It's believed that more than 2 billion people worldwide play video games. For most, it's a harmless past-time. But for others, it's an obsession. The World Health Organization now recognizes "gaming disorder" as an official mental health condition. But how does a player know when they have crossed the line? CGTN's Dan Williams helps us sort it out.

Early evening in the northwest suburbs of Chicago. And dozens of people are hanging out at a gaming lounge. It is a social, interactive gathering, with players linking up to enjoy the latest games.  

ABE SHIHADEH MANA DIGITAL DRIVE "PC gaming has taken it to the next level where people can come together, a lot of people are meeting through gaming and it has become like a social thing as well."

But as gaming increases in popularity, the concern over excessive gaming grows. In June, the World Health Organization classified 'gaming disorder" as a new mental health condition, including it in its latest edition of International Classification of Diseases. 

DOUGLAS GENTILE ASSOCIATE PROF. OF PSYCHOLOGY, IOWA STATE UNIVERSITY "I started my first study on video game addiction in 1999. And I thought that can't be right. They just mean my kid just plays a lot. And it turns out I was wrong. In study after study, we find there are a small subset of people who actually are gaming in a way which is very dysfunctional."

Dr. Kirk Moberg is the executive medical director at the Illinois Institute for Addiction and Recovery. He has seen first-hand the consequences of excessive gaming.

DR. KIRK MOBERG EXEC. MEDICAL DIRECTOR, ILLINOIS INSTITUTE FOR ADDICTION RECOVERY  "I generally see people when they have experienced severe consequences from an addiction like this. I'll give you an example of one of the most extremes that I saw was a young man in his early 20s, his parents were very concerned because he was playing video games 18 hours a day, to the exclusion of food and water."

The move by The WHO has been criticized. Some researchers believe excessive gaming is merely a symptom of an underlying mental health issue such as depression and not a stand-alone disorder. There are also concerns that the label 'gaming disorder' could fuel a moral panic over new technology that is already being blamed for playing a role in mass shootings.

"Anything in excess is a bad thing. So I think gaming disorder might be a way to put it but I feel it is just like an obsession that can happen with anything. An obsession with TV, an obsession with movies. You can become obsessed with anything not just video gaming."

DAN WILLIAMS CHICAGO "There's no doubt that a number of households across the globe will be concerned by so-called 'gaming disorder'. Experts are quick to point out it only impacts a very small minority. But it is hoped that this recognition of the issue will go some way to providing help for those that need it."

DOUGLAS GENTILE ASSOCIATE PROF. OF PSYCHOLOGY, IOWA STATE UNIVERSITY "It took 40 years before people recognized research and said alcoholism is a disease. I hope it doesn't take that long for gaming disorder because until we start accepting it as a real problem, people won't get the help they need."

For these gamers, the fun in gaming is clear to see, but like any activity, with excess comes issues. Dan Williams, CGTN, Chicago.