The proposed diagnostic criteria closely resemble the criteria for substance use disorders. The proposed criteria include:
1. Preoccupation with Internet games
2. Withdrawal symptoms (irritability, sadness, anxiety) when the Internet is not available or taken away.
3. Tolerance indicated by the need to spend increasing amounts of time playing Internet games.
4. Unsuccessful attempts to control participation
5. Loss of interest in other meaningful activities or recreation, except for Internet games
6. Continued use despite knowledge that the excessive use of the Internet use is causing problems.
7. Lying or other form of deceit regarding the amount of Internet gaming
8. Using Internet gaming as a means to escape or relieve negative feelings
9. Jeopardized important relationships, job, or limited occupational or educational opportunities due to Internet gaming.
As with other addictions, people with Internet gaming addiction may exhibit excessive use. Like other addictions, Internet use continues despite negative consequences. It's possible to envision addiction to other activities (besides gaming) that are unique to the Internet and/or computers. These include social media websites; chat rooms; online games; and virtual reality experiences. Many Internet-based activities also have real world counterparts. Examples are pornography websites, gambling, and online shopping. Online gambling may meet the criteria for gambling disorder and should be diagnosed as such.
It may be hard to imagine how the Internet could be "addictive." Our working definition of addiction guides us on this issue: "Addiction is the repeated involvement with a substance or activity, despite the substantial harm it now causes, because that involvement was (and may continue to be) pleasurable and/or valuable. The harmful consequences will partially depend on which Internet activities are involved. Pornography websites, gambling websites, and online shopping may increase financial debt at much faster rate than other activities. When the participation in these activities causes harm, or limits someone's life, we begin to wonder about addiction.
There are differences between Internet-based vs. face-to-face relationships. These differences have been a source of interest to researchers. Many people have relationships based on Internet communications. Sometimes these relationships are entirely based on Internet communication. It appears these relationships are here to stay.
So are these relationships helpful or harmful? Some people who have difficulty relating to others face-to-face. These folks may have a better social life because of the Internet. Thus, having a lively Internet social life does not make someone an Internet addict. So, how much is too much? A determination of this nature needs to evaluate the magnitude of negative consequences it creates. Such a determination would need to consider the individual's entire life and the range of activities.
Some activity addictions, such as gambling addiction and sex addiction, operate within the brain's reward system LINK. These activities increase levels of the neurotransmitter dopamine. However, Internet addiction may act through different neurochemical pathways. More research is needed in this area.
Approximately 86 percent of Internet addiction cases present with at least one other DSM diagnosis (Block, 2008). This is true of most addictions. The high likelihood of co-occurring mental disorders suggests that Internet addiction may not be a distinct disorder, but rather an effect of other disorders. For instance, someone with Social Phobia might rely on the Internet as their sole source of social interaction.
Currently there are numerous reports about video game, exercise, and shopping addiction. Perhaps some of these addictions will merit inclusion in a future DSM. Regardless, Internet addiction is a growing phenomenon that is associated with serious harm to some people. Because of this trend, research will likely increase in this area.