Do you find yourself becoming easily addicted to things? Caffeine, sugar, Netflix perhaps? Good news! Modern research on addiction suggests it may not entirely be your fault. Addiction studies have uncovered a strong link between genetics and addictive behavior. The National Institute on Drug Abuse (2016) estimates that your genes could account for up to 50% of your susceptibility to addiction. Now, when your family gives you a hard time for that insatiable sweet tooth of yours, you can slyly respond with, “It’s genetic!”
In a 2016 study, researchers were able to breed two genetically different types of rats, one of which was more prone to addiction than the other. The more prone rats were called “high responders”, bHR for short, and the others “low responders”, bLR for short. The rats were taught to self-administer cocaine as they pleased and, as their genetics would predict, the bHR rats self-administered cocaine at a higher rate (Flagel et al., 2016).
You might be wondering: does this mean that people with genes for addiction are destined to become addicts? Well, not exactly. You see, different environments and experiences in our lives can change how our cells interpret our DNA. When this happens, the traits encoded by our genes can change too. The study of this phenomenon is called epigenetics and it really only “began in earnest in the mid Nineties” * (Bell, 2013). It is strong testimony to the influence of the environment on our behavior.
| The researchers of this 2016 study sought to understand the epigenetic effects of repeated drug use on addictive behavior in the bHR and bLR rats. After learning to repeatedly self-administer cocaine, the rats were put through a period of abstinence in which they received no drug for a month. Then, they were allowed to self-administer again. Once again, as their genetics would predict, the bHR rats relapsed at a faster rate than the bLR rats. Moreover, the bLR rats now showed similar levels of a certain protein in their nucleus accumbens – a known pleasure center of the brain – as the bHR rats (Flagel et al. 2016).
Just as genetic screenings have been developed to determine people’s risk of breast cancer and other heritable diseases, genetic screenings for addiction could be on the horizon. Screenings can help people make better decisions regarding their health care, but genetic screenings for addiction could also have other potentially problematic implications. Consider the following: if one were to be genetically screened at birth and found to be prone to addiction, to what extent in the future could they be held responsible for their addictive behavior in say, a courtroom? Moreover, what sort of behavioral and psychological effects would knowing your own propensity for addiction have on you and those around you? As science continues to develop a genetic approach to addiction, it is these types of difficult questions that our society must begin to grapple with in order to prepare for unintended consequences in the future.
- Flagel, S. B., Chaudhury, S., Waselus, M., Kelly, R., Sewani, S., Clinton, S. M., … Akil, H. (2016). Genetic background and epigenetic modifications in the core of the nucleus accumbens predict addiction-like behavior in a rat model. Proceedings of the National Academy of Sciences of the United States of America. 113(20). Retrieved from http://www.pnas.org/content/113/20/E2861.
- NIDA (2016). Genetics and Epigenetics of Addiction. Retrieved from https://www.drugabuse.gov/publications/drugfacts/genetics-epigenetics-addiction
- Bell, C. (2013, October 16). Epigenetics: How to alter your genes. The Telegraph. Retrieved from http://www.telegraph.co.uk/news/science/10369861/Epigenetics-How-to-alter-your-genes.html