The 12 teenagers and young adults, some in ripped jeans and baggy T-shirts, sit in a circle, chewing gum and fidgeting as they shyly introduce themselves.
"I'm 12 years old," one boy announces with a smile. "I love playing computer games. That's it."
"It's been good to sleep" says another, a 17-year-old with spiky hair, now that he's no longer on the computer all day.
The youths are patients at China's first officially licensed clinic for Internet addiction, a downside of the online frenzy that has accompanied the nation's breathtaking economic boom.
"All the children here have left school because they are playing games or in chat rooms everyday," says the clinic's director, Dr. Tao Ran. "They are suffering from depression, nervousness, fear and unwillingness to interact with others, panic and agitation. They also have sleep disorders, the shakes and numbness in their hands."
According to government figures, China has the world's second-largest online population -- 94 million -- after the US.
While China promotes Internet use for business and education, government officials also say Internet cafes are eroding public morality. Authorities regularly shut down Internet cafes -- many illegally operated -- in crackdowns that also include huge fines for their operators.
State media has also highlighted cases of obsessed Internet gamers, some of whom have flunked out of school, committed suicide or murder. Nonetheless, Internet cafes continue to thrive, with outlets found in even the smallest and poorest of villages. Most are usually packed late into the night.
Kimberly Young, a clinical psychologist in Pennsylvania whose 1998 book on Internet addiction has been translated into Chinese, says she's not surprised the Chinese would face problems with Internet overuse.
While treatment programs were virtually nonexistent in the US a decade ago, she said, dozens of clinics and countless individual therapists such as herself offer counseling and treatment in her country.
Tao's government-owned clinic, which began taking patients in March, occupies the top floor of a two-story building on a quiet, tree-lined street on the sprawling campus of the Beijing Military Region Central Hospital.
A dozen nurses and 11 doctors care for the patients, mostly youths aged 14 to 24 who have lost sleep, weight and friends after countless hours in front of the computer, often playing video games with others online.
Some come voluntarily, while others are checked in by their parents. Many say their online obsessions helped them escape day-to-day stress, especially pressure from parents to excel in school.
Some can't stop playing games, while the older ones tend to be addicted to online chats with the opposite sex, Tao says. Others are fixated on designing violent games.
Tao, a psychiatrist for 20 years who specializes in treating addiction, estimates that up to 2.5 million Chinese suffer from Internet addiction, though others are skeptical.
"As the number of the Netizens grows, the number of the addicted people will grow as well, but we should not worry about the issue too much," says Kuang Wenbo, a professor of mass media at Beijing's Renmin University. "The young men at the age of growing up have their own problems. Even if there was no Internet they will get addicted to other things."