In addition, higher transferrin levels, which are indicative of lower iron status, were associated with increased risk of gender identity disorders (OR: 1.53; 95%CI: 1.17, 2.00; P < 0.005) as well as decreased risk of somatoform disorder (OR: 0.87; 95%CI: 0.78, 0.98; P = 0.02) and psychogenic disorder (OR: 0.68; 95%CI: 0.59, 0.77; P < 0.001) (Figure 4). This evidence concerns the gene TF and psychiatric disorder.