"Disorders due to addictive behaviours are recognizable and clinically significant syndromes associated with distress or interference with personal functions that develop as a result of repetitive rewarding behaviours other than the use of dependence-producing substances", writes the WHO.

On Tuesday, the World Health Organization added "gaming disorder" to its list of recognised and diagnosable diseases, as part of its 11th revision of the International Classification of Diseases.

"The new catalogue, which still needs to be approved by United Nations member countries, so-called "gender incongruence" is now listed under "conditions related to sexual health", instead of "mental, behavioural and neurodevelopmental disorders".

Dr Shekhar Saxena, director for the department for mental health from the WHO, told Euronews in a conference call, that video gaming disorder "can be present at any age" but particularly in adolescents and the young. Symptoms include impaired control over gaming, increasing priority of gaming over other life interests, and continuation or escalation of gaming despite negative consequences.

How will the World Health Organization classification of gaming disorder affect Americans?

"It enables us to understand so much about what makes people get sick and die, and to take action to prevent suffering and save lives", WHO Director-General Tedros Adhanom Ghebreyesus said as the ICD was published. How many hours do you think is normal to play video games each week? The DSM-5 calls out "Internet Gaming Disorder" but says it's a condition that warrants more clinical research and experience before it can be classified in the book as a formal disorder.

In its latest edition of the International Classification of Diseases, "gender dysphoria" - or transgenderism, in layman's terms - is not listed as a mental disorder any longer, but as a "gender incongruence", which has also been moved out of the mental disorder category.

37 percent of gamers say they have made at least half a dozen good friends through gaming.

"Video gaming is like a non-financial kind of gambling from a psychological point of view", said Griffiths, a distinguished professor of behavioral addiction at Nottingham Trent University.

Today was the first preview of the new ICD-11 codes, which included updates to designations for antibiotic resistance to better align with the Global Antimicrobial Resistance System (GLASS), so that "antimicrobial resistance patterns can be documented properly".

The ICD-11 isn't yet finished, though: The publication won't be endorsed as a final release until 2019, and won't be fully adopted until 2022.