Scientists discover molecule in brain could use to cure cocaine addiction

The research, published online by the journal Biological Psychiatry, shows that blocking hypocretin may reduce compulsive drug-seeking behaviour when tested on rats.

Study co-author Professor Marisa Roberto, from The Scripps Research Institute (TSRI) in America, said: “Cocaine addiction is a disorder that affects millions of people worldwide.

Scientists said that addiction seems like a simple concept – taking a drug motivates a person to continue to take it – but that the molecules in the brain that drive addiction are more complex.

For the study, one group of rats was given the option to self-administer cocaine for one hour a day, mimicking conditions of short-term, occasional drug use.

A second group had the option to self-administer cocaine for six hours a day, which mimicked the conditions that lead to compulsive drug use and addiction. Scientists found that compulsive cocaine use triggers a dangerous cycle in the brain, with cocaine sensitising the hypothalamic hypocretin/orexin (HCRT) system, which motivates further drug-seeking.

Specifically, compulsive cocaine use leads to increased hypocretin, which contributes to over-activity in the part of the brain linked to stress.

Professor Roberto added: “The rats escalated their daily intake as many human users would.”

She said that giving the rats medicine to block the over-activity at one of the two receptors in that part of the brain made them stop wanting drugs as often – suggesting potential treatments could be created for cocaine addiction or relapse.