Why Does Early Adversity Have Such an Enduring Impact?

To explain the well-known impact of early trauma on later development, investigators examined blood DNA methylation (DNAm) patterns at birth and age 7 years from 971 children in a larger study who underwent comprehensive prospective reassessment five times during childhood. Of the sample, 67% (650) were exposed to adversity, which comprised physical, sexual, or emotional abuse; maternal psychopathology; single-adult household; family instability; poverty; or neighborhood disadvantage.

At age 7, differential methylation — that is, not present at birth and occurring after adversity — was identified at 38 sites. Most DNAm was related to adversity before age 3 years. Other models using total adversity, adversity close to the time of measurement,…