Abuse in early childhood can dramatically alter the way the brain copes with stress in adulthood, research shows.

Children abused during their formative years can undergo a change in the structure of their brains, which inhibits the expression of a stress hormone-related gene (NR3C1).

This would make such children less able to cope with stress, according to the Canadian study, which examined the brains of 12 people with a history of child abuse who had taken their own lives.

The brain samples were compared with those of two other groups: people who had committed suicide but had no history of abuse, and those who had died of natural causes.

"They found significant differences in stress-related hormone receptors in those who had committed suicide and had been abused," said Queensland University of Technology (QUT) Professor Ross Young, commenting on the findings.

"They also found evidence that parts of the NR3C1 gene may be switched off by this abuse, leading to an abnormal stress response in adulthood."

The change in the functioning of the gene occurred in the hippocampus, the part of the brain largely responsible for memory function.

The study showed how the reduced expression of the gene led to an increase in hypothalamic-pituitary-adrenal (HPA) response to stressful situations.

Such heightened HPA responses have previously been linked to an increased risk of suicide, mood disorders and also schizophrenia.

Early childhood experience has been shown to cause long-term genetic changes in the stress response pathway in rats, but this is the first evidence that the same thing happens in humans.

Prof Young, the executive director of the Institute of Health and Biomedical Innovation at QUT, said the findings reinforced the importance of child abuse prevention.

"We also need to ensure that we have effective interventions that assist adults who have been abused in childhood to respond effectively to stress," he said.

Prof Young said the research also underscored how "being raised in a stable and safe environment as a child helps us deal with stress in adulthood".

The study is published online in the journal Nature Neuroscience.