Although the world wide web has been around for less than a generation, Dr Christian Montag from the University of Bonn, said they had found a gene in people who could not drag themselves away. Most were women.
Dr Montag said that, biologically speaking, internet addiction had the same genetic cause as smoking addiction.
He said: “Internet addiction is not a figment of our imagination. Researchers and therapists are increasingly closing in on it.”
Describing the impact of the genetic variant on those who had it, he said: “Within the group of subjects exhibiting problematic internet behaviour this variant occurs more frequently, in particular, in women.
“The sex-specific genetic finding may result from a specific subgroup of internet dependency, such as the use of social networks or such.”
He and colleagues drew their conclusions after interviewing more than 800 people about their internet habits, including how often they thought about it and how much of an impact they felt if it was denied to them.
They then looked at the genetic makeup of 132 who seemed most addicted to the net, comparing them to a ‘healthy’ control group.
They found that many of the 132 had the same genetic variant, which has previously been linked to nicotine addiction.
More studies were needed, he said, but added: “The current data already shows that there are clear indications for genetic causes of internet addiction.
“If such connections are better understood, this will also result in important indications for better therapies.”