Alcoholism is a chronic and progressive disease that has a predictable course, recognizable symptoms, and genetic and environmental foundations. It includes the characteristics of craving, development of tolerance, and withdrawal symptoms when attempting to cut down or stop drinking. Alcoholism drives one to continued drinking in spite of adverse health and social consequences.

The Brain

The real story of alcoholism begins in the brain. Alcohol interferes with the brain's neurotransmitters. GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter and promotes feelings of calmness in the brain. NMDA (N-methyl-D-aspartate) is a glutamate that acts as an excitatory neurotransmitter, promoting activity and growth in the brain. In healthy brain functioning, these two neurotransmitters, as with other brain chemicals, are in balance.

However, alcohol shuts down NMDA and allows GABA to take over. When this occurs, a person experiences slowed communication, reduced motor coordination, slurred speech, and eventually blackouts. NMDA is necessary for learning and memory, so when NMDA functioning is abnormal, learning and memory suffer.

Furthermore, alcohol interferes with the supply of tryptophan, an amino acid that promotes the release of serotonin. Serotonin is another neurotransmitter involved in mood regulation. A decrease in the levels or functioning of serotonin leads to depression and/or anxiety.

Alcohol addiction has also been associated with low levels of MAO (monoamine oxidase) and CREB (cyclic AMP response element-binding protein). MAO is an enzyme that breaks down certain neurotransmitters such as serotonin, norepinephrine, and dopamine. Decreased amounts of MAO are associated with impulsivity, short attention span, pleasure-seeking, and a low pain threshold. CREB is associated with long-term memory formation, and a lowered level has also been associated with anxiety in alcoholics.

Alcohol has harmful effects on the medulla, the part of the brain that controls basic survival functions. Therefore, alcohol can affect the brain's ability to moderate breathing and heart rate. As if that were not enough, alcohol addiction can also lead to premature aging, especially for someone over 40 years of age.

In studies of the brains of alcoholic men, it has been found that there is decreased blood flow to the frontal lobe of the brain, an area associated with memory, creativity, and problem-solving. The nerve membranes are affected, which can lead to structural changes and damage to this part of the brain. An individual who has consumed alcohol heavily for 30 to 40 years may have a brain that weighs as much as 105 grams less than an individual who drank lightly or not at all.

Other Physiological Effects of Alcohol

As significant as the effects of alcohol are on the brain, the rest of the body is not left out. The liver is the primary site where alcohol is metabolized or broken down. When the liver becomes overburdened by having to deal with too much alcohol, it becomes damaged.

Three liver disorders attributed to alcohol are fatty liver (an excessive accumulation of fats, particularly triglycerides, in the liver), alcoholic hepatitis (a combination of fatty liver, inflammation of the liver, and the death of healthy liver cells), and alcoholic cirrhosis (the replacement of healthy liver tissue with non-functioning scar tissue). There is no known cure for cirrhosis and it can lead to liver cancer or complete liver failure, both of which can be fatal.

As with all foods and drinks, alcohol passes through the digestive system — the esophagus, stomach, and pancreas. In the esophagus, alcohol can cause reflux, leading to esophagitis, an inflammation of the esophagus. Complications of alcohol addiction, such as increased blood pressure in the primary vein carrying blood from the intestines to the liver, can also lead to the development of swollen and distended veins in the esophagus. If those veins rupture, death may result.

Gastritis, an inflammation of the stomach lining, is also common in alcoholics. It can prevent the effective absorption of food and medicines, which obviously leads to additional problems. Untreated, gastritis can also be fatal.

Alcohol can inhibit the body's healing process; in the stomach, this can lead to an aggravation of stomach ulcers. Alcohol can start an ulcer through the stimulation of excessive production of gastric juices. The pancreas produces enzymes required for digestion and insulin, which controls blood sugar levels. Pancreatitis, or inflammation of the pancreas, is also common in alcoholics and may be fatal. Heavy drinking can also lead to hypertension (high blood pressure), cardiomyopathy (disease of the heart muscle), and stroke. Binge drinking in particular can cause irregular heartbeats, palpitations, and even sudden death.

Lesser-known effects of alcohol on the body include contributing to osteoporosis in the bones. Gout, a painful swelling of joints, is worsened by alcohol and is quite difficult to treat. Alcohol can cause diseases in the muscles and skin as well. Because of its effects on the immune system, alcohol has played a significant part in the development of tuberculosis, pneumonia, and infections associated with AIDS. Sexual problems due to alcohol include temporary impotence in men and a failure to ovulate in women. Heavy alcohol use is connected with many types of cancer: mouth, larynx, pharynx, esophagus, liver, stomach, colon, rectal, and breast.

Mental Health Problems

With all the effects on the brain that have been presented, it is no surprise that alcohol also leads to many mental health problems.

Primary among these problems are depression and anxiety, related to alcohol's tendency to interfere with neurotransmitters that affect moods. A very serious brain disorder common in long-term alcoholics is called Wernicke's encephalopathy. It is caused by a deficiency in Vitamin B1(thiamine). As alcoholism progresses, the alcoholic's craving for his substance is greater than his desire for food. Malnutrition results, which is where vitamin deficiencies come in to play.

Symptoms experienced with Wernicke's encephalopathy include confusion, drowsiness, poor balance, double vision, and abnormal eye movements.

If untreated, Wernicke's encephalopathy can progress to Korsakoff's syndrome. This is a very serious illness with the key component being memory loss. A person with this disorder can neither recall old events nor form new memories.

Genetics

Many of the research studies done to determine if there is a genetic link to alcoholism involve comparisons between biological siblings, twins, and adopted family members. Studies are consistently finding that biological children of alcoholic parents are two to three times more likely to become alcoholics than biological children of nonalcoholic parents. A study of identical male twins with alcoholic parents found they had 50 to 200 percent greater likelihood of developing alcoholism than fraternal male twins. Identical twins have the same genetic makeup.

Research in this area is really just getting started. Thus far, it seems there may be a genetic link between alcoholism and chromosomes 1 and 4. The dopamine D2 receptor gene (DRD2) and a gene called ankyrin repeat and kinase domain containing 1 (ANKK1) have also been associated with alcoholism.

Although this information on genetics is still being confirmed, it is clear that genetics do play a part in alcoholism. At the same time, it is important to remember that just because a person may have the genetic tendency to become an alcoholic doesn't mean he or she will automatically become one. Many other factors also contribute to the development of alcoholism.