for National Geographic News
Childhood abuse can permanently alter the way a key stress-fighting gene works, leaving victims more vulnerable to stressful events throughout their lives, new research reveals.
Scientists compared the brains of suicide victims who had been abused as children with the brains of non-abused suicide victims and people who died of other causes.
"It seems that we see in the genome the mark of childhood abuse," said study co-author Moshe Szyf of Montreal's McGill University. The finding was published this week in the journal Nature Neuroscience.
Leaving a Mark
The genes we inherit are marked with chemicals that help determine how they will perform their functions.
In this case, the abuse victims' underlying DNA was not changed. Instead, a particular gene's expression was dampened, causing the brain to produce fewer calming hormones.
The idea that the environment can have this sort of impact is key in the developing field of epigenetics, the study of how gene expression changes without altering DNA.
"It's provocative, because we're not talking about drugs or toxins [changing gene expression] but simply the social environment," Szyf said.
Kerry Ressler of the Howard Hughes Medical Institute and Emory University in Atlanta, said: "It's been known that child abuse is one of the highest risk factors for all sorts of adult psychiatric disorders.
"It's also known that all those disorders have a genetic component to them," he added.
"Now these types of studies are kind of getting at how [child abuse and genetic components] interact with one another."
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