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Bariatric surgery substantially reduced depressive symptom scores

Updated: Mar 6, 2023

Patients undergoing bariatric surgery substantially reduced their depressive symptom scores with comparable decreases occurring from six through 24 months after surgery, according to researchers from the Montreal Behavioural Medicine Centre, CIUSSS du Nord-de-l'Île-de-Montréal, Montreal, Quebec, Canada. The authors noted that depression accounts for a large proportion of psychiatric comorbidities patients living with obesity seeking surgical treatment and that these results demonstrate that bariatric surgery results in a large magnitude of change that translates to clinically significant improvements in depressive symptoms, with higher presurgical distress being associated with greater decreases post-surgery.

Previous research has reported that approximately 19% of individuals seeking bariatric surgery have depression and depression after surgery is associated with suboptimal health outcomes, including postsurgical weight-regain and revisional surgeries. However, these studies are limited in their ability for healthcare practitioners to understand the typical change of depressive symptoms at postoperative follow-ups. Therefore, they designed a study to estimate the magnitude depressive symptom scores decreased during these routine follow-up assessment periods.

They conducted a systematic review to estimate the effect bariatric surgery has on changes to depressive symptom scores within the first 24 months following surgery, and to determine whether these effects differed according to the timing of the postoperative follow-up, the depressive symptom tool used, and the type of bariatric procedure.

They identified 46 studies that met inclusion for systematic review and meta-analyses (32,342 individuals) with a mean age of 42 years old, a mean pre-surgical BMI of 47kg/m2 and was comprised of mostly female patients (78%). Most studies were conducted in the US (26.1%), Canada (13.0%) and Australia (8.7%). Most follow-up visits occurred at 12 months (n=32), followed by 6 (n=22) and 24 months (n=13). Depressive symptoms were measured most commonly using the Beck Depression Inventory (BDI; 56.5%), followed by the Hospital Anxiety and Depression Scale (HADS; 30.4%) and Patient Health Questionnaire (PHQ; 13.1%). Most studies performed gastric bypass surgeries (n=35), sleeve gastrectomy (n=21), gastric band (n=12) and duodenal switch (n=5).

All but one of the 46 studies reported improvements to depressive symptom scores following bariatric surgery. Following bariatric surgery, a large effect was observed regarding changes in depressive symptom scores (Hedge's g = 0.804; 95% CI: 0.73–0.88, I2 = 95.7%). Subgroup analysis indicated that decreases in depressive symptom scores following bariatric surgery were comparable across the follow-ups (p=0.999).

Simple meta-regression tests indicated that higher preoperative depressive symptom scores were associated with greater observed effect sizes (p=0.001). Neither preoperative BMI (p=0.288), sex (p=0.445) or age (p=0.108) were associated with the observed effect sizes.

The authors reported a large decrease in depressive symptom scores following bariatric surgery. Decreases in depressive symptom scores at 24 months postoperatively were comparable with 6 and 12 months after surgery. However, they claim that this is the first review to provide a quantitative estimate of the general change to depressive symptom across this postoperative period, as well as how this is impacted by these methodological considerations.

Decreased depressive symptom scores at 6 and 12 months did not differ by the type of bariatric procedure, suggesting similar favourable psychological outcomes irrespective of the type of procedure.

“Future research should consider exploring potential mechanisms that contribute to decreases in depressive symptoms following bariatric surgery” the authors concluded. “Identifying these mechanisms could lead to developing targeted interventions that healthcare providers can offer if surgery recipients experience smaller decreases to depression and/or if depressive symptom scores remain above levels that are indicative of depression. Identifying individuals that continue to live with depression in the postoperative period allows for early intervention, which could help mitigate increasing risk of suboptimal surgical outcomes (e.g., problematic eating, weight regain, and surgical revisions) that undermines the quality of life of individuals who received bariatric surgery.”

The outcomes were reported in the paper, ‘Evolution of depressive symptoms from before to 24 months after bariatric surgery: A systematic review and meta-analysis’, published in Obesity reviews. To access this paper, please click here


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