Addiction may be caused by an ancient virus still lingering in our DNA

Researchers believe an ancient retrovirus still lingering in our DNA may the reason for addiction, the Daily Mail reported.

A team that included researchers from Oxford and Athens have traced the genomes of drug users in the UK and Greece to find out what features they had in common.

They discovered addicts were likely to have HK2, an ancient virus that tends to gather near a gene in charge of dopamine release.

While we all have ancient viruses that date back to our primate ancestors, they are not thought to be factors that can determine a person character thousands of years later.

"[N]ow we have strong proof that HERVs can be pathogenic. For the first time, we are able to make a distinction between cause and effect in HERV pathogenicity," Dr Gkikas Magiorkinis of the University of Athens is quoted as saying by the Daily Mail.

The study found has to have variations or multiple copies of HK2 in various parts of the body.

"Even more intriguing, some of these varied copes seem to be capable of coding more viruses in the human host - while most retroviruses are 'broken' blueprints, which are no longer capable of something so powerful," the report stated.

Professor Aris Katzourakis, from the University of Oxford, told the Daily Mail: "We know of clear biological roles for a small number of human endogenous retroviruses.

"However, there has never before been strong evidence in support of a role in human biology of an endogenous retrovirus that is unfixed, in other words not shared by all individuals in the population.

"Our study shows for the first time that rare variants of HK2 can affect a complex human trait. The replication of this finding in the distinct Athens and Glasgow cohorts is particularly important."