The Link Between Genetics & Addictions
The human body contains around 100,000 genes. This information, enclosed in all cells in the body, can influence almost everything from the way a person walks, talks and responds to the world outside. Some of these genes might even have a role to play in addiction, influencing the way a person responds to specific drugs and the likelihood that a person will develop a dependence on specific drugs with even casual use. While all of this might sound exciting, as finding the “addiction gene” could mean the end to addiction once and for all, there are some serious limitations in the current understanding of addiction and genetics. While the studies suggest a link exists, much more work must be done before experts know what that link truly means, and what should be done about it.
In 2003, a major step forward was made in the understanding of human genetic information. The Human Genome Project, which was completed at that time, allowed researchers to identify all of the genes that made up human DNA, and the results were transferred to the public sector for future researchers to use. For the very first time, researchers had a good ideas of all of the genes that were in play in the human body, and with this information, they could begin to develop complicated studies that could compare a sample of one type of DNA with the types already sequenced in the Human Genome Project.
Modern studies on addiction and genetics can be conducted in many different ways, but commonly, researchers look for groups of people who have strong family histories of addiction. Families that have several documented cases of alcoholism, for example, or families that have several members with opiate addictions might make ideal test cases. Then, all of the members of the family are asked to donate blood samples, whether they are addicted or not. Researchers then analyze those samples and look for stretches of DNA that seem similar in people who are addicted, but dissimilar from people who are not addicted. Then, researchers compare that information with the Human Genome Project database, looking for genes that are known to control drug responses or brain chemistry. They then go back to the samples and look for mutations in those genes within the addicted families.
It all sounds simple enough, but there are some limitations to these tests. For example, some people may share all of the same genetic markers with their addicted family members yet they are not addicted themselves. Additionally, some people may have no addiction hallmarks and come from families with no history of addiction. These sorts of instances tend to skew results. In addition, with so very many genes in play, it can be difficult for researchers to know exactly what they are looking for. Finding the one needle in the haystack could take years or even decades of patient, diligent research.
Research on other conditions influenced by genetics may shed some light on the issue. For example, a specific set of mutations has been associated with breast cancer in women. According to the National Cancer Institute, about 12 percent of women who do not have the mutation will develop breast cancer, compared with 60 percent of the women who do have the mutation. As this information clearly demonstrates, having a specific genetic marker for a condition doesn’t automatically mean the person will develop the condition. Not all women with the genetic marker for breast cancer get breast cancer. Not all women who don’t have the genetic marker for breast cancer are safe from the disease. It’s clear that there are other factors at play, besides genetics.
According to the National Institute on Drug Abuse (NIDA), genetic information accounts for about half of a person’s vulnerability for addiction. There are many other factors that play a role in the development of an addiction issue, including:
- The friends people spend time with
- The age at which a person begins using drugs or alcohol
- The neighborhood the person lives in
- The availability of drugs and alcohol
- The presence of mental health issues
- The person’s gender
Put in very simplified terms, genes are a bit like suggestions for the cells to follow. They represent a vulnerability to addiction, perhaps, but they also are far from set in stone. Babies aren’t born doomed to become addicts in later life. Any gene, whether it’s associated with cancer, heart disease, addiction or some other health issue, must interact with the environment in some way. There must be a trigger that turns the gene on and allows the process to begin. Without the trigger, the gene may remain dormant. And some people develop the issues through lifestyle alone, even though they had no suggestions coming from their genes.
While addiction genes may need a push from the environment in order to turn on, there are several studies being performed that do suggest that there are specific genes in the human body that can work hard to help influence an addiction issue. Given a tiny push, these genes could spring into action and cause a serious problem to take hold.
Some of these studies have been performed in monkeys. Researchers have used monkeys in laboratories for years, and as a result, they know a significant amount of information about the genes available to monkeys and how specific genes influence a variety of health conditions. In one interesting study reported by the National Institutes of Health, monkeys with a specific type of genetic adaptation to a gene that controls serotonin drink more alcohol than monkeys that do not have this adaptation. If the monkeys with the adaptation are separated from their mothers and raised by other monkeys, they drink even more. This study indicates that a gene helps create a predilection for addiction, but that environment augments that tendency even more.
Some studies have been performed on human beings as well. For example, a study funded by the NIDA looked at 352 pairs of identical male twins and 255 pairs of fraternal male twins. The two pairs were asked to answer questions about how marijuana made them feel, and how much they enjoyed it. The responses by the identical twins (who share all of the same genes) were much more alike than the responses given by fraternal twins (who share only about half of their genes). While this study did not identify what specific gene is involved in marijuana enjoyment, it does seem to indicate that some genes are involved in how much a person enjoys the sensation of smoking marijuana, and this could have a great impact on a person’s likelihood of developing an addiction to marijuana. Enjoying the drug could lead the user to take the drug again, while disliking the drug could stop use from occurring again.
Some studies on humans rely on the habits that a family has in common. Since families are related through genetic materials, these studies seem to indicate a genetic process is at play, even though the genes that are directly involved in the process haven’t yet been highlighted. In one such study, the National Institute on Alcohol Abuse and Alcoholism reports that children of alcoholics are between four and 10 times more likely to become alcoholics themselves, as compared to people who have no close relatives who are alcoholics. They’re also more likely to begin drinking prior to age 27, and they tend to progress through the stages of alcoholism more quickly than people who do not have relatives who have alcoholism. Multiple studies seem to suggest a link between genes and alcoholism, and this is a field researchers are looking at quite closely.
The link between drug addiction and genetics was demonstrated in a similar study. In this study, as reported by Nature, people who were born to addictive parents but who were raised in adoptive families were more likely to become substance abusers than were people who were raised in the same environments but were born to non-substance-abusing parents. Again, this study cannot identify what genes made the people susceptible, and there may be one other minor problem with this study. People who grow up in adoptive families may feel alienated or isolated, as they’re not growing up with people they are genetically related to. This form of isolation could force them to make risky decisions and begin to experiment with substances, or it could lead them to depression that they attempt to medicate with drugs or alcohol. Must more research must be done before this link can be considered definitive.
It’s likely that researchers will continue to experiment with mice and monkeys, making small changes to their DNA strands and attempting to see how they respond when presented with the opportunity to drink or use drugs. Then, they may be able to make reasonable assumptions about how those genes work in humans. The ultimate goal may be to develop therapies that can help people recover from addictions through taking just the right kind of pill or using the right kind of therapy.
Living in the Moment
While this research is ongoing, and questions are still far from being answered, there’s little anyone can do. No pills have been designed to correct faulty genes, and there are no tests potential parents can run to see if they’ll pass the potential for addiction down to their children. But, knowing that addiction does at least have some genetic component, there are some reasonable things people can do:
- People with a family history of drug or alcohol abuse should not use those substances themselves. It’s best not to give the genes a boost from the environment.
- Parents with a history of substance abuse should encourage their children to avoid experimenting with drugs or alcohol during adolescence. The teen mind is more vulnerable to addiction, and it’s best to avoid all experimentation until that vulnerability has passed.
- Those with a family history should get early interventions for addiction instead of attempting to deal with the issue alone. Getting help early, and sticking with treatment, might be the best way to keep a lapse from becoming a major break.
- Families with addiction histories should keep open lines of communication about addiction and experimentation. Parents and children who discuss the topic openly and honestly can support one another effectively.
How We Can Help
At The Canyon, we specialize in providing effective addiction treatments that are rooted in sound scientific principles. We keep abreast of the research, so we can ensure that we provide our clients with the best care possible. If you’re struggling with an addiction issue, or you know someone else who is, please contact us and find out more about the help we can provide.
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