Serum HMGB1 and sRAGE concentrations were measured by enzyme‐linked immunosorbent assay in a group of patients with severe major depressive disorder (MDD) (11 males and 14 females) who required treatment with electroconvulsive therapy (ECT), and also in a group of 25 age‐ and gender‐matched healthy subjects. This evidence concerns the gene HMGB1 and major depressive disorder.