Body mass index is associated with the antidepressant effects of intravenous ketamine in patients with depression.

Patients with depression and a higher baseline body mass index (BMI) experienced greater reductions in depressive symptoms after six intravenous ketamine infusions compared with those with a lower baseline BMI. In a study of 135 patients (103 with major depressive disorder, 32 with bipolar depression), those with a lower BMI (under 26) showed a significantly higher response rate after the first infusion (40.3% vs. 23.6%), but this difference disappeared by the sixth infusion. The overall change in depression scores over time differed significantly between the groups, with the higher-BMI group showing greater improvement. The findings are from an exploratory, post-hoc analysis of an open-label, single-arm trial.

Study at a glance

Abstract

We aimed to explore the correlation between baseline body mass index (BMI) and the antidepressant properties of intravenous ketamine in patients with depression. We divided 135 patients diagnosed with either major depressive disorder (n=103) or bipolar depression (n=32) into lower and higher BMI groups based on their baseline BMI. Patients with a lower BMI (BMI0.05). The linear mixed models with covariates indicated a significant group-by-time interaction in the MADRS scores (F 13, 1729=3.0, P0.05). Our exploratory, post-hoc analysis of an open-label, single-arm study suggests that patients with depression and a higher baseline BMI may experience greater reductions in depressive symptoms compared with those with a lower baseline BMI after receiving six ketamine infusions.