A 6-week double-blind placebo-controlled randomized clinical trial considering 100 inpatients with first-episode drug-naive schizophrenia, all of whose IDO levels and the levels of six other inflammatory cytokines IL-1β, IL-6, TNF-α IL-17, IL-4, and IFN-γ were higher than the healthy subjects, all individuals in this study group were administered celecoxib (a COX- 2 inhibitor) or placebo combined with risperidone. This evidence concerns the gene IFNG and schizophrenia.