Why Is Alcohol Addictive? The Science Behind Alcoholism

By Courtney Cosby “I drank too much last night, and the night before that. I can’t seem to go a night without it anymore. While I am consuming it, it is consuming me.” These are words that sadly come out of the mouths of too many people. Alcoholism is painful both for the individual who can’t stay away from the drink and for the people who love them, as they watch them move through life in a haze. This debilitating disorder leaves individuals and families frustrated while they try to figure out how to solve the problem of alcoholism in their lives. Why is alcohol addictive? What makes it so indispensable to the person who seems to be so ruled by drink? Alcoholism has many causes, with roots in social, genetic, psychological and physiological factors. It was once believed that alcohol affected the entire brain because it was simply a membrane disruptor. Thanks to continual advancements in technology, scientists have discovered that this is not the case as they have found the true culprit of all of the internal chaos that alcohol produces in individuals who are dependent on it.

The Ethanol Molecule

The answer to the question, “Why is alcohol addictive?” can be found by looking at the ethanol (C2H50H) molecule. Here comes the science lesson. Ethanol is the primary chemical compound found in alcoholic beverages that brings about the effects we all associate with alcohol consumption. Its impact on the brain is far-reaching and profound.


A normally functioning human brain maintains a delicate balance of chemicals, called neurotransmitters, which are vital in helping to regulate the body’s function and behavior. Ethanol causes a slowing effect in neurotransmitters. When that balance is offset by ethanol, the typical effects of alcohol are experienced (slurred speech, mood and behavior changes and lack of coordination) due to impaired brain function. More specifically, studies have shown that ethanol is a gamma-aminobutyric acid (GABA) antagonist. GABA is the main inhibitory neurotransmitter in the central nervous system (by way of creating a dramatic rise of chlorine ion release into neurons). GABA-A are receptors that decrease the excitability within neurons, which ethanol actually binds to. GABA-A interferes with the main excitatory neurotransmitter, known as glutamate, which is responsible for carrying signals between nerve cells in the body. Glutamate’s ability to communicate is inhibited when alcohol has been consumed.

Reward Center

The reward pathway is located in the reward center and is responsible for responding to the body as a result of good or bad behaviors by releasing dopamine and serotonin into the body. When alcohol is present, it stimulates these neurotransmitters, causing feelings of euphoria and affecting the individual’s inhibition. When alcohol is used regularly, more alcohol is necessary to achieve the required effects (the feeling of euphoria).

Alcohol’s Effects Over Time: Tolerance, Dependence and Withdrawal

So, why is alcohol addictive? It is enslaving to individuals because the brain adapts to the presence of alcohol over time. The body becomes increasingly tolerant to it and the brain begins to make up for the slowing effects that are caused by the increase in glutamate (the excitatory neurotransmitter). This is the brain’s way of attempting to bring itself back to a normal state. Alcohol tolerance or insensitivity develops at this point and the individual then needs more alcohol to reach the desired effect. As time goes on and this process continues, the desire to drink alcohol develops into dependence. When the body suddenly experiences a lack of alcohol, it has to readjust again, which leads to unpleasant withdrawal symptoms. Prolonged alcohol abuse forces the GABA-A receptor to become less sensitive, which is a contributing factor to some of the common effects of alcoholism, like anxiety and panic disorders. This is due to the central nervous system becoming hyperactive. When an alcoholic drinks, the cycle is repeated and, because of this, many addicts keep drinking to feel normal. Sources: National Institute on Alcohol Abuse and Alcoholism: Neuroscience: Pathways to Alcohol Dependence Harvard Science Review: The Science of Alcohol Addiction U.S. National Library of Medicine: National Institute of Health: The Role of GABAA Receptors in Mediating the Effects of Alcohol in the Central Nervous System

Scroll to Top