Using ROC curves, irisin levels > 85 ng/mL at admission predicted the development of depression at 3 months with the highest sensitivity and specificity [67.6 and 70.7%, respectively; area under the curve (AUC) = 0.74; 95% CI, 0.67–0.81] (Fig. 4). Here, FNDC5 is linked to depressive symptom measurement.