Internet addiction may have a molecular basis, German researchers say, linked to a genetic variation that also plays a major role in nicotine addiction.

Researchers at the University of Bonn studying people and their Internet habits found a significant number who exhibit problematic behavior, where all their thoughts revolve around the Internet during the day and they feel their well-being is severely impacted if they have to go without it.

A comparison of the genetic makeup of the problematic Internet users with that of healthy control individuals found such people are more often carriers of the genetic variation linked to nicotine addiction, the university reported Wednesday.

"What we already know about the nicotinic acetylcholine receptor in the brain is that a mutation on the related gene promotes addictive behavior" by activating the brain's reward system, researcher Christian Montag said.

"It seems that this connection is not only essential for nicotine addiction, but also for Internet addiction," he said.

"If such connections are better understood, this will also result in important indications for better therapies. (UPI)