This research will help people understand why it is more likely, for people who have a history of drug abuse in their families, to actually develop the addiction, than those without any family history of drug addiction or abuse.
The researchers compared 50 healthy participants' brain scans with the brain scans of 50 pairs of siblings. In the pairs of siblings, one was addicted to cocaine, and the other sibling did not use alcohol or drugs at all.
The findings determined that the person addicted to the cocaine, and their sibling, possessed brain abnormalities in an area of the brain called the frontal-striatal system.
The drug-dependent person and his/her non-dependent sibling displayed abnormalities in the frontal striatal region (yellow/blue), compared to healthy controls. The drug-dependent siblings had further abnormalities (green) which grew the longer their cocaine abuse went on for.
Dr. Karen Ersche says:
"It has long been known that not everyone who takes drugs becomes addicted, and that people at risk of drug dependence typically have deficits in self-control.
Our findings now shed light on why the risk of becoming addicted to drugs such as cocaine further exacerbates this problem, paving the way for addiction to develop from occasional use."
"The next step will be to explore how the siblings who don't take drugs manage to overcome their brain abnormality in daily life."
The abstract of the journal says these findings support the idea of an underlying neurocognitive endophenotype for stimulant drug addiction.