Examination of the Reliability and Validity of the Minnesota Multiphasic Personality Inventory-3 (MMPI-3) in a Preoperative Bariatric Surgery Sample

Presurgical psychological assessment of bariatric surgery candidates aims to identify psychosocial risk factors and provide treatment recommendations to facilitate optimal outcomes. Such assessment typically includes psychometric testing and a clinical interview. The Minnesota Multiphasic Personality Inventory (MMPI) has been commonly used as a broadband measure to assess a number of psychosocial domains in bariatric clinics. The newest version of the MMPI, the MMPI-3, was recently released. This study sought to (1) establish whether the MMPI-3 is comparable to the MMPI-2-RF in a sample of patients seeking bariatric surgery, (2) report reliability data for all MMPI-3 scale scores in this sample, and (3) explore associations between commonly used self-report symptom measures and substantive scales of the MMPI-3 to ascertain convergent and discriminant validity patterns. Six hundred and thirty-five presurgical patients completed the MMPI-3 in addition to the Patient Health Questionnaire-9 (PHQ-9), General Anxiety Disorder-7 (GAD-7), Alcohol Use Disorders Identification Test-Consumption (AUDIT-C), and Eating Disorder Examination-Questionnaire (EDE-Q). The majority (79.1%) of the sample was female, 65.5% was white, and 26.6% was Black. Scores on most of the MMPI-3 Emotional/Internalizing Dysfunction scales were meaningfully associated with the PHQ-9, GAD-7, and most EDE-Q subscales (except for Restraint). Meaningful discriminant patterns were observed as well. We conclude that the substantive scales of the MMPI-3 are reliable, comparable to their MMPI-2-RF counterparts, and evidence good convergent validity with extra-test measures assessing depression, anxiety, alcohol use, and eating disorder psychopathology in a preoperative bariatric sample.