IFNG and psychiatric disorder: C-reactive protein (CRP), interleukin 1 (IL-1), interleukin 2 (IL-2) interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interferon-alpha (IFN-α), interferon-gamma (IFN-γ) are cytokines that have been correlated in pathways leading to mental illness and will be briefly discussed in this paper (Levine et al., 1999; Musselman et al., 2001; Lindqvist et al., 2009; Dowlati et al., 2010; Wium-Andersen et al., 2013; Currier, 2015).