An article from CNN - London reports on a new theory about addiction.
Could it all be do to an ancient retrovirus?
An ancient retrovirus that predates modern humans may be the key to what causes some people to suffer from addiction according to some scientists. Researchers studied drug users in two cities and found they were about three times as likely than the general population to have remnants of the HK2 virus within a particular gene in their DNA. The virus goes as far back to at least Neanderthals and is present in the RASGRF2 or "pleasure" gene. The gene increases the activity of dopamine in the brain in about 5-10% of people.
That portion of people could be more at risk for addictive behavior. The team, from the universities of Oxford and Athens, found the virus in 34% of drug users tested in Glasgow, Scotland, compared to 9.5% of the local population, and in 14% of Greek patients, compared to 6% of that country's population." (CNN) The gene has also been linked to binge drinking in the past.
Retroviruses have the ability to inject their DNA into the genome of the host and the third time they have been linked to harmful effects in humans since the discovery of HIV.