Is Alcoholism Genetic?

A Look at the Biological and Environmental Factors Behind Alcoholism

By Jon Relyea

INTRODUCTION

The topic of Alcoholism is very relevant to contemporary psychological research as alcoholism has shown increasing prevalence over the years. But, should the development of Alcoholism be attributed to environmental factors, genetic factors, or a combination of both?

DEFINITION

Many people have heard of alcohol-related disorders such as alcohol abuse and alcohol dependence. So what exactly defines Alcoholism? According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), Alcoholism is a disease characterized by four main symptoms¹:

· Repeated cravings for alcohol.

· Inability to control the amount one drinks at one sitting.

· Physical dependence exhibited by physiological bodily reactions to the intake of alcohol.

· Increased tolerance to alcohol.

BIOLOGICAL PROCESS OF ALCOHOL CONSUMPTION

Though alcohol in general exists in many chemical forms, the type found in beverages is ethyl alcohol, or ethanol (CH₃CH₂OH)². In most popular alcoholic beverages, ethyl alcohol is a colorless liquid that is derived from the fermentation of various fruits and sugars. Alcohol is very water soluble, and therefore once it enters the body, it almost immediately finds its way into the bloodstream. Similarly, it is capable of entering into vital organs, as well as through the blood-brain barrier. Needless to say, ethyl alcohol has the ability to affect many physiological processes in the body.

Upon entering the bloodstream, the body immediately begins metabolizing the alcohol through the liver at a rate of approximately one drink per hour, meaning twelve ounces of beer, 1.25 ounces of hard liquor, or five ounces of wine.

Though the body has this natural filter, consumption at a rate faster than the metabolism can process will disrupt not only one’s biological processes, but also one’s behavior. This is due to the fact that alcohol in the brain causes neurotransmitter levels to fluctuate - such as serotonin, dopamine, and GABA – all of which play various roles in behavior.

BIOLOGICAL FACTORS IN ALCOHOLISM

Consuming alcoholic beverages is a behavioral choice. But, is it possible that some people are genetically pre-disposed to high amounts of consumption? According to a 2004 study on genetics and alcohol dependence, “Family studies have surely demonstrated the family aggregation of alcohol dependence, finding a three- to four-fold prevalence of this dependence among first-degree relatives when compared to subjects of the general population.”³ Similarly, recent twin-family studies suggest that there is an increased likelihood of alcohol dependence if parents or other family members are alcoholics. So, if the numbers suggest that alcoholism is likely to occur in multiple first-degree relatives, what might be the cause? Psychologist Philip Hogue suggests that often times risk-taking behavior (such as the abuse of alcohol) is influenced by unbalanced serotonin levels – a neurotransmitter imbalance that could very easily be passed down genetically.⁴

ENVIRONMENTAL FACTORS IN ALCOHOLISM

Environmental influences on alcoholism are usually related to behavioral modeling. It is not unlikely that a child, or even a young adult, may develop a problem with alcohol if other members of the family or peers exhibit common alcohol misuse.⁵ A strong example of this that most of us have witnessed is the social pressure to consume alcohol upon entering college – sometimes in large quantities. An additional environmental factor in over-consumption and alcoholism come from societal pressures. Alcohol is often encouraged as a remedy for social inhibitions, stress relief, and considered necessary to have a good time.

INDIVIDUAL DIFFERENCES

When generalizing about the factors behind problem-drinking, it is important to remember that every individual is affected by alcohol differently. While many physical and behavioral factors related to intoxication are common, no two people will respond to alcohol consumption exactly the same way.⁶ This concept continues to challenge alcohol-related research, because researchers must consider such a wide array of variables, including gender, age, body mass, heritage, rate of consumption, type of beverage consumed, etc.

In short, there are an infinite number of scenarios that lead individuals to become intoxicated from alcohol consumption, and replication of these factors is close to impossible.

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COMBINING FACTORS

Alcoholism continues to be a central subject in psychological and medical research. This is probably because little is known about what precise biological or environmental factors influence the development of this disease. It is currently the most common conclusion that alcohol-related disorders develop from a combination of multiple social and genetic factors alike. For example, a person who develops alcoholism may be genetically predisposed to alcohol tolerance, but may not have come across this disposition had he/she not felt social pressures to binge drink during young-adulthood. On the same note, someone with a family history of alcoholism will not inevitably become alcoholic themselves.

ANALOGY

One might think of alcoholism as being similar to a gambling habit. It is possible that some individuals may be genetically predisposed to compulsive behavior, which would allow a negative gambling habit to develop more easily during adulthood. Having this disposition, however, does not guarantee that the individual will become a compulsive gambler. Meanwhile, someone that is not in any way genetically likely to exhibit compulsive behavior may be influenced by winning a jackpot at a casino on the first try, and therefore find that gambling is enjoyable and even develop a negative habit. Or, had this same person never won at gambling, they may also be at risk for a negative habit if his/her friends enjoy frequent trips to the casino and their social setting commonly involves gambling.

REFERENCES

1. “Alcoholism: Getting the Facts.” Publications, National Institute on Alcohol Abuse and Alcoholism. [available online] http://www.niaaa.nih.gov/publications/booklet.htm, 2001.

2. Boggan, W. “Alcohol and You.” General Chemistry Case Studies. Kennesaw State University.[available online] http://chemcases.com/alcohol/, 2003.

3. Guilherme P., Homero P. “The Role of Genetics in Alcohol Dependence.” Rev. Bras. Psiquiatr., May 2004, vol.26 suppl.1, p.54-58.

4. Hogue, Phillip A. “The Relationships Among Propylthiouracil, Impulsivity, and Substance Abuse.” Dissertation Abstracts International: Section B: The Sciences & Engineering. Vol 65(4-B), 2004, 2137. US: Univ Microfilms International.

5. Tarter, Ralph E; Vanyukov, Michael. “Alcoholism: A developmental disorder.” Marlatt, GAlan (Ed); VandenBos, Gary R (Ed). (1997). Addictive behaviors: Readings on etiology, prevention, and treatment. (pp. 43-67). Washington, DC, US: American Psychological Association. xxv, 930 pp.

6. Heath, Andrew C; Madden, Pamela AF; “Genetic and environmental risks of dependence on alcohol, tobacco, and other drugs.” Plomin, Robert (Ed); DeFries, John C (Ed); et al. (2003). Behavioral genetics in the postgenomic era. (pp. 309-334). Washington, DC, US: American Psychological Association. xxiii, 608 pp.