As described in Pediatric News, internet addiction is characterized by a "preoccupation, uncontrolled impulses, more usage than intended, tolerance, withdrawal, impairment of control, excessive time and effort devoted to the Internet, and impairment of decision-making ability.
The researchers, working under Dr Chih-Hung Ko, followed over 2000 seventh graders in order to determine that ADHD was the strongest predictor of Internet addiction among girls and that hostile boys (defined by the Buss-Durkee Hostility Inventory--DO NOT TRY THIS AT HOME!) were more likely than others to develop the addiction.
Dr Ko hypothesizes that kids with ADHD can master fast-paced internet games readily and their success at this is "addictive" as their brains release dopamine during the intense online activity. Hostile boys, on the other hand, may allow themselves to express their otherwise anti-social behavior and aggression in a relatively safe way by gaming on the internet
My concern as an adolescent physician is that the ADHD and hostility may lead to more harmful consequences when the online activities go beyond games to involve social networking sites. Impulsive teens with ADHD may "go places" they shouldn't or say things that are dangerous or harmful when they hit "Send" prematurely. Hostile teens may in turn find solace on any number of websites that encourage and nurture the kind of anger that we have all seen turn into treacherous life threatening pursuits or even terrorism
On a more creative and optimistic note, I hope that game designers will work with mental health professionals and use this information to create therapeutic games and activities to treat these hurting kids.
image from www.crenk.com