Patients with depression were reported to exhibit an activation of the inflammatory response as shown by increased levels of proinflammatory cytokines (e.g. interleukin-1β (IL-1β), IL-6, tumor necrosis factor-a (TNF-a), interferon-γ (IFN-γ)) and altered secretion of anti-inflammatory cytokines (e.g. interleukin-4 (IL-4) and IL-10), as well as increased concentrations of acute-phase proteins in the peripheral [1–5]. Here, IL4 is linked to depressive disorder.