Electroconvulsive therapy and adiposity-related parameters in treatment-resistant depressed patients

Obesity is often accompanied by major depressive disorder (MDD), and vice versa. Latest research findings suggest the body mass index (BMI) to play a role in antidepressant treatment response in general. Our study aims to examine whether adiposity-related parameters such as BMI, glucose homeostasis, or serum lipids are associated with remission to electroconvulsive therapy (ECT). A pilot study (PS, n = 9) and a glucose study (GS, n = 29) were conducted. Blood was withdrawn directly before and 15 min (GS) as well as 1 h (PS) after the first ECT and directly before the last one (usually an ECT series comprised up to twelve sessions). BMI was associated with remission in the PS (remitters: M = 28, SD = 2.5; non-remitters: M = 22, SD = 2.08; t(7) = 3.325, p < 0.001, d = 0.24) but not in the GS or when pooled together. Glucose and insulin levels increased significantly after a single ECT session (GS: glucose: F (2,25.66) = 39.04, p < 0.001; insulin: PS: F (2,83) = 25.8, p < 0.001; GS: F (2,25.87) = 3.97, p < 0.05) but no chronic effect was detectable. Serum lipids were neither significantly altered after a single ECT session nor during a whole course of ECT. There was no difference between remitters and non-remitters in insulin, glucose, or serum lipid levels. Our study is lacking the differentiation between abdominal and peripheral fat distribution, and the sample size is small. Unexpectedly, BMI, glucose homeostasis, and lipid serum levels did not differ in patients remitting during ECT. In contrast to recently published studies, we cannot confirm the hypothesis that BMI may have an impact on ECT response.