FAIRFAX COUNTY, Virginia (CNN) -- It was just after 7 a.m. and Cassie Graham was lighting up her second cigarette of the morning.
Cassie Graham, a 17-year-old high school senior, joined a school support group to help her quit smoking.
A school bus passed her parked car, a sign that that it was time for the 17-year-old high school senior from Fairfax County, Virginia, to stop smoking and head to class.
If Graham has her way, that will be the last time she ever lights up.
"It's getting pretty bad," said Graham who started smoking at age 15. "It used to be fun and now I have to smoke. I know that it's not normal to smoke all the time, and I have to find some way to quit." Watch more on Cassie's struggle to kick the habit »
The Centers for Disease Control and Prevention estimates that 20 percent of high school students smoked cigarettes last year. Smoking rates among ninth- to 12th-graders have remained stable for the past five years.
"When I see a young kid smoking, it's just so frustrating because I actually know the power of tobacco to cause disease," said Dr. Otis Brawley, chief medical officer for the American Cancer Society.
Nearly half of all adults in the United States who suffer from emphysema and 40 percent with chronic bronchitis are smokers, the CDC reports.
More than 430,000 Americans die each year from smoking-related causes, the American Lung Association estimates.
While researchers have a good idea how to help adults kick the habit, little information is available on what to do to assist teenage smokers.
"It's really hard for somebody who is a teenager in high school to stop smoking, even if they wanted to stop smoking," Brawley said.
Peer pressure can be tremendous among young smokers, he said. What's more, Brawley noted, it may be difficult for a teenager to seek help from a doctor or counselor without a parent's knowledge.
Smoking cessation drugs, patches, gum and lozenges are not approved by the Food and Drug Administration for anyone under 18.
So what's left to help a teen kick the habit? Support groups.
Cassie Graham signed up for a 10-week smoking-cessation class held during one of her free periods at Robinson Secondary School in Fairfax County.
"I'm not of legal age to smoke," Cassie said. "So I was kind of skeptical at first, like 'Am I going to get in trouble for going to this class?'"
Samuel Wagner, a substance abuse counselor at the school, didn't discount Graham's concerns about showing up for the session.
"It's very gutsy," he said, "because students do have that fear that if they come to this group, all we're doing is rounding them up to get them busted."
Wagner, along with school counselor, Tami Marcheski, sat down with five students who've signed up for the support group called Not-on-Tobacco or N-O-T.
The American Lung Association designed the program a decade ago for regular smokers, ages 14 to 19, who want to quit.
Marcheski called the success rate at her school outstanding. "Thirty-seven percent of kids have quit and 60 percent reduced the number of cigarettes smoked," she said.
This particular session was called "quit day."
Cassie and her classmates talked openly about their reasons for wanting to quit. Almost everyone mentioned health concerns and the expense of the habit.
David Thomas, 18, added "I want to smell better. I won't have to use cans and cans of Axe. I can work out longer and I don't have to worry about carrying mints around."
Lia Pisa-Relli said she started smoking when she was 12. Now at the age of 17, she worries that she has a lot of breathing problems. "I want to be able to run. I can't even run up the stairs. I can't even walk up two flights of stairs. It's pretty bad."
The counselors spoke with the teens about how to handle nicotine withdrawal symptoms. They passed out lollypops and stress balls to take their mind off cravings. They urged the students to lean on one another and their families for support.
Their final exercise of the day was to write down their concerns and fears about quitting on note cards.
Cassie read her comments aloud to the group: "One of my biggest concerns was that I wouldn't be able to quit, but now I know if I just stick to it and actually try hard to quit then I'll be able to."
She and her classmates crumpled up the cards and tossed them in the trash as if they were throwing away a bad habit.
Cassie's final words in class: "I can quit now."