Stress & Addiction: Research Identifies How Stress Triggers Drug Relapse

Recent research from Brown University could pave the way for new methods of treatment for those recovering from addiction. Researchers identified an exact brain region in rats where the neural steps leading to drug relapse take place, allowing them to block a crucial step in the process that leads to stress-induced relapse.

Prior research has established that acute stress can lead to drug abuse in vulnerable individuals and increase the risk of relapse in recovering addicts. But the exact way that stress triggers the neural processes leading to relapse is still not clearly understood. The Brown study provides new insights on how stress triggers drug abuse, and could lead to more effective treatments for addiction.

According to the study, stress has significant effects on plasticity of the synapses on dopamine neurons in the ventral tegmental area (VTA), the brain region where the neural activities leading to a stress-induced drug relapse take place.
Stress activates kappa opioid receptors (KORs) in the VTA, and the researchers found that by blocking the KORs, they could prevent the rats from relapsing to cocaine use while under stress.

Published this week in the journal Neuron, the study shows blocking these receptors may be a critical step in preventing stress-related drug relapses in humans, as well. The chemical used to block the receptor, "nor-BMI," may eventually be tested on humans, according to the study's authors.

“If we understand how kappa opioid receptor antagonists are interfering with the reinstatement of drug seeking we can target that process,” senior study author Julie Kauer said in a statement. “We’re at the point of coming to understand the processes and possible therapeutic targets. Remarkably, this has worked.”

Kauer noted that the study builds upon over a decade of research on how changes in brain synapses relate to behaviors like addiction. The advance is significant, and could accelerate progress towards a medication for those struggling to recover from addiction.

“If we can figure out how not only stress, but the whole system works, then we’ll potentially have a way to tune it down in a person who needs that,” Kauer said.