In the majority of studies regarding the TNF-α system and psychiatric disorders or psychopharmacological treatment, it would have also been useful to determine the concentration of anti-inflammatory cytokines such as IL-10 or IL-4 to assess the degree of imbalance between the inflammatory and anti-inflammatory arms of the immune system, but this issue has not been addressed systematically during psychoimmunological research. Here, IL4 is linked to psychiatric disorder.