HUNTINGTON, W.Va. (WSAZ) -- When you think "addiction," you tend to think nicotine, alcohol and drugs.

The Internet may be the latest addition to that list. More and more research shows that the Web has people hooked, and even Marshall University's psychology department is studying that trend.

Justin Cox is an admitted Internet junkie.

"Yeah, it would be hard to break it now – to completely stop using the Internet," he said. "The convenience is all there."

So, what classifies if someone is an addict? According to Dr. Kimberly Young, who recently wrote the book "Caught on the Web," between 5 and 10 percent of Americans are addicted to the Internet. That's roughly 15 to 30 million people.

Kristina Isaacs, who is working on her master's in clinical psychology, said she would feel a void without the Internet.

"I think I would feel lost," she said. "I can't imagine I'd do everything I do without the Internet."

Isaacs said the widespread nature of Internet use could mask a potential addiction problem for an individual.

"It's more socially accepted," Isaacs said. "You don't have to be ashamed you're addicted to the Internet because everyone uses it. It's so easy to see the time that can pass away when you're on there."

Stephanie Heck is a Web designer and computer programmer with her own Huntington blog. She said the Web is as diverse as the people who surf it.

"With women, it took on the form of online shopping," she said.

Cox said the Internet has become something of a worldwide addiction.

"Not just people are addicted to it," he said. "You take the Internet away now, economies would collapse, countries would fail."

The Web site netaddiction.com has a test to determine if you could be classified as an Internet addict. It consists of 20 multiple choice questions and is available here at WSAZ.com.