The Genetic Link of Alcoholism: Heredity and Risk

Introduction

A great deal of attention and research has recently been concentrated on the genetic link of alcoholism and on the possibility of accounting genetically for drinking behavior. Early studies found reliable genetic transmission of alcoholism. Much of this research focused on the offspring of alcoholics and on the biochemical or neurological abnormalities they inherit that possibly lead to pathological drinking. Other studies focused on a constellation of personality traits — concentrating on impulsiveness and antisocial activity — that can end in alcoholism.

According to Holden (1985, p. 38), "A decade ago such a theory (of inherited antisocial personality and alcoholism) would have been dismissed out of hand." Today, this viewpoint has gained broad acceptance among psychologists. New research has created more detailed deterministic models of alcoholism based on biological concepts, which have had a significant impact on the thinking of both public and clinical workers.

This paper examines the genetic link of alcoholism, reviewing existing research on the subject to draw conclusions about its ability to describe and explain alcoholism. Particular attention will be given to the idea that alcoholism is a disease determined by biological predisposition (Milam and Ketcham, 1983).

Is Alcoholism Inherited?

More and more scientific evidence suggests that alcoholism has a genetic component. However, the actual gene that may cause it has yet to be discovered. Studies of laboratory animals, in addition to various human test subjects, demonstrate that genetic factors play a key role in the development of alcoholism, but experts still do not know how large a role they play.

American Academy of Child and Adolescent Psychiatry statistics show that children of alcoholics are four times more likely than other children to become alcoholics. However, it must be noted that environmental factors could be a contributing factor in many of these cases.

Family, twin, and adoption studies suggest that alcoholism definitely has a genetic component. In 1990, Blum et al. proposed an association between the A1 allele of the DRD2 gene and alcoholism. The DRD2 gene is the first candidate gene that has shown promise of an association with alcoholism (Gordis et al., 1990).

Research suggests that genes greatly influence the likelihood of alcoholism occurring. Through extensive studies, it has been shown that a predisposition to alcoholism may be inherited.

According to Ohlms (1991), alcoholism is a "chronic, progressive, incurable disease, characterized by loss of control over alcohol and other sedative drugs." Alcoholism has three stages, each with distinct symptoms. In the first stage, alcoholism involves relief drinking, amnesia, and drunk driving. The transition between the first and second stages involves a loss of control over the disease, as well as over one's life (Ohlms, 1991). The middle stage includes family problems — such as divorce and dishonesty — along with job problems, legal problems, and moral issues. The final stage is characterized by physical deterioration (Ohlms, 1991). These stages occur in this general order in all alcoholics, with corresponding symptoms, making alcoholism a reliable and predictable disease.

Alcoholism is a national problem and a threat to society. Ninety-six percent of all alcoholics die of alcoholism. Less than one percent become mentally incapacitated, and the remaining four percent seek help and attempt to recover from the disease. Alcoholism is the third leading cause of death in the United States, and the leading cause in the 15- to 24-year-old age group (Ohlms, 1991). For those who do seek help, recovery rates range from 70 to 80% (Ohlms, 1991). Alcoholism treatments include support groups such as Alcoholics Anonymous, rehabilitation centers, and counseling.

Genetics influences nearly everything in the human body. There are many physiological differences between alcoholics and non-alcoholics, and these differences can be observed in relatives of alcoholics even when the relative is not an alcoholic. For example, in alcoholics, the liver has a hard time storing sugar and using it gradually; an alcoholic's liver often burns alcohol instead of sugar. Partly because of this, alcohol can act more as a stimulant than a depressant in alcoholics (Royce, p. 147). For this reason, many alcoholics lose control over their drinking.

The Genetic Link

For hundreds of years, observers have suggested that alcoholism is passed from one generation to the next. Morel believed that parental drunkenness produced alcoholic excess in the first generation and worsened as it was passed through subsequent generations, until the fourth generation became sterile and the family line ceased (Murray and Stabenau, 1982). However, these early views were largely dismissed. Jellinek posed three questions aimed at understanding the genetic effects on alcoholism: "(1) Does parental alcoholism cause such damage to the germ cells as to produce defects in the first generation? (2) Does parental alcoholism bring about a true mutation in the offspring? (3) Is there a hereditary liability factor involved in alcoholism?" (Murray and Stabenau, 1982, pp. 135–136).

The first two questions suggest that alcoholism may itself create an inherited predisposition to the condition, while the third suggests that it is the genes of the parent that place offspring at higher risk. Nevertheless, these questions remained largely theoretical, and the research that followed was minimal (Murray and Stabenau, 1982).

In recent years, family studies have shown that the children of alcoholics are three to four times more likely to develop alcoholism than the children of non-alcoholics (Shuckit, 1999). Approximately twenty percent of sons and brothers of alcoholics become alcoholic, and five percent of daughters and sisters (Goodwin, 1991). These observations demonstrate the genetic link in the development of alcoholism.

Most researchers today believe that both genes and environment together determine alcoholism risk. In the past, research on alcoholism in families focused mainly on environmental factors, including how family members interact with one another and the influence of peer pressure on the development of alcoholism (Vietnen, 2002).

Sociologists have examined how economic status or the availability of alcohol affects the prevalence of alcoholism. Until recently, genetic analysis had been limited to disorders with a clear biological basis, such as cystic fibrosis, rather than disorders that appeared to result primarily from environmental influences, such as alcoholism.

Conclusion

Alcoholism affects families, friends, neighbors, employers, acquaintances, and many others, and is closely linked to some of the most difficult social issues, including crime, homelessness, teen pregnancy, and domestic violence. Children of alcoholics are at increased risk because of both genetic and environmental factors. Evidence suggests that children of alcoholics may face a heightened risk for alcoholism in the same way that children of diabetics face a heightened risk for diabetes.

Additionally, children of alcoholics tend to develop unhealthy living patterns. They may be unable to trust themselves or others, handle uncomfortable feelings, or build positive relationships. Children of alcoholics who lack these skills are also at higher risk for school failure, depression, increased anxiety, and trouble with alcohol and other drugs. For this reason, it is important to understand as much about the disease as possible.

There have been many studies on the influence of genetics on alcoholism, and the majority point toward genetics playing a significant role in the development of the disorder. Finding genetic causes of alcoholism is only the beginning. In the future, researchers may be able to study individuals with genetic predispositions across different environments and examine interactions between environmental and genetic factors. The outcomes may lead to new procedures and treatments that could halt alcoholism before a potential alcoholic ever takes a first drink.

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