The Relationship of Presurgical Personality Assessment Inventory Scales to BMI Following Bariatric Surgery

Objective: Notwithstanding the efficacy of bariatric surgery in reducing the negative sequelae of obesity, psychological factors may play a significant role in long-term weight maintenance following surgery. Previous research on these factors has shown mixed outcomes, indicating the need for further study in samples undergoing bariatric surgery. Method: This study evaluated archival data for 194 patients from a single-payer system for a 60-month period following bariatric surgery to examine how presurgical scores on the Personality Assessment Inventory predict body mass index (BMI) over time. Follow-up data was available on 97% of these patients at 12 months and 62% of these patients at 60 months. Hierarchical linear modeling was used to predict BMI based on demographic and psychopathology factors using linear and nonlinear coefficients while controlling for initial BMI. Results: Results showed that Personality Assessment Inventory scales assessing anxiety-related disorders, mania, and alcohol problems showed a relationship to BMI outcomes over time. Contrary to expectations, moderate elevations on anxiety-related disorders and mania were associated with a greater initial linear trend for BMI decrease, with a steeper slope for weight regain after approximately 3 years. Patients endorsing any scores above the minimum on the alcohol problems scale showed poorer BMI outcomes. Conclusions: This study extends previous research on psychological factors and weight outcomes over time among patients undergoing bariatric surgery. In contrast to a focus on clinical elevations when using broadband measures of psychopathology, these results suggest a more nuanced pattern of weight loss and subsequent regain associated with certain subclinical elevations.