OXFORD, Miss. — Severe stress may do more than take a mental toll — it can actually alter the brain in ways that leave people more vulnerable to addiction, according to new research from the University of Mississippi.
Science has long shown a link between stress and substance misuse, but researchers believe they’ve uncovered part of the reason why.
The researchers focused on two key areas of the brain: the prefrontal cortex, the region tied to decision-making, and the ventral tegmental area, which drives motivation and reward-seeking.
After a series of stressful events in animal models, they saw opposite effects in the two regions. Activity in the prefrontal cortex dropped, suggesting weaker decision-making, while activity in the ventral tegmental area surged, amplifying the urge to seek rewards.
In other words, extreme stress may make risky behaviors like substance misuse more tempting and harder to resist.
“After that experience of repeated stress, something is changing in the brain,” said researcher Alberto Del Arco Gonzalez. “Stress is a physiological response. We are supposed to stress from time to time and then recover from it, but this kind of repeated, intense stress produces effects that might persist for a long time. This is what is important because this can be the starting of a transition from a healthy brain to a brain with an addiction, substance use disorder, or another psychiatric disorder.”
Del Arco said understanding the biology of stress and addiction may help improve both prevention and treatment of substance use disorder.
The National Institutes of Health funded the research, which was published in the Society for Neuroscience’s eNeuro.
