Drinking alcohol to cope with stress in early adulthood may cause lasting brain changes, even years after someone stops drinking, according to new research from the University of Massachusetts Amherst. The study suggests those effects can begin to emerge by middle age, reducing mental flexibility, increasing the risk of returning to alcohol during stressful periods and contributing to patterns of cognitive decline linked to dementia and Alzheimer’s disease.
Supported by the National Institute on Alcohol Abuse and Alcoholism, researchers studied mice, whose brain systems closely resemble those of humans. They found the combination of alcohol and stress has a particularly powerful impact on the brain, far greater than either factor alone.
That interaction appears to create long-lasting changes in brain function. Even after extended periods of sobriety, people who drank heavily to cope with stress in early adulthood may be more likely to return to alcohol later in life.
By middle age, researchers found that learning ability remained relatively intact. What declined instead was cognitive flexibility, the ability to adapt, problem-solve, and respond to new situations.
“Middle age is when problems start to add up,” Elena Vazey, an associate professor of biology at UMass Amherst and the paper’s senior author, said in a press release. “We know that alcohol is a risk factor for early cognitive decline, and we saw that this alcohol-stress combination creates the kind of trouble adapting to changing situations that also happens in the early stages of dementia.”
To understand why, researchers focused on a part of the brainstem called the locus coeruleus, which plays a key role in decision-making and responding to stress.
In a healthy brain, this region activates during stress and then returns to normal once the stress passes. But in brains with a history of heavy drinking and stress, researchers say that the “off switch” appears to break down, impairing decision-making.
The researchers also found signs of oxidative stress, a type of cellular damage commonly associated with Alzheimer’s disease. Even after long periods without alcohol, the brains of previously heavy-drinking mice showed limited ability to repair that damage.
“The brain can really struggle to recover from a history of chronic stress and drinking in early adulthood,” Vazey said.
The findings suggest that long-term brain changes may play a role in relapse and cognitive decline.
“The brain’s wiring system is damaged, which means quitting drinking or making better decisions isn’t a matter of willpower. After a history of stress and drinking, the brain simply works differently, and our treatment strategies need to be able to address these long-lasting differences,” Vazey said.
