IL6 and major depressive disorder: The expression of oxidative and inflammatory biomarkers in specific brain areas of depression patients has increased, while H2 has the ability to reduce inflammation by reducing IL-6, IL-1β, IL-12 and TNF-α.[71,72] Repeated inhalation of H2 and oxygen mixture [67%: 33% (V/V)] can significantly reduce the depression-like and anxiety-like behavior induced by acute and chronic stress in mice through tail suspension test, forced swimming test, novel inhibition feeding test and open field test.