KITLG and major depressive disorder: CTQ, salivary cortisol and mononuclear cell gene expression levels of the three PBMC transcripts NR3C1, FKBP5 and KITLG, did not correlate with age nor showed significant mean differences between males and females among the entire sample, nor showed significant differences between the 35 SY subjects with MDD and those without MDD, nor between the 56 SY with any comorbid psychiatric diagnoses and those without such diagnoses.