People become hooked on heroin and cocaine because this happens to their brain

By Gwyn Wright via SWNS

Heroin and cocaine addicts become hooked because different parts of the brain become worse at communicating with each other, according to new research.

Addicts’ brains contain less white matter than people who don’t take the Class A substances, say scientists.

White matter connects everything in the brain together and helps us to transmit signals.

Researchers have previously found less white matter in drugged-up animals in the lab but the new study is the first to suggest human addicts’ brains also contain less of it.

Academics in the US studied the links between the prefrontal cortex, a part of the brain which enables us to perform everyday tasks and affects our personality, and the habenula, a region that plays a critical role in our understanding of risks and rewards.

The habenula has been found to be a driver of addiction in animals.

Signaling from the prefrontal cortex to the habenula is disrupted in cocaine-addicted rodents, suggesting it plays a role in withdrawal and relapse.

The team say this pathway is still not well understood in humans.

For the study, researchers used MRI scans to investigate the prefrontal cortex- habenula pathway in human heroin and cocaine addicts and a control group of healthy people.

In cocaine addicts, they found white matter had degenerated in that pathway.

People who had recently stopped taking cocaine and heroin addicts also had an impaired pathway.

“Abnormalities in this path may be generalized in addiction," said the study’s first author Sarah King, a PhD student at the Icahn School of Medicine Mount Sinai.

“Importantly, we found that across all addicted individuals, greater impairment was correlated with earlier age of first drug use, which points to a potential role for this circuit in developmental or premorbid risk factors.”

The findings were published in the journal Neuron.