A study was published (journal Science, suggested addiction is in part a "disorder of the brain")into drug addicts and abnormalities in the brain which may make some people more likely to become substance misuser, according to scientists at the University of Cambridge.
Their findings were that the same differences in the brains of addicts and their non-addicted brothers or sisters.
Other experts said the non-addicted siblings offered hope of new ways of teaching addicts "self-control".
It has long been established that the brains of drug addicts have some differences to other people, but explaining that finding has been more difficult.
Experts were unsure whether drugs changed the wiring of the brain or if drug addicts' brains were wired differently in the first place.
This study, funded by the Medical Research Council, attempted to answer that by comparing the brains of 50 cocaine or crack addicts with the brain of their brother or sister, who had always been clean.
Both the addicts and the non-addict siblings had the same abnormalities in the region of the brain which controls behaviour, the fronto-striatal systems.
The suggestion is that these brains may be "hard-wired" for addiction in the first place.
The chief pharmacist for Derbyshire Mental Health Trust, David Branford, said the study, "implies that addiction does not produce noticeable changes to brain structure and function which means that there may be provision for looking at new treatment techniques for addiction".
Prof Les Iversen, from the department of pharmacology at the University of Oxford, said: "These new findings reinforce the view that the propensity to addiction is dependent on inherited differences in brain circuitry, and offer the possibility of new ways of treating high-risk individuals to develop better 'self control'.
Partly sourced from BBC health & The University of Cambridge