A systematic review found that high IL-8, IL-6 and TNF levels might be potential biomarkers for depressive disorders in the elderly.37 A recent exploratory cross-sectional study showed that increased vascular endothelial growth factor (VEGF), IL-7, MCP-1, TNF and IL-1β plasma levels predicted with 95.1% of accuracy the diagnosis of depressive disorder in elderly subjects.38 One study evaluating 119 patients with LoD and 231 patients with EoD showed increased CRP plasma levels in LoD, and this was related with higher social stressors among LoD cases.39 This evidence concerns the gene IL1B and depressive disorder.