ZBTB16 and major depressive disorder: Also of interest, the second most strongly associated CpG in the co-methylated module was annotated to ZBTB16, a protein coding gene involved in the cell cycle progression that has been linked to various psychiatric outcomes bridging the internalizing and externalizing divide, such as conduct disorder symptoms (Sonuga-Barke et al., 2008), ADHD (Zayats et al., 2015), and major depressive disorder (Spijker et al., 2010).