A brain imaging study carried out at Massachusetts General Hospital (MGH) reveals abnormalities in the cortex – the outer surface of the brain – of cocaine addicts that appear to correlate with dysfunction in areas responsible for attention and for reward-based decision-making.

Rats that voluntarily use cocaine show a persistent cellular memory in the brain’s reward center even after several months of abstinence from the drug, while their involuntary counterparts had no such memory, according to a new study by researchers at the University of California, San Francisco.

The first large-scale analysis of proteins in the brains of monkeys addicted to cocaine reveals new information on how long-term cocaine use changes the amount and activity of various proteins affecting brain function.

New drug research suggests that teens may get addicted and relapse more easily than adults because developing brains are more powerfully motivated by drug-related cues. This conclusion has been reached by researchers who found that adolescent rats given cocaine – a powerfully addicting stimulant – were more likely than adults to prefer the place where they got it.

New research in monkeys suggests the feasibility of treating cocaine addiction with a “replacement” drug that mimics the effects of cocaine but has less potential for abuse – similar to the way nicotine and heroin addictions are treated.

Cocaine addicts often suffer a downward emotional spiral that is a key to their craving and chronic relapse. While researchers have developed animal models of the reward of cocaine, they have not been able to model this emotional impact, until now.

Many studies on cocaine addiction - and attempts to block its addictiveness - have focused on dopamine transporters, proteins that reabsorb the brain's "reward" chemical once its signal is sent. Since cocaine blocks dopamine transporters from doing their recycling job, it leaves the feel-good chemical around to keep sending the pleasure signal.