It's well-known that the cycle of abuse means that children who have suffered from childhood trauma are often doomed to inflict it on others. In fact, violent individuals' brains often look different than those of average individuals. However, until now it was difficult to determine precisely whether these brain changes were a result of childhood abuse, or whether violent individuals simply possessed different brains than the rest of the population. However, a study published in the journal Translational Psychiatry may have cracked the code.

A team led by Carmen Sandi conducted a study on male rats. While they were young, the male rats were exposed to a variety of psychologically stressful situations. Researchers noted that their childhood experiences shaped these rats into becoming more aggressive, violent adults, which prompted them to take brain scans to see if changes had occurred.

Indeed, they had. "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," Carmen Sandi, of the EPFL's Laboratory of Behavioral Genetics, Brain Mind Institute and the National Centers for Competence in Research SYNAPSY, said in a statement. "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." These exact same brain changes also appeared in the minds of violent human offenders studied by researchers.

The team also found that the psychological stress that the rats experienced during their childhood changed certain genes in the brain. These variants of the MAOA gene cause carriers to be predisposed toward an aggressive attitude. The team found that the rats' experiences caused this gene to be modified.

However, all hope does not appear to be lost. While childhood trauma can certainly not be prevented in every case, researchers may have found a way to reverse its effects. The researchers gave the rats an MAOA inhibitor, an antidepressant in this case, in order to test whether it could minimize their aggressive behavior, and it did.

The researchers will be conducting future studies in order to determine whether childhood trauma's brain changes can be reversed. They will also hope to shed light on whether certain people are more susceptible to trauma due to their genetic makeup.