Is Obesity A Determinant Of Success With Pharmacological Treatment For Depression? A Systematic Review, Meta-Analysis And Meta-Regression.

Background: The bidirectional association between Major Depressive Disorder (MDD) and obesity suggests that body mass index (BMI) at the baseline could influence remission rates (RR) with pharmacological treatment. We evaluated the influence of baseline BMI on the chances of remission among patients with MDD administered antidepressants.

Methods: Based on the guidelines of the PRISMA statement, we conducted a systematic review on PubMed, Cochrane and Embase databases with subsequent meta-analysis and meta-regression. We included only randomized controlled trials evaluating the efficacy of antidepressants of different classes (monotherapy and combined therapies) that evidenced baseline BMI assessment. We created a model to describe the linear relationship between baseline BMI and RR.

Results: Our systematic review yielded 70 studies with a total of 9,779 patients in the active group and 7,136 patients in the placebo group. In placebo controlled studies, BMI influenced the RR of patients randomized to active treatment. The RR for antidepressants in monotherapy was higher in normal weight to overweight patients rather than obese patients (33% vs 12%, respectively). Also in monotherapy, the RR is higher when the study is conducted on patients with a lower baseline BMI (p=0.029). For combined therapies, the pooled RR was higher in obese patients rather than in normal weight to overweight patients (75% vs 17%, respectively).

Limitations: BMI provides no information about body composition and obesity can be related to several potential confounders that potentially influence RR.

Conclusion: The RR with antidepressant therapy seems to be associated with baseline BMI in patients with MDD, although this simple variable was insufficiently explored so far.