The long-term effect of bariatric surgery on depression and anxiety.

BACKGROUND: No previous review has comprehensively assessed long-term changes in anxiety and depressive symptoms in bariatric surgery patients. This systematic review assessed the effects of bariatric surgery on long-term reductions (≥ 24 months) in anxiety and depressive symptom severity in morbidly obese (≥ 35 BMI kg/m2) participants. Short term effects (< 24 months) are briefly reviewed for context. METHODS: PsychINFO, Google Scholar and PubMed databases were systematically searched for prospective cohort studies published from inception to 14 June 2018 that evaluated long-term (≥ 24 months) changes in anxiety and depressive symptom severity in bariatric surgery patients with a BMI ≥ 35 kg/m2 using a combination of the following search terms: bariatric surgery (and surgical approaches included under this term), obesity, depression, depressive disorder, anxiety, anxious, psychiatric disorders, mood disorders. RESULTS: We reviewed 2058 articles for eligibility; 14 prospective studies were included in the systematic review. 13 studies (93%) reported significant reductions in depressive symptom severity 2-3 years after bariatric surgery. However, all studies recorded statistically significant reductions in depressive symptoms at the conclusion of the study. Similarly, there were reductions in overall anxiety symptom severity at ≥ 24 months follow-up (k = 8 studies, n = 1590 pooled). Pre-operative anxiety or depression scores did not predict outcomes of post-operative BMI. Similarly, post-surgery weight loss did not predict changes in anxiety symptoms. LIMITATIONS: Very few studies assessed anxiety or depression as a primary outcome. Therefore, we cannot suggest bariatric surgery as a stand-alone therapeutic tool for anxiety and depression based on our findings. CONCLUSION: Currently available evidence suggests that bariatric surgery is associated with long-term reductions in anxiety and depressive symptoms. This supports existing literature showing that metabolic treatments may be a viable therapeutic intervention for mood disorders.