Kids spend an increasing fraction of their formative years online, and it is a habit they dutifully carry into adulthood. Under the right circumstances, however, a love affair with the Internet may spiral out of control and even become an addiction.

Whereas descriptions of online addiction are controversial at best among researchers, a new study cuts through much of the debate and hints that excessive time online can physically rewire a brain.

The work, published June 3 in PLoS ONE, suggests self-assessed Internet addiction, primarily through online multiplayer games, rewires structures deep in the brain. What’s more, surface-level brain matter appears to shrink in step with the duration of online addiction.

“I’d be surprised if playing online games for 10 to 12 hours a day didn’t change the brain,” says neuroscientist Nora Volkow of the National Institute on Drug Abuse, who wasn’t involved in the study. “The reason why Internet addiction isn’t a widely recognized disorder is a lack of scientific evidence. Studies like this are exactly what is needed to recognize and sette on its diagnostic criteria,” if it is a disorder at all, she says.*

Defining an addiction
Loosely defined, addiction is a disease of the brain that compels someone to obsess over, obtain and abuse something, despite unpleasant health or social effects. And “internet addiction” definitions run the gamut, but most researchers similarly describe it as excessive (even obsessive) Internet use that interferes with the rhythm of daily life.

Yet unlike addictions to substances such as narcotics or nicotine, behavioral addictions to the Internet, food, shopping and even sex are touchy among medical and brain researchers. Only gambling seems destined to make it into the next iteration of the Diagnostic and Statistical Manual of Mental Disorders, or DSM, the internationally recognized bible of things that can go awry with the brain.

Nevertheless, Asian nations are not waiting around for a universal definition of Internet addiction disorder, or IAD.

Read the article at Scientifc American