SLC6A4 and psychiatric disorder: The mRNA expression of five genes, namely, Il-1β, Crh,Bdnf, slc6a4, and Aif1, were measured in this study; these 5 genes are related to neuroinflammation, the HPA axis, neuroplasticity, serotonin uptake, and microglia status, respectively, and all of them are closely associated with the pathogenic mechanisms of mental illness (Laryea et al., 2012; Jones and Thomsen, 2013; Andero et al., 2014).