Childhood trauma leads to violent behaviour in adulthood
Psychological wounds inflicted when young leave lasting biological traces-and a predisposition toward violence later in life, scientists have claimed.
EPFL Professor Carmen Sandi and team demonstrate for the first time a correlation between psychological trauma in pre-adolescent rats and neurological changes similar to those found in violent humans.
"This research shows that people exposed to trauma in childhood don't only suffer psychologically, but their brain also gets altered," Sandi, Head of EPFL's Laboratory of Behavioral Genetics, Director of the Brain Mind Institute, and a member of the National Centers for Competence in Research SYNAPSY said.
"This adds an additional dimension to the consequences of abuse, and obviously has scientific, therapeutic and social implications," Sandi said.
The researchers were able to unravel the biological foundations of violence using a cohort of male rats exposed to psychologically stressful situations when young.
After observing that these experiences led to aggressive behavior when the rats reached adulthood, they examined what was happening in the animals' brains to see if the traumatic period had left a lasting mark.
"In a challenging social situation, the orbitofrontal cortex of a healthy individual is activated in order to inhibit aggressive impulses and to maintain normal interactions," Sandi said.
"But in the rats we studied, we noticed that there was very little activation of the orbitofrontal cortex. This, in turn, reduces their ability to moderate their negative impulses. This reduced activation is accompanied by the overactivation of the amygdala, a region of the brain that's involved in emotional reactions," the researcher added.
Other researchers who have studied the brains of violent human individuals have observed the same deficit in orbitofrontal activation and the same corresponding reduced inhibition of aggressive impulses.
The study is published in the journal Translational Psychiatry.