KITLG and bipolar disorder: There was no significant association between KITLG methylation and childhood adversity in the bipolar disorder patients (β = 0.004, t = 1.039, p = 0.304), whereas there was a significant positive association between childhood adversity and KITLG methylation associated in the healthy individuals (β = 0.012, p = 0.002; model fit: F = 23.11, p < 0.001, R2 = 0.444).