Violence dramatically alters victims’ brains

Victims of violence undergo brain changes that may make them more sensitive to the rewarding effects of drugs, according to research presented Friday during APA’s Annual Convention.

In a study published in Psychopharmacology (Vol. 197, No. 2), Klaus Miczek, PhD, and colleagues gave two groups of rats the opportunity to ingest cocaine. Some of the rats had recently lost a fight with another rat. The researchers found that these stressed rats took more cocaine, took it faster and didn’t stop.

A number of brain mechanisms may spur this, said Miczek, a psychology, psychiatry, pharmacology and neuroscience professor at Tufts University:

* After being defeated in a fight, rats show an increase of dopamine in their brains – a curious finding given that the neurotransmitter is generally associated with rewarding activities, such as eating and mating.

* In the long term, the rat victims’ brains also showed an increase in glutamate receptors, which past research has implicated in cocaine addiction.

No one has yet translated these findings to humans, Miczek added. But it’s possible that such brain changes may pave the way for mistreated children to become drug addicts later in life.