How Trauma Causes Epigenetic Changes Epigenetic modifications occur through three primary mechanisms: Trauma adds or removes chemical tags (methyl groups) to DNA, affecting how genes are turned “on” or “off.” For example, studies show that childhood trauma increases methylation of the NR3C1 gene, which regulates the stress hormone cortisol. This results in an overactive stress response, making survivors more… Read More How Trauma Causes Epigenetic Changes