Childhood trauma can leave scars on DNA, Harvard-UBC study finds

October 4, 2018

Children who are abused can be left with physical, "molecular scars" on their DNA that last well into adulthood, according to a new study from Harvard University and the University of British Columbia.

The findings could one day impact disease research as well as criminal investigations, though more work needs to be done before experts know how the "tagging" — known as DNA methylation — affects a victim's long-term mental and physical health.

But Nicole Gladish, a PhD candidate at UBC and co-author of the study, said the research is a promising development for researchers looking to better understand the link.

"It's a really good first step," she said.

Pilot study

A team of UBC researchers looked at chemical tags on the DNA of 34 adult men for the study, published in Translational Psychiatry on Tuesday.

Gladish researchers were looking for methylation in the mens' sperm.

If genes are lightbulbs, Gladish explained, methylation is a "dimmer switch" that affects how cells are turned on or off.

Seventeen of the participants had reported being physically attacked as children, with two saying they'd been sexually abused. 

Gladish said there was a "striking" difference in tagging between those who'd been abused and those who had not.

"Typically, most studies see [percentage] differences about five per cent to 10 per cent ... some of these differences were very large in the 20 per cent range up to 29 per cent," said Gladish, who analyzed much of the data for the study.

"Essentially, [it means] these little tiny tags on the DNA are kind of put into place at the time of abuse and are just present and persist throughout the life's course."

Read more: Childhood trauma can leave scars on DNA, Harvard-UBC study finds