The mitochondrial lymphocyte count indices of CD3+ (t = 3.535, p = 0.001), CD3+CD4+ (t = 2.953, p = 0.004), and CD3+CD8+ (t = 3.498, p = 0.001) T lymphocytes in the schizophrenia group were lower compared to the control group. This evidence concerns the gene CD8A and schizophrenia.