury (mTBI): Association with Criterion Symptom Measures

Abstract Objective Research on the Minnesota Multiphasic Personality Assessment-3’s (MMPI-3) utility in treatment is scarce, primarily investigating prediction of traumatic symptoms and suicidal risk (Keen et al., 2022; Morris et al., 2024). However, few studies have examined these scales in treatment settings. The current study expands prior research by examining the MMPI-3 substantive scales in a neurocognitive rehabilitation setting from baseline through 12 weeks post treatment. Methods Relative risk ratios evaluated whether Active-duty (n = 22) and Veterans (n = 31) with MMPI-3 scale elevations had an increased likelihood of elevation on common symptom measures (Post-traumatic Checklist-DSM-5 [PCL-5] ≥ 31; Center for Epidemiologic Studies-Depression [CES-D] ≥ 16; Neurobehavioral Symptom Inventory [NSI] ≥ 57) across four timepoints (baseline, one week, four weeks, 12 weeks). Results Those with elevated (T ≥ 65) scores on MMPI-3 substantive scales, particularly for the internalizing and thought dysfunction scales, have increased likelihood of meeting screening criteria on the PCL-5. Numerous scales also predicted CES-D elevation; however, both CES-D and NSI elevations were less pronounced. The NSI was weakly associated with most MMPI-3 substantive scales. Conclusions Veterans and Active-duty personnel with MMPI-3 substantive elevations will likely elevate concurrent measures of symptom severity. Neurocognitive symptoms produce less reliable associations. Longitudinal associations with criterion measures will provide a needed area of expanded validity for the MMPI-3.