Moreover, even subclinical reactivation of the latent virus and increase of the viral DNA level could be sufficient to stimulate secretion of the cytokines (e.g., as IFN-α, IFN-γ, IL-6, IL-12, IL-18, IL-10, and TNF-α) with shown psychotropic (e.g., depression, suicidal thoughts) effects (reviewed in: [43–45]). This evidence concerns the gene IL18 and major depressive disorder.