Predicting Outcome of Gastric Bypass Surgery Utilizing Personality Scale Elevations, Psychosocial Factors, and Diagnostic Group Membership

Researchers have traditionally relied upon various presurgical biopsychosocial measures to predict weight loss success following bariatric surgery. The present study proposed a diagnostic grouping system to predict postsurgical outcome. It was hypothesized that psychosocial and Minnesota Multiphasic Personality Inventory (MMPI)/Millon Clinical Multiaxial Inventory (MCMI) psychometric variables could be used to identify gastric bypass surgery candidates requiring additional preoperative and postoperative services. Of 143 candidates for surgical treatment of morbid obesity, 120 women and 23 men underwent psychological evaluation prior to approval for gastric bypass. Each was placed into one of four diagnostic groups based upon results of personality measures and a preoperative semistructured interview. Results support the K scale of the MMPI-2 as a significant predictor of postsurgical outcome; MCMI scores on the schizoid, schizotypal, and compulsive scales appeared to be better overall predictors of outcome.