The association between body mass index and treatment outcomes in major depressive disorder: a CAN-BIND-1 study

Being overweight is commonly observed in patients with major depressive disorder (MDD). However, the relationship between body weight and treatment outcomes in MDD is less clear. In this context, we examined the association between BMI and treatment outcomes in patients treated with escitalopram with and without adjunctive aripiprazole. We tested this association using data from the Canadian Biomarker Integration Network in Depression-1 (CAN-BIND-1). The sample consisted of 180 participants who were treated with escitalopram for 8 weeks, followed by 8 more weeks of treatment with escitalopram alone (for responders) or escitalopram plus aripiprazole (for non-responders). Punishment/reward sensitivity and physical activity were also explored. Logistic regression analysis was used to examine the association between BMI, being overweight, and treatment response or remission after 8 or 16 weeks of treatment. BMI, being overweight, physical activity, behavioral inhibition, and behavioral activation were not associated with treatment outcomes. We also reviewed the recent literature on BMI, obesity, and antidepressant treatment outcomes, which showed mixed findings. Our results, which showed a lack of association between BMI and treatment outcomes, add to this complexity of the relationship between body weight and treatment outcomes in MDD. Larger studies with more diverse samples are needed to validate these results.