This research also includes parameters supporting the inflammatory hypothesis of depression [11]: myeloperoxidase, inducible nitric oxide synthase, pro- and anti-inflammatory cytokines, and the phenomenon of oxidative stress may lead to a deficit in serotonin and melatonin via the kynurenine pathway, which is considered as one of the main reasons for depression. The gene discussed is NOS2; the disease is depressive symptom measurement.