Jaysen Perkins used to spend up to six hours a day running missions with the U.S. Navy Seals.

Until it started hurting his social life.

And his grades.

The 16-year-old has spent the last year coping with a video game addiction, in this case to the military role-playing game Socom II.

"I probably noticed a problem about a month into playing Socom," Perkins says. "There's something about it -- I kept wanting to go back."

Jaysen's mother, Rebecca, also noticed the change in her son.

"Jaysen would get up to play in the middle of the night," she says. "I guess the behavior was addictive -- he was trying to play it any way he could."

So the Perkinses turned to Jaysen's therapist, Kim McDaniel, for help.

McDaniel, a licensed mental health counselor, treats Jaysen along with about eight others each week for problems related to gaming addiction at her private practice in Kirkland, Wash.

Her most common patients are 6-year-olds who've had trouble adjusting to other children in school and 12-year-olds who are struggling with the transition to middle school. She also helps adolescents like Jaysen. When parents bring these distressed children to McDaniel, she frequently discovers a connection to gaming.

"I often find that parents have nothing but the best intent with their children's relationship to technology," McDaniel says, "but there are a lot of myths out there."

One myth might be that video games are engrossing but not addictive.

"This is an exciting form of technology that kids really, really like," says David Walsh of the Minneapolis-based National Institute on Media and the Family. "As a psychologist, I understand why it's so engaging. It's Psych 101 -- stimulus and response."

And it goes beyond that.

Certainly, popular games such as the Grand Theft Auto series and online games like Socom II and EverQuest -- where multiple players can compete over the Internet -- are designed to engage the player, but what actually makes them addictive?

McDaniel points to what video game manufacturers call "the God effect."

"You're the center of the universe" in more addictive role-playing games, McDaniel says. "Which is very attractive for teenagers without a lot of power, psychologically, in the world."

Parents can discern between misuse and addiction if they notice two important telltale signs in their children: withdrawal and isolation.

"If you're a parent and your child is withdrawing, you might wonder if your kid is getting into pot or cocaine," says Hilarie Cash of Internet/Computer Addiction Services in Redmond, Wash. "The symptoms are very similar."

Cash and McDaniel are working on a parents' guide to gaming addiction in which they outline the symptoms to look for in young gamers -- something parents can prevent, they say, by regulating their children's gaming time.

"It's important to have the ground rules and the consequences clear from the get-go," says Walsh. "The time to discuss this is not when you're trying to impose the limits" after things have gotten out of control.

The video game industry agrees that the onus is on parents to monitor their children's playing time.

"Parents who supervise their children need to make sure that [video games] are used appropriately," says Carolyn Rauch, senior vice president of the Entertainment Software Association, the trade group that represents U.S. computer and video game publishers.

But gaming addiction isn't limited to children.

According to Maressa Orzack of Computer Addiction Services, located near Boston, adult gaming addicts "have other issues like depression. . . . These people are avoiding their own problems. Some of them want excitement, some of them want relief."

Orzack also believes the population of adult gaming addicts in the United States could be significantly high, though exact figures are difficult to ascertain. (The study of gaming and its effect on players is a specialized and still-developing field.)

Liz Woolley didn't wait around for more studies to emerge on the issue. She founded Online Gamers Anonymous in 2002, after losing her son, Shawn, to suicide that same year. He had become addicted to EverQuest while being treated for depression.

Devastated and angry, Woolley didn't know where to turn.

"I found out that [gaming addiction] is an underground epidemic," Woolley says. "A lot of people were going through the same thing, and there was no place to go for help."

So Woolley turned to Alcoholics Anonymous and adopted its 12-step program. "That was the best support group that I knew, with a success rate," she says.

Now, according to Woolley, the group's Web site, www.olganon.org, gets more than 300 visits a week.

"We want people to know that they're not alone," she says. "This can be a life-threatening addiction and it should be taken seriously."

When it comes to younger gamers, Kim McDaniel recommends traditional group therapy.

"For children under 10, social skills groups are an excellent resource," she says. "For adolescents, getting into a peer counseling group could be extremely helpful."

Jaysen Perkins hasn't joined traditional group therapy, but he has benefited from joining a group -- he's been attending a church youth group with friends and reclaiming old hobbies.

"I used to be heavy into basketball," he says of his days before Socom. "Now I've been playing basketball again, I've been going to high school football games. I've been going to that youth group with friends. . . . We're trying to keep my schedule busy."

Jaysen Perkins says he's back to playing basketball and engaging in other activities since his mother got him into therapy for a gaming addiction.