A new study undertaken by scientists at Cambridge University has shown that addiction may be a result of physical differences in the brain, which makes some people more susceptible to drug addiction than others. The study was funded by the Medical Research Council and published in the journal Science; using hospital scanners the researchers analysed the brains of 50 regular cocaine users and their non drug using siblings. Results showed similar brain abnormalities in both the drug users and their siblings. As a control another 50 healthy volunteers were compared, who did not prove to have these abnormalities which suggest a genetic basis for addiction.

Previous research has found similar abnormalities relating to self control in drug users however it was never clear if they were a cause or consequence of the drug misuse. The scans showed that both the drug addicts and their non-addict siblings shared similar defects in the nerve fibres that communicate with the temporal cortex which is involved in controlling impulsive behaviour. This new evidence suggests that indeed some people are more prone to addictive behaviour than others however the implications of this study are wider reaching.

Although drug users would love to blame genetics for their addiction, the study also shows that the siblings of the cocaine users had, despite the genetic predisposition, been able to remain drug-free. The fact that the siblings of the drug addicts who share the same brain abnormality which supposedly increases their vulnerability of addiction manage to resist it is extremely promising for drug-addicts. This new information could be used for the treatment of current addicts who could gain to benefit from new research into the increased self control of the non-addict siblings.  

Dr Karen Ersche of the University said, “Cocaine is a highly addictive drug but only some people get hooked on it. However, your chances of getting hooked rise about eight times if you have a family member who is addicted.” Dr Ersche further states that their findings suggest that, “drug addiction is not a failure of character or a life-style choice. It’s a problem with the brain. If your brain is wired for addiction it’s easier for the drugs to take over, but the good thing is that this is not inevitable.” 

The next stage of the research will aim to shed light on why the drug-free siblings had greater success in avoiding getting hooked, it inevitably goes back to a question of nature or nurture which is one that will continue to be debated for many years to come.

“While we still have more work to do to fully address the reasons why some family members show a greater resilience against addiction, our results will provide the scientific basis for the development of more effective prevention and treatment for people at risk,” Dr Ersche said.