There's a critical difference between video game fans and over-the-top fanatics. Playing obsessively for long hours each day can unbalance your stability – and we don’t mean how you walk, though maybe that's also a risk. The World Health Organization now adds "gaming disorder" to its list of mental health conditions. For those with a full obsession, gaming "takes precedence over other life interests and daily activities," the United Nations agency says after studying obsessive players. It can cause anxiety and depression, as well as disrupting jobs, educations, family or social lives.

The Geneva-based organization estimates that 2 to 3 percent of gamers might be diagnosed as compulsive players needing treatment to regain balanced lives. "I've seen kids who really can't not play," says Dr. Steven Schlozman, a pediatric psychiatrist at Massachusetts General Hospital. "When the console gets taken from them, they fall apart in exactly the way that people fall apart when the daughter takes away all the booze from the alcoholic father in those old shows."

Now that it's officially classified as a worldwide phenomenon that merits attention and treatment, there's a standard description to help diagnose sufferers and a billing code for insurance payments. Across varied languages and social, cultural and medical traditions, the agency's 191 member nations recognize common definitions of ailments.

For now, the American Psychiatric Association doesn’t consider gaming disorder to be a new mental health problem. Instead, the medical group calls it “a condition warranting more clinical research and experience." Some U.S. professionals generally see compulsive video gaming as a symptom of addictive behavior, not a new malady. “There really hasn't been a good study of what kind of treatment works," says Andrew Saxon, a professor of psychiatry and behavioral science at the University of Washington in Seattle. "We're in the realm of semi-experts giving recommendations. . . . A lot more work would have to be done to look at the treatment."

Ex-player says: "My life was there, online. I could easily put away six to eight hours a day without even thinking about it." – Tim Walrod, 28, of Massachusetts

Psychologists say: "Video game addiction might be a real thing. But it is not the epidemic that some have made it out to be." -- Patrick Markey of Villanova University (Villanova) and Christopher Ferguson of Stetson University (Florida)

Caution for parents: "This doesn’t mean every child who spends hours in their room playing games is an addict. Otherwise medics are going to be flooded with requests for help." -- Joan Harvey, British Psychological Society