Confirmatory factor analysis of the Beck Depression Inventory-II in bariatric surgery candidates

Screening for depression is an integral part of psychological evaluations conducted prior to bariatric surgery. The Beck Depression Inventory-II (BDI-II) is the most commonly used measure of depression in these treatment evaluations. The reliability and validity of the BDI-II has not yet been evaluated within bariatric surgery-seeking samples, evidencing a significant gap in the present literature. The purpose of the present study is to evaluate the structural validity of the BDI-II and to examine the reliability and convergent and criterion validity of this instrument within a bariatric surgery-seeking sample. The study population consisted of 505 ethnically diverse bariatric surgery candidates presenting for presurgical psychological evaluations in a midwestern urban academic medical center. Confirmatory factor analytic results indicated that a 3-factor model consisting of affective, cognitive, and somatic factors was the best fitting model of depression within this sample. Internal consistency reliability was satisfactory for each subscale, ranging from .72 to .82. Moderate to large correlations were observed between each BDI-II subscale and a measure of depression previously validated with bariatric surgery candidates indicating adequate convergent validity. On the basis of clinical interview, 14% of the sample was diagnosed with current major depression. Significant mean differences were observed between depressed and nondepressed patients with respect to each BDI-II subscale score, demonstrating criterion-related validity. The BDI-II is a reliable and valid measure of depression for bariatric surgery candidates. Understanding the factor structure of the BDI-II can be useful for planning potential presurgical psychological interventions.