Title: Are depression, anxiety, body mass index, and types of surgery predictive of weight loss and psychological outcomes after bariatric surgery?
Description: Background: The primary goal of bariatric surgery is to not only lose weight but also resolve comorbidities and improve quality of life. It is crucial to identify predictors of surgical outcomes. The current study investigates pre-surgical depression, pre-surgical anxiety, and demographic factors (age, gender, education, race, and baseline body mass index) as predictors of post-surgical outcomes as well as examines difference in the effect of laparoscopic Roux-en-Y gastric bypass versus laparoscopic adjustable gastric banding on post-surgical surgical outcomes. Methods: The study is a retrospective one-group pre-test-post-test design study that examined 88 (Females = 81, Males = 7) bariatric surgery participants at St. Luke's-Roosevelt Hospital. Data collected at baseline (three weeks prior to surgery) and 1 year post-surgery from participants administered the Zung Self-rating Depression Scale, the Liebowitz Social Anxiety Scale - Self-Report Version, and Quality of Life - Lite Scale were analyzed.

Participants underwent either laparoscopic Roux-en-Y gastric bypass surgery or laparoscopic adjustable gastric banding surgery. Results: Age (F = 4.0, p = 0.05) and baseline body mass index (F = 5.8, p = 0.02) were significant predictors of % excess weight loss. Age (F = 4.2, p = 0.04) and baseline body mass index (F = 33.6, p < 0.001) were significant predictors of absolute weight loss (kg). Baseline body mass index (F = 4.2, p = 0.046) was also a significant predictor of total quality of life. The effect of laparoscopic Roux-en-Y gastric bypass versus laparoscopic adjustable gastric banding differed in changes in pre- to post-surgical total quality of life (F = 12.5, p = 0.001), % weight loss (F = 126.3, p < 0.001), % excess weight loss (F = 124.8, p < 0.001), and absolute weight loss (F = 87.7, p < 0.001). Baseline depression and baseline anxiety were not predictive of weight loss (% excess weight loss, % weight loss, or absolute weight loss), but baseline anxiety was predictive of post-surgical depression (F = 13.0, p = 0.001), post-surgical anxiety (F = 43.8, p < 0.001), and post-surgical total quality of life (F = 8.6, p = 0.005).

Conclusion: The data show that younger age and lower baseline body mass index are positive predictors of weight loss, lower baseline body mass index and lower baseline anxiety are positive predictors of quality of life, and lower baseline anxiety is a positive predictor of post-surgical depression and anxiety. The data also show that baseline depression and baseline anxiety are not predictors of post-surgical weight loss. Hence, the data suggest that younger adults have a bigger chance to succeed at greater weight loss after surgery. In addition, treating baseline anxiety disorder might result in better quality of life after surgery. Interventions that are effective in lowering baseline body mass index might help with greater post-surgical weight loss and better post-surgical quality of life. Those with better scores on the baseline depression and anxiety assessment do not necessarily have greater weight loss after surgery, so denial of surgery to those with psychopathology should be further examined. Long-term follow-up is necessary.