Addiction Runs in the Family

Drug addicted and non addicted siblings share similar brain abnormalities

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Drug addiction may be more genetic than we think. People who are addicted to drugs share similar brain abnormalities with their siblings, in the brain region that manages self-control - even if the sibling isn't drug-dependent.

These new findings allow us to understand more about why people with a family history of drug abuse are themselves at a higher risk of addiction.

"If drug addiction runs in your family, call a therapist."

Dr. Karen Ersche of the University of Cambridge in England led a recent study into these related brain abnormalities. Her research group scanned the brains of 50 adult sibling pairs, in which one of the siblings was addicted to cocaine while the other did not abuse either drugs or alcohol.

The brain scans were then compared to 50 unrelated, healthy volunteers who had no personal or family history of drug addiction.

The Cambridge Drug Addiction Research group found that the drug-dependent subjects and their non-addicted siblings all had abnormalities in the fronto-striatal systems of the brain - the area that allows a person to exercise self-control.

The drug-dependent siblings had more extensive abnormalities that became more severe with longer duration of drug abuse; but the healthy controls did not show the related abnormalities that the non-addicted siblings exhibited.

In the image above, abnormal fibres in the brain (in yellow) and enlarged amygdala (in blue) and putamen (not shown) of both sibling pairs are shown as compared with healthy controls.

“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," said Dr. Ersche.

"Our findings now shed light on why the risk of becoming addicted to drugs is increased in people with a family history of drug or alcohol dependence: parts of their brains underlying self-control abilities work less efficiently.”

The research team plans to study how the siblings who don't take drugs manage to overcome their own brain abnormalities, to understand what makes the siblings who don't abuse drugs more resilient to addiction.

The researchers hope that this will provide vital clues for developing more effective therapies to help people with addiction.

The study was funded by the U.K.’s Medical Research Council. The findings were published in the February 2012 issue of Science.

Image provided courtesy of the University of Cambridge.

Reviewed by: 
Review Date: 
February 7, 2012
Last Updated:
February 8, 2012