"It was shown that Internet addiction is not a figment of our imagination," Montag, who is based at the Department for Differential and Biological Psychology at the University of Bonn, said.
The study showed that the thoughts of the addicts revolve around the Internet during the day; and a belief that their well-being is severely impacted if they have to go without access to the Internet.
The same genetic variation found to occur frequently in online addicts has already been linked to other forms of addiction, including nicotine addiction, and to loneliness and depression.
"What we already know about the nicotine acetylcholine receptor in the brain is that a mutation on the related gene promotes addictive behavior," Montag said.
