According to the World Health Organization, playing a lot of video games could be a symptom of a mental disorder.
The WHO's 11th international diagnostic manual is due in 2018. It will be the first update since 1990.
Just as technology has evolved in that time, mental disorders have too; the draft of the upcoming list of health conditions includes criteria for an unnamed game-related disorder.
"Health professionals need to recognize that gaming disorder may have serious health consequences," said Vladimir Poznyak, a member of the WHO's Department of Mental Health and Substance Abuse.
"Most people who play video games don’t have a disorder, just like most people who drink alcohol don’t have a disorder either," he added. "However, in certain circumstances overuse can lead to adverse effects."
The Independent reports that only 2 to 3 percent of gamers reported five or more symptoms associated with gaming disorder, according to a 2016 University of Oxford study of 19,000 gamers in Germany, the U.K., the U.S. and Canada.
The lead director of the study, Dr. Andrew Przybylski, said that the study provided evidence of "the potential new problem of 'internet gaming disorder.'"
Researchers at ESET found an even higher prevalence of addiction-like symptoms in a study of 500 individuals. Their data showed that 10 percent reported spending 12 to 24 hours in a row playing games.
"Gaming is highly addictive," said ESET security specialist Mark James, "and it is no wonder so many respondents from our study admit to playing them for so long."
Psychology Today reports that internet gaming disorder is not officially recognized in the by the American Psychiatric Association's mental diagnostic book, the DSM-5, but that the APA may include it in later editions.
Symptoms of the disorder include a strong desire to play video games, increased time spent playing them, and withdrawal symptoms when games are taken away. Like other types of addiction, gaming disorder affects a person's ability to function in everyday life.
USA Today reports that the WHO's draft criteria for gaming disorder are "recurrent" game-playing sessions resulting in "impaired control over gaming," "increasing priority given to gaming," and "escalation of gaming despite the occurrence of negative consequences."
WHO spokesperson Tarik Jasarevic said that game disorder is not limited to time spent in front of screens. It includes symptoms that manifest outside of gaming as well.
Though the disorder has not yet been named, the WHO's manual will include a description. It does not yet mention treatment options or prevention methods.