Alcoholism: Genetic or Learned?
Posted: Saturday, December 05, 2009
by Gregory Lewis
PopGnosis
A popular t-shirt in my area reads, "Key West is a drinking town with a fishing problem." The Florida Keys has a reputation for being a drinking destination. Too often the destination part is literal, as marooned partiers descend into permanent inebriation, having left their place as productive members in society behind for the comfort of rum. "Time flies when you're having rum," goes one saying. I am fortunate to have met many good people in a state of recovery from drug abuse and alcoholism while living down here. As most of you already are aware, alcohol abuse is drug abuse.
In 2000 Bridgitt F. Grant, PhD, determined that one in four children in the U.S. were growing up in a home where alcohol abuse was taking place (Grant, 2000).
How is it that two children can have the same biological parents, grow up in the same home, and one becomes alcoholic, but not the other? The subject is understandably a well studied one. The traditional method of finding out if a disease or trait is caused by heredity or environment is the twin study. Since twins are genetically identical and tend to grow up under similar conditions in the same family, if both twins show the trait, it might be environment or genetic. If only one of the twins shows a trait such as alcoholism, then the environment is to blame.
The subject gets a little complicated, as even monozygotic twins (same egg) can either share a single placenta (monochorionic), or be nourished by their own individual placentas (dichorionic). Some diseases, like schizophrenia, have clearly been shown to be somehow related to environmental factors, even prenatal ones. This is because when only one of two twins gets the disease, it is usually in the case of dichorionic twins, with separate placentas. In twins that shared the placenta, both twins usually succumbed to the disease.
In a 2008 study published in the Journal of Abnormal Psychology, researchers attempted to look at children of twins, and their parents, to determine what the environmental causes of alcohol were, if any. They asked, "Were the children of alcoholics at higher risk for alcohol use disorders than children of non-alcoholic parents? The researchers concluded that environment, meaning parental role models are the primary factor in determining where and how alcoholism began in an individual. This doesn't mean that all children who grow up in a family where alcohol abuse is present will themselves become alcoholic. But it does mean that if a child grows up to become alcoholic, it has a lot to do with having grown up with alcoholism in the family (Hendershot, et al., 2009).
So, there is no "alcoholism gene". But, genetics do play a role in the ease of becoming an alcoholic.
As it turns out, different ethnic groups tend to have differing abilities of processing alcohol. Genes now have names. Caucasian people often have a gene called ALDH2. What this gene does is encode a protein that helps the liver oxidize alcohol quicker. You might say that Caucasians can "handle their liquor." Unfortunately, being able to handle the short term effects of liquor means drinking more of it, and drinking more of it, well, you get the picture.
Asian people, on the other hand, have a similar, but less active genotype called ALDH2*2, which does nothing to process alcohol. The consequence of this is that people who belong to any of several Asian groups tend to be highly sensitive to the short term effects of alcohol. They report hesitancy toward becoming inebriated (Slutske, et al., 2008). Persons who lack the ALDH2 allele, but carry the ALDH2*2 allele will "think twice" before having that second drink.
Similar genetic differences have been shown in people of African, as well as American Indian descent (Goedde, et al., 1992).
The conclusion of these examples is that alcoholism is learned behavior, but our genetic makeup helps it along. The origins of alcohol abuse begin in your family. That doesn't mean you will become alcoholic, but for those who struggle with the problem, that's usually where it began. Small children, of course, typically don't drink. So there are a lot of factors along the way that will tip the scales of a drinking problem one way or the other. If you express a certain genotype, in combination with having grown up in a climate of alcohol abuse, it means you will have to seriously consider where that second drink will take you.
References:
Goedde, H. W., Agarwal, D. P., Fritze, G., Meier-Tackmann, D., Singh, S.,
Beckmann, G., . . . Chen, L. Z. (1992, January). Distribution of ADH2 and
ALDH2 genotypes in different populations. Human Genetics, 88(3), 344-346.
Grant, B. F., PhD. (2000, January). Estimates of US Children Exposed to Alcohol
Abuse and Dependence in the Family. American Journal of Public Health,
90(1), 112-115.
Hendershot, C. S., Neighbors, C., George, W. H., McCarthy, D. M., Wall, T. L.,
Liang, T., & Larimer, M. E. (2009). ALDH2, ADH1B and Alcohol Expectancies:
Integrating Genetic and Learning Perspectives. Psychology of Addictive
Behaviors, 23(3), 452-463.
Slutske, W. S., D'Onofrio, B. M., Turkheimer, E., Emery, R. E., Harden, K. P.,
Heath, A. C., & Martin, N. G. (2008). Searching for an Environmental Effect
of Parental Alcoholism on Offspring Alcohol Use Disorder: A Genetically
Informed Study of Children of Alcoholics. Journal of Abnormal Psychology,
117(3), 534-551.
This Article has been viewed 1,254 times. (Not updated in real-time.)
Top-level comments on this article: (6 total)very informative and I totally agree with itPlease log in to respond to this comment.Thank you Patrick.Please log in to respond to this comment.
Very informative article Gregory.I like reading your articles.Looking forward to read more of your articles.Please log in to respond to this comment.Thank you Kenny.Please log in to respond to this comment.
Well thought out study on this seemingly prevalent problem. Where alcoholism in families is concerned, the members of that family who are not alcoholics nor heavy drinkers, must and do endure the revolting, irresponsible, and life destroying behavior of the drinkers, until which time they are able to remove themselves from their company. Family has to stop short of suicide.Please log in to respond to this comment.
Thanks for reading my "story" and becoming a fan. I am a recovering alcoholic. I've wondered why I became one, but it really doesn't matter. The key is how do I remain in recovery. The article is well written and researched. Thanks. Any information and education on the topic is good, but probably for loved ones, not the active acloholic who isn't interested. I'll try to figure out how to join your fan club.Please log in to respond to this comment.
» left by efoghorjos
from Bonny Island, Nigeria 2 years 25 days ago.
18 fans. Follow efoghorjos on twitter!I quite agree with you that alcoholism is more of a problem related to environmental influence than genetics. Thanks for your research.Please log in to respond to this comment.
Very informative article. I also grew up in an alcoholic family. I do not like alcohol at all and have poor tolerance of people who are intoxicated. 3 out of 7 of my siblings became alcoholic. One is a recovered alcoholic, the other 2 deceased. Even 2 beer will provoke nausea and vomiting with me. One of my sisters (the recovered one) said that I was so afraid I would become alcoholic I created this psychosomatic "illness" to prevent it.BlessingsPlease log in to respond to this comment.
We want your comments! If you can read this, you don't have javascript enabled, so you can't use this comment system. Please enable javascript.