In the United States, approximately 8 percent of people aged 18 and older suffer from alcohol abuse and/or dependence. This abuse or dependence costs upwards of $1.7 billion in medical treatment, lost earnings, casualty damages and criminal/legal costs.
Alcohol abuse has been a rising problem over the past three decades. With the continued exposure to alcohol, how does the human body respond or adapt? The body's increased tolerance to alcohol involves the following changes:
- Increase in level of liver's enzymes that are used to break down alcohol
- Increase in activity of brain and nervous-system neurons
These bodily adaptations change a person's behavior. The levels of alcohol dehydrogenase and aldehyde dehydrogenase in the liver increase in response to long-term alcohol exposure. This means that the body becomes more efficient at eliminating the high levels of alcohol in the blood. However, it also means that the person must drink more alcohol to experience the same effects as before, which leads to more drinking and contributes to addiction.
The normal chemical and electrical functions of nerve cells increase to compensate for the inhibitory effects of alcohol exposure. This increased nerve activity helps people to function normally with higher BAC; however, it also makes them irritable when they are not drinking. Furthermore, the increased nerve activity may make them crave alcohol. Most certainly, the increased nerve activity contributes to hallucinations and convulsions (e.g. delirium tremens) when alcohol is withdrawn, and makes it difficult to overcome alcohol abuse and dependence.