Cocaine addiction is known to be difficult to treat, given the high risk of relapse. This may be due in part to cocaine altering the brain, making users more prone to relapse, especially in times of stress, a new study finds.

Published in The Journal of Neuroscience, the study could pave the way for specialized treatment to help recovering cocaine addicts maintain long-term abstinence. “Relapse among cocaine addicts is a major problem. We wanted to find out what causes it,” said Dr. Peter McCormick, from the UK’s University of East Anglia. He and his colleagues studied the brains of lab rats who had been administered cocaine.

The researchers focused on the interaction between two neuropeptides (protein-like molecules) in the brain that carry information between neurons, in the part of the region of the brain responsible for reward, motivation, and drug addiction.

“We had speculated that there might be a direct communication between neuroreceptors controlling stress and reward,” said McCormick. “When we tested this, we found this to indeed be the case.”

They found evidence that cocaine binds to these two crucial neuropeptides and “promotes long-term disruption” and “sensitizes cells to the excitatory effects” of the neuroreceptors, causing stress to trigger cravings for the drug. “These changes could increase the risk of relapse under stressful conditions,” McCormick said.

Significantly, researchers also identified a potential way to restore the connection that may protect against relapse. They believe the mechanism could be used to aid in addiction treatment in humans. “By restoring the broken interaction, we may be able to minimize stress-driven relapse in addicts,” said McCormick. “This research lays the groundwork for the development of such approaches.”