South Korean scientists have identified a substance that causes a drug addict to become more strongly addicted under stress, the science ministry said Wednesday, suggesting a way to lower the chance of repeat addiction.

It was confirmed that people with previous records of drug addiction are more prone to become addicted again when placed under significant amounts of stress, but how exactly stress works to increase the chance of repeat addiction has not been verified, according to the Ministry of Education, Science and Technology.

In a study partly funded by the ministry, a joint team of scientists from Seoul National University and Korea University has confirmed that dopamine receptor D2 causes synapses to mutate under the influence of addictive drugs, such as cocaine.

This mutation of the synapses later causes a formerly addicted person to again desire addictive substances when placed under stress, the researchers said. A synapse is a mechanism that allows neurons or nerve cells in the brain to pass an electrical or chemical signal to other neurons.

The effect of DRD2 on repeat addiction was confirmed in a lab test where a group of normal mice and another group of mice lacking DRD2 were first addicted to cocaine and then placed under stress.

The normal mice were found to be susceptible to repeat addiction while those lacking DRD2 showed no such signs, the researchers said.

“The study is significant in that it has confirmed stress is more linked to repeat addiction than to first-time addiction and by verifying the work of dopamine receptor D2 in the process, suggesting a possible way to treat repeat drug addiction, which is one of most difficult neurological disorders to be treated,” Baik Ja-hyun, a lead researcher in the study and professor from Seoul’s Korea University, was quoted as saying.

The findings were published Wednesday in the Nature Communications, a weekly scientific journal published by the Nature Publishing Group, the publisher of international journal, the Nature. (Yonhap News)