We’re always looking for the reasons behind addiction, in order to better understand how we might treat it. We know there are genetic and hereditary components, that gender and poverty can play a role, and that mental illness is a big contributor. Now, researchers think that an ancient retrovirus might explain why some people suffer from addiction.

A retrovirus is composed of ribonucleic acid, or RNA, instead of DNA. When it infects a cell, it essentially inserts a copy of itself into the DNA of the host cell, permanently altering it. Retroviruses are responsible for certain types of cancer, and HIV, the virus that causes AIDS, is a retrovirus. The particular one found by this study has been around so long that it predates modern man. It dates back at least to Neanderthals, our closest extinct relative that lived between 400,000 and 40,000 years ago. It’s called the HK2 virus, and it turns out that drug users are about three times more likely than the rest of the public to have remnants of it in a certain gene in their DNA.

The virus is present in a gene called RASGRF2, which the researchers called the pleasure gene because it increases the activity of dopamine in the brain in about 5 percent to 10 percent of the population. They believe that that group of people might be more predisposed to addiction.

The researchers, who were comprised of scientists from Oxford University and Athens, tested drug users in Glasgow, Scotland and in Greece. They found that 34 percent of the drug users in Glasgow had the virus present in their DNA, as opposed to 9.5 percent of the local population. Among the Greek drug users, 14 percent had remnants of the virus, compared to six percent of the country’s population.

HK2 is present in all humans, but it only appears in the RASGRF2 gene in up to one in 10 people. Those people aren’t only prone to drug abuse, but to any sort of addictive behavior. In 2012, a different study found that RASGRF2 is connected to the reinforcement of alcohol use, and binge drinking in particular, through the release of dopamine.


As mentioned above, there are more factors than just the physical that go into addiction, and finding this one bit of causation isn’t going to lead us to a miracle cure. Still, it could lead to scientists better understanding addiction and being able to create better treatments. Knowing that there is this genetic component at play could also do a lot to de-stigmatize drug addiction by moving the public away from the idea that it’s about a lack of self-control or a moral failing.

If you or a loved one need help with quitting drugs or alcohol, consider Asana Recovery. We offer medical detox, along with both residential and outpatient programs, and you’ll be supervised by a highly trained staff of medical professionals, counselors, and therapists. Call us any time at (949) 438-4504 to get started.