The new CNS Spectrums study was based on results of a nationwide telephone survey of more than 2,500 adults. Like the 2005 survey, this one was conducted by Stanford University researchers.About 6% of respondents reported that "their relationships suffered because of excessive Internet use." About 9% attempted to conceal "nonessential Internet use," and nearly 4% reported feeling "preoccupied by the Internet when offline."

　　About 8% said they used the Internet as a way to escape problems, and almost 14% reported they "found it hard to stay away from the Internet for several days at a time."

　　"The Internet problem is still in its infancy," said Elias Aboujaoude, a Stanford professor. No single online activity is to blame for excessive use, he said. "They're online in chat rooms, checking e-mail, or writing blogs. [The problem is] not limited to porn (色情) or gambling" websites.

　　Excessive Internet use should be defined not by the number of hours spent online but "in terms of losses," said Maressa Orzack, a Harvard University professor. "If it's a loss [where] you're not getting to work, and family relationships are breaking down as a result, then it's too much."

　　Since the early 1990s, several clinics have been established in the U. S. to treat heavy Internet users. They include the Center for Internet Addiction Recovery and the Center for Internet Behavior.

　　The website for Orzack's center lists the following among the psychological symptoms of computer addiction:

　　● Having a sense of well-being (幸福) or excitement while at the computer.

　　● Longing for more and more time at the computer.

　　● Neglect of family and friends.

　　● Feeling empty, depressed or irritable when not at the computer.

　　● Lying to employers and family about activities.

　　● Inability to stop the activity.

　　● Problems with school or job.

　　Physical symptoms listed include dry eyes, backaches, skipping meals, poor personal hygiene (卫生) and sleep disturbances.

　　People who struggle with excessive Internet use maybe depressed or have other mood disorders, Orzack said. When she discusses Internet habits with her patients, they often report that being online offers a "sense of belonging, and escape, excitement [and] fun," she said. "Some people say relief…because they find themselves so relaxed."

　　Some parts of the Internet seem to draw people in more than others. Internet gamers spend countless hours competing in games against people from all over the world. One such game, called World of Warcraft, is cited on many sites by posters complaining of a "gaming addiction."

　　Andrew Heidrich, an education network administrator from Sacramento, plays World of Warcraft for about two to four hours every other night, but that's nothing compared with the 40 to 60 hours a week he spent playing online games when he was in college. He cut back only after a full-scale family intervention (干预), in which relatives told him he'd gained weight.