A new study suggests the brain physically adapts to rely on alcohol to relieve stress and anxiety, creating a powerful feedback loop that makes quitting drinking extremely difficult.

Researchers at Scripps Research identified a set of brain cells that become more active when drinkers start associating alcohol with relief from withdrawal. The finding pinpoints a biological mechanism behind addiction, offering more evidence that alcoholism is not just about pleasure or willpower but about deep changes in brain function.

The study, published in Biological Psychiatry: Global Open Science, found the effect occurs in the paraventricular nucleus of the thalamus (PVT), a region that regulates stress and emotion.

“What makes addiction so hard to break is that people aren’t simply chasing a high,” said Friedbert Weiss, the study’s lead author and professor of neuroscience. “They’re also trying to get rid of powerful negative states, like the stress and anxiety of withdrawal.”

“Alcohol is providing relief from the agony of that stressful state,” said co-author Hermina Nedelescu, adding that, like other addictions, alcohol dependence is marked by cycles of withdrawal, sobriety, and relapse.

In the study, rats initially drank for pleasure, but after repeated withdrawal cycles, they sought alcohol to ease symptoms such as depression, nausea, agitation and fatigue — persisting even in uncomfortable situations.

Researchers concluded that negative reinforcement, drinking to avoid pain and the activation of the PVT are key to how addiction is learned and maintained.

The discovery could help develop new treatments for alcohol dependence and anxiety disorders. The team now plans to study gender differences and identify the molecules driving this brain response.

In the U.S., an estimated 14.5 million people have alcohol use disorder, which encompasses a range of unhealthy drinking behaviors, according to the National Institute of Alcohol Abuse and Alcoholism. Alcohol kills three million people worldwide each year, according to the World Health Organization.