CLDN5 and major depressive disorder: Levels of CLDN5 (r = −0.694, *P < 0.01) and CLDN12 (r = −0.578, *P < 0.05) were negatively correlated with the age of onset of depression in the premotor frontal (Fig. 7A) and cerebellum (Supplementary Fig. 3A) respectively while levels of CLDN12 (r = −0.69, *P < 0.01) were negatively correlated with age of onset of schizophrenia in the caudal cingulate cortex (Supplementary Fig. 3A).