Alcohol habitually consumed to relieve stress in youth can trigger a decline in the brain's cognitive function once a person reaches middle age, according to a newly published study.
Stress and Drinking: A Vicious Cycle That Fuels Each Other
A recent experiment by researchers at the University of Massachusetts Amherst (UMass Amherst) found that when people repeatedly drink to excess to relieve stress in early adulthood, changes in brain function persist even after a long period of abstinence. The research team led by Professor Elena Vazey published these findings in the international journal "Alcohol: Clinical and Experimental Research."
Alcohol gives the illusion of easing stress at the moment it is consumed, but when this is repeated, the brain's own ability to regulate stress weakens, according to the analysis. To achieve the same effect, a person must drink more frequently and in greater amounts, and the resulting decline in judgment creates new stress, forming a vicious cycle, the researchers explained.
The researchers had mice, which have a neural structure similar to humans, experience chronic stress and drinking together during early adulthood, then abstain over the long term, and analyzed their learning ability, decision-making ability, drinking-relapse behavior, and brain changes in middle age. The results showed that the impact when the two factors acted together was greater than when each acted alone, and that a clear decline appeared in "cognitive flexibility," the ability to adapt to changing situations, rather than in learning ability.
Cognitive Flexibility and the Locus Coeruleus: Traces Left in the Brain
The researchers also analyzed the locus coeruleus (LC), a small region within the brainstem. This region plays a key role in adjusting judgment to fit circumstances, and in a normal brain, it returns to its original state once stress is relieved.
In mice exposed to both alcohol and chronic stress, the locus coeruleus lost the molecular mechanism to normalize itself, and levels of oxidative stress commonly observed in the brains of Alzheimer's patients also rose. This damage barely recovered even after a long period of abstinence, and the researchers viewed this oxidative damage as one possible reason people seek alcohol again even after quitting.
According to statistics from the Korea Disease Control and Prevention Agency, however, drinking rates among people in their 20s and 30s have shown a downward trend, falling from 64.6% to 63.0% and from 69.2% to 65.3%, respectively, in 2024 compared with 2020. Experts advise that preparing healthy ways to relieve stress, such as exercise or hobbies, instead of drinking is the path to protecting long-term brain health.
