UPDATE: The World Health Organization on Monday proposed adding gaming disorder to its new comprehensive manual of disease classifications, raising an immediate debate over whether it merits a separate designation.

Some U.S. experts said it will make little difference when it comes to helping people with the disorder, at least in the United States, but others said it would give legitimacy to a disorder that many people are reluctant to recognize.

The WHO added both online and offline gaming disorder to its latest draft of the International Classification of Diseases manual, called ICD-11.

This isn’t about kids spending a few hours in the basement playing “Fortnite” or “Call of Duty.” As with any medical disorder, the person affected must be seriously impaired.

“Gaming disorder is characterized by a pattern of persistent or recurrent gaming behavior (‘digital gaming’ or ‘video-gaming’), which may be online or offline,” the manual says.

The symptoms listed by WHO echo symptoms for other addictive or compulsive disorders. They include: a lack of control over gaming; giving gaming precedence over other life interests and daily activities; and continuation or escalation of gaming despite negative consequences.

“The behavior pattern is of sufficient severity to result in significant impairment in personal, family, social, educational, occupational or other important areas of functioning,” WHO said.

"Having recognition from the WHO is significant," said Dr. Petros Levounis, chair of psychiatry at the New Jersey Medical School at Rutgers University.

WHO’s ICD-11 is used widely outside the United States for classifying all disease. In the U.S., the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) is used to define mental illness. It mentions gaming disorder in its latest edition (DSM-5) but says more research is needed before listing it as a separate disorder.

“The ‘gamers’ play compulsively, to the exclusion of other interests, and their persistent and recurrent online activity results in clinically significant impairment or distress. People with this condition endanger their academic or job functioning because of the amount of time they spend playing,” it says.

Douglas Gentile of Iowa State University has done some of the influential research into the possibility of gaming addiction.

"I and many others had assumed that the gaming is not really a problem but is a symptom of other problems," he told NBC News. Many thought it was somehow a failure of morals or self-control

Gentile's team followed children who played games for several years.

"That's not what we found. We found that when kids became addicted, their depression increased, their anxiety increased, their social phobia increased and their grades decreased," Gentile said.

When kids were able to back off from obsessive gaming, their symptoms reversed, he said.

Gentile thinks medical organizations, health insurers and others should pay attention to the WHO designation.

"This isn’t an issue of opinion. It’s an issue of science," he said.

"This is a major scientific and medical organization. They don’t do things lightly and without reason."

The American Psychological Association has long fought to get the WHO's ICD used over the DSM when determining health insurance coverage.

Levounis said he hoped WHO's designation would boost research that got sidelined in the 1980s, when tobacco companies, then being sued for selling addictive and deadly products, argued that tobacco was not unique and that companies should not be penalized for selling addictive products.

"They basically were saying that any behavior can be addictive," Levounis said. "This whole mayhem set us back maybe 20-30 years. Now there is renewed interest and excitement."

In the U.S., it's important for one major reason: Health insurance won’t pay for treating someone for a disorder that doesn’t exist.

“That’s where the rubber meets the road,” said Keith Whyte, executive director of the National Council on Problem Gambling.

And even if there is a designation, it can be difficult to find treatment and to get insurance companies to pay for it.

“Gambling addiction has been in the DSM since 1980 and we still struggle to get routine reimbursement,” Whyte said.

For one thing, health insurance companies don’t have to cover mental and behavioral disorders.

“This is something the Affordable Care Act was going to address but it’s still [regulated] at a state-by-state level,” Whyte said.

“What we have found is that when you are dealing with insurance companies, it depends on what state you are in and who your therapist is.”

And that presumes people even recognize that they have a problem, Whyte added.

Just as with gamblers, gamers may think they are “professionals.” That makes a gambling or gaming disorder different from a substance abuse disorder.

“You can’t become a professional drinker or a professional smoker,” Whyte said.

“But gamblers feel like the more they play, the better they get. The better they get, the more they win. So quitting is the last thing you want to do. You’re one bet away from winning everything.”

In the end, however, winning is not the goal. Someone who gambles once or twice for fun will buy an island if they win a big jackpot. A gambling addict, Whyte said, puts it right back into the game.

“Addiction is not about winning. Addiction is about staying in action,” he said.

The Entertainment Software Association was preparing a statement but in the past has fought against any classification of gaming addiction.

"Legitimate science, objective research and common sense all prove video games are not addictive," the association said in a recent statement to NBC News. "By misusing the word addiction, which is a medical term, society demeans real compulsive behaviors, like alcoholism and drug abuse, which deserve treatment, compassion and care."

Gentile said his research shows that some children do indeed become addicted and he estimated that anywhere between 1 percent and 10 percent of kids who play games develop a disorder.

"That’s over 3 million children making serious damage to their lives because of the way in which they are gaming," he said.

PREVIOUS STORY: People who spend countless hours playing video games could soon be diagnosed with a mental health disorder.

The World Health Organization (WHO) will add "gaming disorder" to its International Classification of Diseases next year. That means doctors can now diagnose someone with the condition.
According to the WHO, the problem comes when gaming takes priority over other life interests and activities.

The behavior must persist for at least one year to be diagnosed, but that time can be shortened in severe cases.

A therapist in Michigan says people who suffer from this have a unique set of symptoms. 

"These are individuals who are preoccupied with gaming or through out the day when they are engaged with daily activities," Dr. Travis Johnson said. "It's also individuals who experience withdraw who think about gaming."

Channel 3 spoke to an employee at Epikos Comics, Cards, & Games in Hixson about the issue. He says he doesn't believe this new disorder will have a big impact on the gaming industry. 

"Maybe it is something to recognize, but at first blush it seems a little over blown for such a large world organization to be pointing out something that honestly every nerd in here knows somebody," Will Park, Assistant Manager of Epikos Comics, Cards, & Games, said. "It's atypical, but everybody knows the corner case."

Channel 3 also asked viewers on Facebook to weigh in on the WHO's decision.

"You can be addicted to anything," one viewer said. "Some addictions have worse side affects than others."

Another said, "now people will be trying to draw disability and sit and play games!"

The American Psychiatric Association has not recognized gaming addiction as a mental illness as of yet.