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Effects of Alcohol on the Brain

 Alcohol Rehab

Few activities are as surrounded by medical myths as much as the consumption of alcohol. From claims that drinking directly kills your liver to tips on how to mitigate the effects of alcohol on brain and body, there’s a lot of information and misinformation out there. If you’re worried about issues related to alcohol addiction and substance use disorders, it’s wise to learn more about the way impairment occurs and how it can adversely impact one’s life.

Lethal Effects

For those who’ve developed biologically driven addictions to drinking, there are a number of potentially lethal or dangerous outcomes in the cards. Patients experiencing withdrawal symptoms, for example, have been known to experience full cardiovascular and respiratory collapses leading to death. Delirium tremens, generally referred to as the DTs, may develop within 72 hours of not consuming a drink. Symptoms can range from types of hyperpyrexia to ketoacidosis although extreme cases only appear in 5 percent of people. These can lead to everything from long-term brain damage to death. Some people even experience visual and auditory hallucinations.

To say that the brain goes for a rough ride is an understatement, especially when dealing with the up-and-down cycle of drinking and not drinking. People often jokingly refer to this as the product of brain cells being killed, but recent studies have shown that extreme drinking does not directly kill brain cells. Simply put, the quantity of alcohol needed to kill one of your brain cells would be enough to kill your body. Some research indicates that a few white brain cells, the ones responsible for spatial reasoning, may actually be killed, but the gray brain cells that handle most everything else are not hit.

Thiamine Deficiency

Gray brain cells can die off as one of the long-term indirect effects of alcohol on the human brain. The most likely culprit that modern science has identified is a deficiency of thiamine, a vitamin that’s in the B complex family. It allows your body to metabolize a number of important nutrients, including glucose, lipids and amino acids. Glucose and lipids are critical to both providing energy and building structures in your body, and amino acids play a role in everything from cell division to neurotransmission.

Thiamine deficiency, however, takes quite a bit of time to accumulate to the point that it can seriously impair the brain even when you’re not drinking. Even in cases where heavy drinking has gone on for quite a while, most people will be able to reverse the effects once they significantly cut back intake. In some instances of chronic and long-term consumption, individuals can begin to suffer irreversible brain damage.

The short-lived version of this disorder is called Wernicke’s encephalopathy, known as WE. WE can lead to neurological problems resulting in mental confusion, eye movement problems and stumbling. In at least 80 percent of cases of heavy alcohol misuse, a disorder known as Korsakoff’s psychosis can develop. These individuals often display signs of retrograde amnesia, meaning they can’t recover older memories anymore. They may also forget conversations they’ve had just an hour after the fact. There is still some scientific debate about whether WE or Korsakoff’s psychosis comes first, but the relationship between the two is considered very strong.

Smaller Brains

The brain itself can physically shrink as a result of heavy liquor consumption. Individuals who experienced prenatal exposure to alcohol are more likely to suffer from brain shrinkage as are women in general. This can lead to a host of problems, including trouble learning.

Immediate Impairment

Drinking immediately begins to impair the brain once it’s in a person’s system. While these effects are generally temporary for non-chronic drinkers, they can still be alarming even in the short run. People may experience slurred speech, blurred vision, diminished reaction times and difficulty walking.

One particularly disturbing effect of impairment is blackouts, a common euphemism for memory lapses caused by recent drinking. A survey of college students indicated that nearly 40 percent reported they had experienced at least one blackout in the last year, and more than 50 percent had experienced one at some point in their lives. Blackouts are more common among women than men. There are a number of concerns about blackouts, especially given the risky behaviors commonly associated with heavy drinking, including drunk driving and unprotected sex.


Heavy drinking and malnutrition are co-morbid for a variety of reasons, but general malnutrition has been proven to be bad for the brain. Many of the effects of malnutrition on the brain parallel the ones that drinking causes. Malnutrition and heavy drinking are common among college-age women, for example, because of the relationship between heavy social consumption and anorexia, a term now commonly called drunkorexia. This can give rise to a dangerous feedback loop.

Alcohol also leads to changes in how dopamine is released by the brain. Dopamine influences reward-seeking behaviors in almost all mammals, and this can significantly skew the feelings of reward from eating to alcohol consumption. There also are compounding effects related to alcohol and dopamine because alcoholic drinks are often consumed in social settings that people find rewarding, reinforcing the links that make social drinking so difficult for many people to escape.

Since drinking can supply a sense of reward, it may reduce the urge to eat. Even the anticipation of a drink can fire up the brain’s rewards centers. This may reinforce malnutrition and its effects.

