Stress and Alcohol: How the Brain’s Stress Signals Drive Habitual Drinking

Stressful moments often lead people to rely on habits like drinking, but why? A new study published in eLife provides one of the clearest explanations yet, uncovering a direct connection in the brain that links stress to addiction-related behaviors.

The research, led by Jun Wang, professor in the Department of Neuroscience and Experimental Therapeutics at the Naresh K. Vashisht College of Medicine at Texas A&M University, shows how alcohol disrupts the brain’s natural stress-response system, impairing its ability to adapt or make sound decisions.

Brain Pathways: Stress Centers Send Signals to Habit Regions

The study identifies a previously underappreciated pathway connecting the brain’s stress centers to the dorsal striatum, a region responsible for habits and decision-making. The stress centers include two small but critical brain regions: the central amygdala (CeA) and the bed nucleus of the stria terminalis (BNST), which activate during feelings of overwhelm, anxiety, or threat.

“What we’ve identified is a direct line of communication between the brain’s stress centers and the region that governs habits and actions, a connection that wasn’t previously understood well. Seeing stress signals travel straight into this decision-making system gives us a clearer picture of why stressful experiences can so strongly influence behavior, sometimes in ways that become unhealthy.”
— Jun Wang, senior author of the study

These stress centers communicate using a chemical called corticotropin-releasing factor (CRF), the brain’s primary stress signal. Until now, scientists did not know how CRF reached the dorsal striatum, which helps control actions and habits.

How CRF Influences Decision-Making

The study reveals that CRF-sending cells in the stress centers send direct projections into the dorsal striatum, targeting specialized cells called cholinergic interneurons (CINs). These cells act as “traffic controllers” in the brain, determining whether we stay flexible and adjust our behavior or fall into automatic habits.

When researchers applied CRF to these cells, their activity increased, boosting the release of acetylcholine, a chemical that supports learning, decision-making, and the ability to adapt plans when needed.

“Under normal conditions, this stress signal actually helps the brain stay flexible, not rigid. It helps us pause, think and make better decisions, especially when something stressful is happening.”
— Jun Wang

Alcohol’s Disruptive Effect on the Stress-Response System

The second major finding shows how alcohol interferes with this adaptive stress response. During early withdrawal, alcohol weakened the ability of CRF to activate cholinergic interneurons. Alcohol also slowed the activity of these cells on its own.

In simple terms: Alcohol blocks the brain’s natural ability to adapt during stress.

“Alcohol essentially cuts the line of communication. When that happens, the brain loses some of its ability to respond to stress in a healthy way. This may push a person toward automatic or habitual behaviors, like drinking.”
— Jun Wang

This disruption could explain why people under stress are more likely to turn to alcohol or other habitual behaviors as a coping mechanism.