Mental health conditions, such as depression and binge eating disorder, may be twice as common among bariatric surgery patients compared to the general U.S. population, with nearly 25 percent suffering from a mood disorder and nearly 20 percent being diagnosed with a binge eating disorder prior to the procedure, a UCLA-led study suggests.
While bariatric surgery is an accepted method of promoting weight loss in severely obese individuals, the prevalence of these conditions among people seeking the procedure and whether they are associated with postoperative outcomes has not been known.
For a study appearing in the Jan. 12 issue of Journal of the American Medical Association, the researchers analyzed 68 journals published between January 1988 and November 2015 to determine the prevalence of mental health conditions among bariatric surgery candidates and recipients and the association between preoperative mental health conditions and health outcomes following bariatric surgery.
The authors defined mental health conditions as depression, anxiety, post-traumatic stress disorder, personality disorders, substance abuse disorders, suicidality or suicidal ideation, and eating disorders, in particular binge eating.
They found that 23 percent of people undergoing bariatric surgery reported a current mood disorder, most commonly depression (19 percent), while 17 percent of those undergoing surgery were diagnosed with an eating disorder.
“Given these rates, it is important for physicians to screen for and treat these conditions in all patients being considered for bariatric surgery,” said lead investigator Dr. Aaron Dawes, a general surgery resident at the David Geffen School of Medicine at UCLA and a Robert Wood Johnson Foundation Clinical Scholar. “At the same time, we found no evidence to suggest that patients with these conditions lose less weight after surgery and some evidence that certain conditions, particularly depression, may actually improve after surgery.
“Although we certainly do not think that surgery should be considered as a treatment for depression, our results suggest that severely obese patients undergoing bariatric surgery may stand to gain mental health benefits in addition to the more-talked-about physical health benefits of the operation,” added Dawes, who is also affiliated with the UCLA Fielding School of Public Health and the Veterans Affairs Greater Los Angeles Healthcare System.
The authors searched for studies on the databases PubMed, Medline on Ovid and Psycinfo, using terms such as “bariatric,” “obesity,” “psychiatric disorders,” and “eating disorders” to identify the 68 publications meeting their criteria for inclusion in the analysis. They found that 59 reported the prevalence of preoperative mental health conditions (65,363 patients) and 27 reported associations between preoperative mental health conditions and postoperative outcomes (50,182 patients).
Neither depression nor binge eating disorder was consistently associated with differences in weight outcomes. Bariatric surgery was, however, consistently associated with postoperative decreases in the prevalence of depression (across seven studies there was an 8 percent to 74 percent decrease) and the severity of depressive symptoms (across six studies there was a 40 percent to 70 percent decrease).
The study has several limitations. First, it was not designed to address causality, so the observation that depression improves after surgery may or may not be directly related to the operation. While surgery may lead to lower rates of depression through weight loss, improvements to self-esteem, and changes to body image, other explanations, such as changes to the body’s biochemistry or selection bias regarding who receives surgery, may be equally likely. Second, the researchers reported on published data, which may not fully represent the practices of bariatric surgeons due to publication bias. Third, the studies they analyzed varied in their scales, threshold, definitions, and, to some extent, their underlying patient populations. Finally, some patients with mental health conditions may have been screened out prior to referral for surgery and may not be represented in the findings.
The authors note, however, that previous reviews have suggested self-esteem, mental image, cognitive function, temperament, support networks, and socioeconomic stability play major roles in determining outcomes after bariatric surgery.
“Future studies would benefit from including these characteristics as well as having clear eligibility criteria, standardized instruments, regular measurement intervals, and transparency with respect to time-specific follow-up rates,” the authors write. “By addressing these methodological issues, future work can help to identify the optimal strategy for evaluating patients’ mental health prior to bariatric surgery.”
The Evidence-based Synthesis Program at the Department of Veterans Affairs funded this study.
Study co-authors are Melinda Maggard-Gibbons of the David Geffen School of Medicine at UCLA, the VA Greater Los Angeles Healthcare System and RAND Corporation; Alicia Maher of the Akasha Center for Integrative Medicine and RAND Corporation; Marika Booth of RAND Corporation; Isomi Miake-Lye of the UCLA Fielding School of Public Health and the VA Greater Los Angeles Healthcare System; Jessica Beroes of the VA Greater Los Angeles Healthcare System; and Paul Shekelle of RAND Corporation and the VA Greater Los Angeles Healthcare System.