The Influence of Depression on Bariatric Surgical Outcomes

Abstract

Over 40% of adults in the United States are classified as obese. American adults with severe obesity experience symptoms of depression at double the rate of normal-weight people. Bariatric surgery (BS) is a safe and effective treatment for severe obesity that results in long-term weight loss. The estimated 19% of BS patients who suffer from depression after surgery exhibit a lower-than-average percentage of excess weight loss (%EWL) over time. These BS patients also do not attend follow-up appointments, which makes treating their symptoms of depression difficult for healthcare providers. This study examined the relationship between depression, %EWL, and follow-up attendance to ascertain if depression influenced whether BS patients achieved their %EWL goal as well as attended their 12- and 24-month follow-up appointments. Non-identifiable data in 212 electronic medical records were examined of adults aged 18-64 who had their first BS from 2012 to 2020 at an academic medical center. The BS patients were sorted into two depression status groups per their pre-surgical BDI-II score for statistical analysis. This categorization resulted in 44% of the BS patients in the with depression group (mean BDI-II score 21 ± 9 points) and 56% in the without depression group (mean BDI-II score 8 ± 5 points). A repeated measures mixed model found no statistically significant decrease in %EWL between or within the depression status groups at 12- and 24-months post-BS – even when controlling for patient characteristics (age, sex, race, insurance type, marital status, education level, employment status, and antidepressant medication). A generalized linear mixed model found a statistically significant decrease in the follow-up attendance from 12 to 24 months within both depression status groups (with depression p < .001; without depression p = .003) when controlling for the same patient characteristics except race. However, when controlling for patient characteristics, no statistically significant decrease in follow-up attendance was found between the depression status groups at 12 months (p = .887) or 24 months (p = .229). The results of this study were inconclusive regarding whether depression influenced BS outcomes since BS patients were only assessed for symptoms of depression before surgery and not at each follow-up appointment after surgery. A prospective study with a mixed-methods design is needed to determine if surgical outcomes are associated with depression and why BS patients do not attend follow-up appointments. Follow-up attendance is essential for treating BS patients over time, so they can successfully achieve and maintain their weight loss goals.