Alcohol causes the brain’s reward system to release dopamine, a “feel-good” chemical that creates sensations of pleasure. But chronic heavy drinkers don’t feel good for long. Over time, chronic drinking actually depletes the amount of dopamine in your brain, causing you to crave more alcohol and laying the groundwork for an alcohol addiction.
Alcohol has a powerful effect on dopamine activity in the brain. When we drink, the brain’s so-called reward circuits are flooded with dopamine.
This produces euphoric feelings — or what we recognize as feeling “buzzed.”
Dopamine also activates memory circuits in other parts of the brain that remember this pleasant experience and leave you thirsting for more. But over time, alcohol can cause dopamine levels to plummet, leaving you feeling miserable and desiring more alcohol to feel better.
Dopamine is a neurotransmitter — a chemical messenger that carries signals between brain cells and communicates information throughout the body.
The brain uses billions of neurotransmitters to manage everything from our breathing to our heartbeat to our digestion.
Activities such as eating, hugging and exercising can generate dopamine production in the brain.
Dopamine plays many important roles in the body, affecting moods, memory and sensations of pleasure and pain. The chemical is also involved in movement, motivation and reinforcement. It’s the chemical that drives us to seek food, sex and exercise and other activities that are crucial to our well-being and survival.
Individuals with low dopamine levels may experience a loss of motor control, such as that seen in patients with Parkinson’s disease. They can also develop addictions, cravings and compulsions, and a joyless state known as “anhedonia.” Elevated levels of dopamine can cause anxiety and hyperactivity.
Unfortunately, some diseases can disturb the brain’s delicate balance of dopamine. Parkinson’s disease and certain metabolic disorders, for instance, can deplete dopamine.
So can drugs and alcohol.
While drinking initially boosts a person’s dopamine levels, the brain adapts to the dopamine overload with continued alcohol use. It starts to produce less of the chemical, reduce the number of dopamine receptors in the body and increase dopamine transporters, which ferry away the excess dopamine in the spaces between brain cells.
As dopamine levels plummet, so does your mood. As a result, people with an alcohol addiction may consume even more alcohol in an unconscious effort to boost their dopamine levels and get that spark back.
Research is shedding more light on the role dopamine plays in alcohol addiction.
A small study by researchers at Columbia University revealed that the dopamine produced during drinking is concentrated in the brain’s reward center. The study further found that men exhibit a greater release of dopamine when they drink than women.
These findings could explain why men are more than twice as likely as women to develop an alcohol use disorder.
Other research indicates that some people tend to have a higher release of and response to dopamine than others. In addition, those individuals may be predisposed to drink more heavily and develop an alcohol addiction.
Researchers at McGill University in Canada performed positron emission tomography (PET) brain scans on 26 social drinkers and noted a “distinctive brain response” in the higher-risk subjects after they consumed three alcoholic drinks.
Marco Leyton, a professor and addiction researcher at McGill University’s Department of Psychiatry, said in a 2013 press release that participants more at risk for developing alcoholism had “an unusually large brain dopamine response” when they took a drink.
Leyton theorized that the large response might “energize reward-seeking behaviors” and counteract the alcohol’s sedative effects. Likewise, those who have a minimal dopamine release when drinking “might find the sedative effects of alcohol especially pronounced.”
Researchers are also investigating whether drugs that normalize dopamine levels in the brain might be effective for reducing alcohol cravings and treating alcoholism.
In clinical trials in Sweden, alcohol-dependent patients who received an experimental drug called OSU6162, which lowers dopamine levels in rats, experienced significantly reduced alcohol cravings.
Pia Steensland, an associate professor at the Department of Clinical Neuroscience at the Karolinska Institutet and co-author of the studies, said the patients who received the drug “reported not enjoying the first zip of alcohol as much as” patients who did not receive the drug.
Interestingly, those with the poorest impulse control — who would be considered most at risk of relapse after a period of sobriety — responded best to the treatment.