Alcohol Addiction and Brain Adaptation – The Long Term Impact on the Brain

Alcoholism has a devastating effect on our society. Nearly 130 million Americans have been exposed to it in the family. Untreated addiction costs the US $400 billion a year. That’s six times the cost of treating heart disease and diabetes — and four times the cost of cancer. Not surprising, 40 percent of all traffic fatalities involve alcohol. But did you know more than half of all homicides and domestic violence incidents are alcohol-related?

Of all the ways alcohol affects the world, the most profound is alcohol’s impact on the human brain. Repeated alcohol consumption causes negative and long-lasting changes in the brain’s tiny nerve cells, or neurons. In order to understand exactly how alcohol impacts our brains, let’s start at the beginning: on the day you were born. By this time, your brain had already grown about 100 billion neurons. Neurons are living, growing cells in a vast and evolving network of electrical activity in the brain. Neurons are not fixed like electric wiring. Almost every neuron is constantly changing its function by adapting to bodily demands, sensations, and environmental stimuli.

Each individual neuron in the brain takes in new information and communicates with the other neurons to make sense of it. The transmission of information, from one neuron to another, happens at lightning speed. A neuron can send a signal, reset itself, and send another signal up to 400 times a second. In fact, all the sights, sounds, smells, touch, and other sensations that are experienced by a baby help its brain to create new neural connections. By adulthood, the total number of connections between neurons amounts to 100 trillion.

Connections between neurons are dynamic and change over time. New connections are formed and old ones disappear. The brain’s ”wiring” is, therefore, developed and shaped by life experience. Information coming in through your eyes, ears, and other senses are captured, and your neural connections can change in a split-second, forming new ones. These connections continue to grow and evolve well into adult life.

However, alcohol consumption, and its physical effects such as intoxication and sleepiness, actually disrupts communication between neurons in the brain. Since alcohol is a depressant, it slows down activity in many parts of the brain. The neurons in affected areas control muscles, resulting in relaxation and a lack of coordination. The neurons in affected areas also control speech, causing words to slur and become increasingly imprecise. Similarly, affected neurons control autonomic bodily functions, and heart rate and breathing become impaired.

But, what happens physiologically inside the brain when we drink alcohol? Why do we feel good so quickly after consumption? Well, the pleasure we feel from alcohol, as well as food and sex, comes from the release of the natural brain chemical dopamine. We depend on our brain’s ability to release dopamine in order to experience pleasure from basic human needs like the sight, smell, or taste of food. That experience, no matter how brief, is stored in the hippocampus section of the brain. The same physiological sensations occur when we are sexually aroused and even when we see or smell an attractive mate. Alcohol, in particular, produces very large and rapid surges of dopamine, and the brain responds by reducing its normal dopamine activity.

When you begin to drink, at first the brain gets intoxicated rapidly. It releases a fair amount of dopamine, a natural feel-good chemical, to fight the poison in alcohol. So, it is actually the dopamine that makes you feel good, not the alcohol. Repeated drinking increases the total volume of dopamine released over time. Eventually the brain compensates by lowering its own natural production to combat the effects of alcohol. That is why, over time, it takes more and more drinks to create the same intoxication. The brain malfunctions when it adapts to constantly higher levels of dopamine that are artificially produced by alcohol.

The moment you stop drinking, a void of dopamine is created and a craving ensues. Then, the brain creates a debilitating mood to urge you to drink – in order to raise the dopamine level again. The fastest way to get it back up to its new ”normal” is to drink alcohol. Once this brain malfunction occurs, all activities are affected: from feelings and behaviors to decisions and relationships. This explains why those who abuse alcohol are twice as likely to be divorced than those who do not.

Repeated alcohol consumption causes long-lasting changes in the brain’s neurons. Scientists call this change ”neuroadaptation.” This means that neurons have adapted to drinking, as if it were normal. Let’s say, for example, you start to drink regularly at 6 pm every evening. At first the brain begins to defend against this chemical, since it considers alcohol a poison. It warns you of its effect by causing intoxication, nausea, hangover, and other symptoms. However, as you keep drinking regularly, the brain compensates, allowing you to drink more by producing a stronger tolerance. At this point the neurons get adapted to your drinking patterns.

Now, let’s say you suddenly decide that you are not going to drink tonight at 6 pm. The adapted brain, which now believes alcohol is a normal part of life, will send various signals to remind you it’s time to drink as the clock approaches 6 pm. These signals come in the form of mild to severe withdrawal symptoms, such as irritation, agitation, cravings, and urges. In short, you have basically trained your brain to crave alcohol. (Later, you will learn how re-training the brain is the clear path to recovery.)

At this point one is alcohol-dependent, which is rooted in a change in brain chemistry. Advanced technology — such as Magnetic Resonance Imaging (MRI), diffusion tensor imaging (DTI), positron emission tomography (PET), and electrophysiological brain mapping — indicate that alcohol addiction is less of a behavior problem, and more of a brain malfunction caused by repeated poisoning of the brain.

For years, scientists believed the number of neurons in the adult brain was fixed early in life. If brain damage occurred, new neurons could not be created. Later researchers found new ones are indeed generated in adulthood — a process called “neurogenesis.” New learning ensues, allowing electrical signals to travel along neural pathways more readily. This inherent capacity to change is termed ”plasticity.”

This ability to grow new neurons and form new connections was demonstrated in experiments like the one conducted by Doctors Avi Karni and Leslie Ungerleider at the National Institutes of Mental Health. They had subjects perform a simple finger-tapping exercise — and identified the areas of the brain involved with MRI brain scans. Subjects practiced this motor task daily, gradually becoming faster and more proficient. After four weeks, new brain scans revealed the region of the brain involved in this task had actually expanded. This indicated regular practice and repetition of the task had recruited new nerve cells — and changed the original neural connections.

This finding is the basis for a new scientific hypothesis: inner transformation begins with ”learning” (new neural input), which gradually replaces our ”negative conditioning” (present neural circuitry). The end result is ”positive conditioning” (or new neural circuitry) that directs new emotions and behavior. Hence, the concept of ”re-wiring” the brain for lasting change is a very real and distinct probability.

Alcohol addiction involves the same neural pathways as early memory and learning. So the addictive process weakens all that the brain knew before. Effective recovery involves the reversal of this process. This is a dynamic, comprehensive process that involves what scientists call ”re-training” of the brain — or neuroplasticity. More information on neuroplasticity and its success can be found on the NIFAR website.

Alcohol addiction is truly progressive. In time, it generally gets worse, not better. The behavior patterns associated with alcohol abuse cross all social boundaries, affecting both genders, every ethnic group, and people in every tax bracket. Therefore, new methods to combat this widespread disorder must be used to help those who are suffering. In the process, we will alleviate the massive financial strain of untreated addiction on our healthcare system, which now exceeds $400 Billion a year in America.