A study by Stanford University researchers has found that for a growing number of people being online isn’t a necessity or convenience, but can turn into an addiction marked by compulsive behavior that gets out of control.

In a telephone survey of 2,513 randomly selected adults nationwide, researchers found that more than one in eight people reported at least one sign of problematic Internet use. Those include compulsive use of the Internet to check e-mail, make blog entries, visit Web sites or chat rooms.

Researchers said such compulsive behavior is similar to behavior by people suffering from substance abuse or impulse-control disorders: A repeated, intrusive and irresistible urge to perform an act that may be pleasurable at the moment but can lead to significant personal problems.

Stanford's Impulse Control Disorders Clinic has seen an increasing number of patients reporting an unhealthy attachment to Internet use, according to Dr. Elias Aboujaoude, the director of the clinic and lead author of the study on Internet addiction.

"We often focus on how wonderful the Internet is, how simple and efficient it can make things," Aboujaoude said. "But we need to consider the fact that it creates real problems for a subset of people."

According to the research, the most typically affected individual is a single, college-educated white man in his 30s who spends about 30 hours a week on non-essential Internet use.

"Not surprisingly, online pornography and, to some degree, online gambling, have received the most attention, but users are as likely to use other sites, including chat rooms, shopping venues and special-interest Web sites," Aboujaoude said. "Our survey did not track what specific Internet venues were the most frequented by respondents, but other studies, and our clinical experience, indicate that pornography is just one area of excessive Internet use."

The study found that:

• 68.7 percent of respondents were regular Internet users, which is consistent with other studies.

• 13.7 percent found it hard to stay away from the Internet for several days at a time.

• 12.4 percent stayed online longer than intended very often or often.

• 12.3 percent had seen a need to cut back in Internet use.

• 8.7 percent attempted to conceal non-essential Internet use from family, friends and employers.

• 8.2 percent used the Internet as a way to escape problems or to relieve a negative mood.

• 5.9 percent felt their relationships suffered because of excessive Internet use.

— Don Kazak