Anything really can be addicting given the right set of circumstances and the person involved, but MMOs have gotten a lot of attention for their addicting behavior, what with their constant "one more level" mentality and that need and desire to keep pushing forward to get to the bigger and better stuff. However, new info comes out saying that though the addictive qualities of a MMO can still be problematic, they might not be as terrible as other studies have suggested.

From the article:

While it is hardly news that some find the nature of massively multiplayer online games to be addicting, a new report from the UK's University of Bolton has found that while such games may not be quite as addictive as previously believed, they can still be “potentially damaging for players' work, home and social life.”

According to the study, Dr. John Charlton, Research Fellow in Psychology in the School of Health, Psychology and Sport, found that levels of video game addiction could be as much as 10 percent lower than earlier studies.

Explaining this differential, Charlton's report found that many reports classify gamers as addicted by using symptoms that are also used in the diagnosis of gambling addiction, something that Charlton flagged as inappropriate.

“This is my second research project in this field to confirm this outcome; that several symptoms researchers had thought were important in diagnosing computing-related addictions were actually only indicative of high, but non-addictive, involvement,” explained the university psychologist. “This means that taking them into account when conducting research gives an incorrect result - 10% higher than is correct.”

Read the full article over at gamasutra.com