LESSON 4: WHAT CAUSES ALCOHOLISM?

Overview:
Alcohol acts as a depressant - it decreases the ability of the nervous system to perform its functions. Anyone who consumes an alcoholic beverage is affected by it, but may not be an alcoholic. Any person who needs the effects that alcohol produces in their body can be considered an alcoholic.

Since alcoholism was formally recognized as a disorder in the 1950's, its cause has been under debate. The controversy has been between the effect of the environment verses the effect of heredity. In one sense, alcoholism is environmental, since no one becomes an alcoholic unless he or she makes the choice to take a drink. Others point to heredity as the cause since many times alcoholism tends to occur in families, sometimes extending over several generations.

In the 1980's C. Robert Cloninger conducted a study in Sweden that examined the occurrence of alcoholism in adopted children of alcoholic parents. A summary of the results shows the following:

• There are two types, or degrees of alcoholism - severe, or Type II, alcoholism, and less severe, Type I.
• Many children of Type II alcoholics themselves become Type II alcoholics, regardless of their environment.
• Children of Type I alcoholics tend to become Type I alcoholics. However, many of these children, influenced by environmental factors, become Type II alcoholics.
• Males are much more likely to become alcoholics than females.

In l987, Cloninger proposed a theory based on his findings. His theory suggested that three personality types make up the two types of alcoholics and that the traits shown by these have a biological basis. Gene regulated activation of chemicals in the nervous system controls each trait. These alcohol-susceptibility genes determine how the central nervous system reacts to the environment. For one individual, a stimulus may activate one chemical, but in another person a different chemical may be activated. For simplicity, the chemicals may be called A (produces active or adventuresome behavior), B (inhibits such behavior and acts as a control) and C (produces behavior that is characterized as reward-seeking).

According to this theory, the inheritance of a nervous system that produces large amounts of chemicals B and C and only small amounts of chemical A is predisposed to becoming a Type I (environmentally influenced) alcoholic. A person who inherits a nervous system that produces large amounts of chemical A and small amounts of B and C is susceptible to becoming a Type II alcoholic. The study indicated the susceptibility genes controlled eating disorders in females and alcoholism in males. Further studies continue to look at molecular biology for the possible genetic origins of alcoholism.

Objective:

1. To evaluate how genetic makeup and environment may lead to alcoholism

Nebraska State Science Standards:

12.7.1	Students will develop an understanding of personal and community health.
12.7.5	Students will develop an understanding of natural and human induced hazards.

Vocabulary:

nature vs. nurture (heredity vs. environment)
alcoholism

Activity:
The following activity is offered as a suggestion to help you learn more about the material presented in the Medical Ethics program.

Activity 1: Alcoholism - Heredity or Environment?
Bob White is a Native American who was adopted at birth. It was known he had an identical twin who remained on the Indian reservation.

Bob's adoptive parents stressed the importance of his heritage and encouraged him to be involved in area Sioux groups and activities. In his involvement he has noticed a high incidence of alcoholism among Native Americans.

Bob is now 25 and is planning to marry Betty Lou who is also 25. Betty Lou's parents are both alcoholics.

Bob and Betty Lou consume alcohol only on social occasions. They have read that alcoholism is probably a multifactoral, genetically influenced disorder (that may also have environmental influences). They are now concerned that any children they may have would have a predisposition for alcoholism.

Consider the following ethical questions:

1. How does environment and inheritance interact to affect the appearance of a condition such as alcoholism?
2. Should Bob worry about his genetic makeup since Betty Lou's parents are alcoholics?
3. Should a genetic screening be required when a child is put up for adoption?
4. How does society treat people with a stereotyped label?
5. Does society assign a "self-fulfilling prophecy" prejudice to certain races or ethnic groups?
6. Do you believe that alcoholism is a disease? a genetic disease?
7. Should one be allowed to open adoption records to acquire genetic information?

Bibliography:
Genethics Workshop. July 1992. Personal Communication.

1996. Biology (Issues and Decision-Making). Addison-Wesley Publishing Company. Menlo Park, California. p. 13-14.