(CNN) -- High school is an awkward time for many, if not most, teen-agers. But for gay teens, the awkwardness is sometimes compounded by the rejection -- and outright hostility -- of their classmates.

With school officials sometimes reluctant or unable to reach out to gay youth, students in some communities have turned to each other for help.

Last October's killing of 21-year-old Matthew Shepard, who was beaten into a coma and left tied to a fence rail in Wyoming, focused attention on the brutality that sometimes shadows gay youth. Though Shepard's case is an extreme example, study after study shows that gay teen-agers are more likely to be threatened with violence than straight classmates -- or be hurt, even killed, at their own hands.

"If you teach a young person that their life has no value, they'll treat their life like their life has no value," said Kevin Jennings, a former history teacher now working for the Gay, Lesbian and Straight Educational Network. "They will do things that show that they don't really respect themselves, such as use drugs or attempt suicide or engage in unprotected sex."

Activists like Jennings say their research shows schools often ignore verbal and physical assaults. That leads students to believe they have no support, leaving them feeling isolated, despairing.

"I'm not so much concerned about the kid who says "faggot" than what happens after that when there's a silence. What all the kids who will be listening think that is must be okay to say that," Jennings said.

Conflicting community values a challenge

School administrators say conflicting community values can keep them from offering the kind of sensitivity training that might limit attacks on gay teens.

"You have to show sensitivity and openness, and at the same time not be so sensitive and so open that you are promoting something that certain portions of your parent population and students would be opposed to," said Paul Houston, a spokesman for the American Association of High School Administrators.

But studies have shown that gay teens are more likely to be victims of physical violence and threats, and are four times more likely to report suicide attempts than other students. So some of their peers are stepping in where their school leaders might feel constrained.

The brutality of the Mathew Shepard case refocused attention on violence against gays

Support groups key

For Chris Thornton, a student in Durham, North Carolina, it began when she told a friend she had a crush on her female basketball coach. After that, just going into the girls' locker room was an ordeal.

"It got to the point where they wouldn't change around me. And it got uncomfortable for me, so I would go change somewhere else," she said.

Chris became depressed, even suicidal. After her grandmother's intervention foiled a suicide attempt. Chris turned to a local group of gay and lesbian students called the North Carolina Lambda Youth Network.

"It gave me some friends, because I didn't have any friends that were like me, that I knew about, because I was pretty much isolated," she said. "It gave me some community."

She went on to start a gay-straight alliance at her high school. It's one of 500 groups for gay students that have sprung up in 30 states over the last 10 years.

"Because there are a lot of silent voices out there. There are a lot of people who have been through the same stuff I have, get beat up every day."

Michael Bisogno, too, has started a support group for gay and lesbian teen-agers: He was forced to come to terms with his sexuality after a lunchtime attack by as many as 15 students who backed him up against a fence at his New Jersey high school.

"They were all against me, poking, punching, prodding, kicking, yelling, 'Oh, that's the faggot. Kill the faggot. Are you the faggot?' " Bisogno said. "They're telling you you're gay, like they're telling you you're a faggot. I couldn't even tell myself."

In Michael's case, school authorities went to police -- which also forced Michael to reveal his sexuality to his parents.

Michael spoke at a vigil for Shepard in Washington, D.C. just after Shepard's death.