The results indicated that the expression of three genes [NADH dehydrogenase complex: Ndufs4 (F1,8 = 1.139, P = 0.025), ATP synthase: Atp5e (F1,8 = 2.062, P = 0.019), and cytochrome C oxidase: Cox5b (F1,8 = 2.284, P = 0.004), Figure 6B] was downregulated in MDD mice, consistent with the RNA-seq results. This evidence concerns the gene COX5B and major depressive disorder.