Is addiction genetic? Whether you develop an addiction as the result of abusing drugs or alcohol is determined partly by genetics and partly by environmental factors. Having a family history of addiction doesn’t automatically mean that you will develop one, just as having no family history isn’t enough to guarantee you won’t.
The roles of genes and environment in addiction are inextricably linked. To understand how each affects your risk for addiction, it’s important to have a clear understanding of the mechanics of addiction and dependence.
Addiction and Dependence
Addiction and dependence aren’t the same thing, and each can occur independently of the other. An addiction is characterized by compulsively using drugs or alcohol despite negative consequences. You may want to stop, or you may try to stop, but you’re unable to do so.
The first time you use drugs or alcohol and get the desired effects, your brain associates the substance use with pleasure, and it craves the experience again. Each subsequent time you use the substance, the association in your brain between it and the pleasure it elicits grows stronger. It becomes increasingly difficult to turn away from using the substance in question.
Physical dependence is characterized by changes in the structures and functions of the brain that lead to withdrawal symptoms when the drug use is discontinued.
When you abuse drugs or alcohol on a regular basis, the activity of your brain chemicals change to compensate for the frequent presence of the substance of choice. This leads you to develop a tolerance for drugs or alcohol, and it takes increasingly higher doses to get the desired effects.
Eventually, these changes in brain function cause you to feel more normal when you’re using the substance than when you’re not. When you withhold the substance, the former level of activity of the brain chemicals rebounds, and your body responds with the onset of withdrawal symptoms.
Genetics vs. Environment in Addiction and Dependence
The National Council on Alcoholism and Drug Dependence notes that genetics account for about half of the risk of developing an addiction or dependence, and environment accounts for the other half. But that doesn’t necessarily mean you have a 50-50 chance of developing an addiction. The types of genes and where they come from matter, and the interplay between genetics and environment is complex.
For instance, sex plays a role in the genetics of addiction, according to the National Institute on Alcohol Abuse and Alcoholism. Genes passed down to you by a family member of the same sex have a greater influence on addiction than those passed down by a family member of the opposite sex. Additionally, the combinations of genes have an influence on overall risk. Genes govern the metabolism of alcohol and the way the brain functions and can play different roles in increasing the risk of addiction as well as dependence.
Environmental factors can mitigate some genetic factors. For example, if your grandfather had alcoholism and you inherited some of those genes, but you grew up in a strict religion that frowned on drinking, this environmental factor would likely preclude the genetic factor from playing a dominant role in the development of an addiction. But if you drank a lot in high school and continued to abuse alcohol in college, your risk of developing alcoholism would be increased.
The Bottom Line
Family history is just one factor in the development of a drug or alcohol addiction. Eventually, scientists may be able to develop genetic tests that may be used to not only predict whether someone might develop an addiction but also to develop very specific treatments based on an individual’s genes.
Before genes get involved in determining whether you’ll develop an addiction, you first have to experiment with a substance, and then you have to abuse it.
The environment has already had quite a say in the matter, and at that point, genetics will help determine whether you become addicted.