We identified multiple genes and pathways with common or disease specific effects, such as NISCH (P = 9.87 × 10<sup>-3</sup> for BP and 2.49 × 10<sup>-6</sup> for SCZ), ST3GAL3 (P = 1.19 × 10<sup>-2</sup> for ADHD), and KEGG_MAPK_SIGNALING_PATHWAY (P = 1.56 × 10<sup>-3</sup> for ADHD, P = 4.71 × 10<sup>-2</sup> for BP, P = 4.60 × 10<sup>-4</sup> for SCZ).
We found that DNA methylation at birth differentiated ADHD trajectories across multiple genomic locations, including probes annotated to SKI (involved in neural tube development), ZNF544 (previously implicated in ADHD), ST3GAL3 (linked to intellectual disability) and PEX2 (related to perixosomal processes).