IGF1 and major depressive disorder: Two endocrine markers (third row of Fig. 1) were associated with MDD incidence: low insulin-like growth factor 1 (IGF-1; AOR = 1.34 [1.16, 1.55], FDR = 0.09%) and low testosterone among males (AOR = 1.60 [1.27, 2.00], FDR = 0.07%) but not among females (AOR = 1.01 [0.76, 1.33], FDR = 100%).