The Cerebellum

Responsible for coordinating thoughts with movements, the cerebellum has the misfortune of being the part of the brain that’s most vulnerable to the thiamine deficiencies that alcoholic drink consumption can trigger. The cerebellum also plays a role in learning. Some individuals appear to have stronger genetically predispositions to thiamine deficiencies and sensitivities, and this may explain why a minority of heavy drinkers go on to develop brain damage so severe that they require long-term care while others only experience temporary cognitive problems.

The Cerebral Cortex

Most of your information-processing capabilities are located in the cerebral cortex, and a number of the effects of alcohol on brain function are most directly experienced here. The cerebral cortex is the part of the brain that makes you feel like you. As the processing of signals from the ears and eyes slows down here, you begin to feel sluggish. Socially wired inhibitions are also housed in the cerebral cortex, and this is why heavy drinking is often associated with a breakdown of social norms. In other words, drinking’s influence on the cerebral cortex is why some people feel that alcohol helps to open up their personalities.

The Hypothalamus and the Pituitary Gland

These two parts of the brain drive the release of hormones. If one thinks of the stereotype that alcohol improves sexual drive while also ruining sexual function, this is where those mixed feelings get set into motion. Individuals also suffer from a variety of other problems due to negative effects on circadian rhythms and the immune system originating in these parts of the brain. There is some suspicion that the impact of alcohol on the hypothalamus and the pituitary may also play a role in increased cancer risk.

The Medulla

Responsible for regulating a host of involuntary functions, the medulla is sensitive to alcohol exposure. This can give rise to the general sense of shutting down that comes from being severely drunk. The medulla handles automatic functions, including regulating body temperature and breathing, and this is one of the reasons that extreme drinking can be life-threatening. It also plays a role in maintaining consciousness, and that’s why people can feel themselves slipping away as they get wasted.


One of the things that makes alcohol impairment so difficult to cope with is that it has a tendency to hit you both coming and going. This effect is the result of the fact that alcohol is at once a direct depressant and also an indirect stimulant. The chemicals primarily responsible for these feelings are glutamate and gamma-Aminobutyric acid, commonly called GABA.

GABA is a neurotransmitter that’s linked to excitability in nearly all animals. Increased uptake of GABA is related to a reduction in excitability, and this is one of the reasons that, for example, certain marijuana strains are prescribed to treat anxiety. An increase in GABA production has an inherently sedative effect, and benzodiazopenes, a drug commonly prescribed to treat alcohol withdrawal symptoms, promotes it. This is one of the reasons that mixing alcohol and benzodiazopenes can have lethal effects: It can lead to a drop in neurotransmission, ultimately slowing the respiratory system and the heart to dangerously low levels.

Alcohol also inhibits the uptake of glutamate, a neurotransmitter that has the opposite effect, promoting excitement and satisfaction. This can lead the brain’s internal pathways to slow down significantly.

N-Methyl-D-aspartic acid, usually styled as NMDA, is an amino acid that mimics the function of glutamate. It plays a critical function in synaptic plasticity, meaning it influences how well you pick up new ideas and skills during the learning process. It’s believed that alcohol’s influence on NMDA in the brain leads to an array of long-term problems, particularly habit formation that leads to addiction and cravings. These effects may be compounded by the reinforcing role that dopamine release plays in the addiction process. Researchers also believe that this is how tolerances are built up.

Liver Function

At first glance, the role that liver function plays in the effects of alcohol on brain activity may seem a bit abstract. Alcohol is known to reduce liver function over time as the body struggles to keep up with filtering out what it perceives to be a poison. The liver, however, also does the job of handling much of the metabolizing of vitamins and amino acids that the brain depends on, in particular the B complex vitamins.

A serious drop in liver function can reduce the ability of the body to generate the things it needs to hold off the worst effects of alcohol on brain damage. This can produce a runaway effect once the liver stops fully doing its job.

Complex Interactions

Given that drinking has a major influence on so many different parts of the brain, the effects can be highly unpredictable. These interactions are made more complex by interactions with other parts of the body, such as the liver and the endocrine system. One person may be disposed to serious alcohol-related brain damage due to thiamine deficiencies and have little trouble with withdrawal symptoms while another individual might have a relatively unharmed brain but experience episodes of dementia during withdrawal.

These unpredictable outcomes are some of the reasons why many people seek professional help when trying to recover from heavy drinking. Working in a structured environment with guidance, one can avoid potential pitfalls, such as mixing alcoholic drinks with benzodiazepines. Social support, including group sessions, helps provide a substitute for the previous dopamine-driving interactions that people have at parties, bars and clubs. By taking a deliberate approach, it is possible to chart a path to a healthier future.

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