Sandals strapped around her chilly toes, 13-year-old Heather Davis stood with her friend Suzanne Ledford, glitter dabbed on her eyelids, at the front of the Jefferson Middle School auditorium on Monday night.

They were there as student volunteers for a forum on youth, handing out bright yellow paper booklets titled "Risky Teen Behavior" to more than 700 parents, teachers and school officials who filed in to listen to the insights and advice of author Patricia Hersch.

For her book, "A Tribe Apart: A Journey Into the Heart of American Adolescence," Hersch shadowed eight teenagers in Reston for three years. She writes about a teenage culture that is largely ignored by adults.

It's a culture in which even good students host unsupervised house parties with beer and tequila and marijuana and sex. It's a culture in which Hersch describes teenagers so isolated that they don't even think to go to an adult for help.

The Arlington County Council of PTAs and a host of other public entities, including Arlington Hospital and the Arlington public schools, sponsored the forum as part of their effort to openly address concerns about sex, drugs, alcohol and violence among the county's youth.

"I have a 10-year-old daughter, and ever since she was a toddler, people have said to me, 'Wait until she is 12. She will stop talking to you,' " said Melinda Patrician, a parent who helped coordinate the forum. A follow-up session will be held Feb. 28.

"There are a lot of parents who don't want to accept that," Patrician said. "We have to talk to them and get beyond the fear of what teenagers are going to say."

Wearing blue blazers with their middle school's name sewn on the front, Heather and Suzanne thought about the forum and whether it would be a success, whether it would be worth all this effort by all these adults.

"I don't know," Heather said, even as she smiled and waved at her mother. "I really don't know if they can understand us."

Parents are always inquiring about how their teenage children are coping, offered Suzanne, "but it's the little things that they don't ask about, and some things you don't want to tell them about."

In the auditorium, the forum was starting. Microphones were being tested. People were jostling for seats. Still, Heather and Suzanne wanted to speak. It's the little things, Heather said, like understanding why she wants to be "weird" and wear sandals in the winter.

Little things, Suzanne said, like the stress at school that comes from boys who pinch them and flirt with them in the halls. And little things, they said, like their worries that they don't have enough time to go to their locker between classes.

Heather said she recently had a chat with her father after he found a note from a friend expressing anxiety about sex.

"My father said to me, 'I know you have a life that I don't know about,' " Heather said. "He told me, though, that I could come and speak to him any time."

That sort of honesty is what Hersch was starting to speak about inside. Heather and Suzanne filed in, sat down and listened for a while. They listened as Hersch explained that adults do not give teenagers enough respect and do not listen enough. They listened as she talked about the problems of drugs among teenagers, as adults in the audience sighed in concern.

"What is missing is not a program," Hersch said. "What is missing is us. We have to get back in their lives."

Afterward, Heather and Suzanne sat on the floor outside and waited for parents to pick them up. They liked some of what they heard, they said. Some they disagreed with. But in the end, they thought the forum was a great idea.

"When she spoke about us wanting adults to trust us, to listen to us, I was, like, that is so true," Suzanne said. "I was thinking, this is how my life should be, but it's not."